straight pipe atv

[400exrider26400]

anyone running straight pipe on there atv ?

[Flynbryan19]

Originally posted by 400exrider26400
anyone running straight pipe on there atv ?

Only if they're idiots and want their riding spot closed down... :rolleyes:

[400exrider26400]

Originally posted by Flynbryan19
Only if they're idiots and want their riding spot closed down... :rolleyes:



i dont ride in riding area
i ride in the woods

[Flynbryan19]

Originally posted by 400exrider26400
i dont ride in riding area
i ride in the woods

There are MANY other items you can put on your 400 that will yeild much great performance gains than having a straight pipe. Look at any of the pro level quads in any of the forms of racing on here. They ALL have silencers on their quads. Riding w/o a silencer doesn't do anything to help the already bad rap our sport has and only irratates people and gets you kicked outta the places you ride. Besides the fact that it sounds like crap....

[400exrider26400]

Originally posted by Flynbryan19
There are MANY other items you can put on your 400 that will yeild much great performance gains than having a straight pipe. Look at any of the pro level quads in any of the forms of racing on here. They ALL have silencers on their quads. Riding w/o a silencer doesn't do anything to help the already bad rap our sport has and only irratates people and gets you kicked outta the places you ride. Besides the fact that it sounds like crap....



I RIDE IN THE WOODS AND NO ONE CARES
and no its my 400ex thats straight pipe its my lt230 beater bike

[400exrider26400]

Originally posted by 400exrider26400
I RIDE IN THE WOODS AND NO ONE CARES
and no its my 400ex thats straight pipe its my lt230 beater bike

i meant not my 400ex*

[usp4u]

someone WILL care when your irresponsibility starts a fire in those woods. and then of course we all suffer b/c you are a tard who thinks loud=fast.

[400exrider26400]

Originally posted by usp4u
someone WILL care when your irresponsibility starts a fire in those woods. and then of course we all suffer b/c you are a tard who thinks loud=fast.


when did i say loud equals fast ?
im only running straight cus it sounds good .
lots of power lost but better loud than quiet

and whats the ****ing chance of starting a fire

[Flynbryan19]

Originally posted by 400exrider26400
I RIDE IN THE WOODS AND NO ONE CARES
and no its my 400ex thats straight pipe its my lt230 beater bike

lol, you just don't get it do you buddy......? Straight pipes are retarded and someone WILL care. Its people like you that feel your special that ruin it for all of us. If you don't care enough about anyone else's opinion of our sport, then do us a favor and take that "beater bike" to the scrap yard and take up another hobby. Your not gonna find someone on here that shares your belief unless it some snot nose kid that apparently like yourself doesn't have the common courtesy for others and their property. Loud pipes DO get our areas shut down.

Its quite obvious you already had your mind made up that it was a good idea to put some idiotic obnoxiously loud fart pipe on your beater quad before you came on here and now your getting your feelings hurt because others don't share your opinion.... Sorry, your not going to change my belief on the subject and you'll find few others that will disagree.

[400exrider26400]

Originally posted by Flynbryan19
lol, you just don't get it do you buddy......? Straight pipes are retarded and someone WILL care. Its people like you that feel your special that ruin it for all of us. If you don't care enough about anyone else's opinion of our sport, then do us a favor and take that "beater bike" to the scrap yard and take up another hobby. Your not gonna find someone on here that shares your belief unless it some snot nose kid that apparently like yourself doesn't have the common courtesy for others and their property. Loud pipes DO get our areas shut down.

Its quite obvious you already had your mind made up that it was a good idea to put some idiotic obnoxiously loud fart pipe on your beater quad before you came on here and now your getting your feelings hurt because others don't share your opinion.... Sorry, your not going to change my belief on the subject and you'll find few others that will disagree.


nah i dont get it
loud pipes saves lives *****

[Flynbryan19]

Originally posted by 400exrider26400
nah i dont get it
loud pipes saves lives *****

On a street bike......perhaps...... and I leave that as a very sceptical "perhaps", but we're not talking about street bikes are we? We're talking about atvs. I'm curious. How exactly do you justify the old worn out tired "loud pipes save lives" excuse for an atv? You are after all riding in the woods right? And since "no one cares" you MUST be riding it out in the middle of no where all alone with no one around you for hundreds of miles right? So, what exactly at that point is your obnoxious fart can straight header doing for ya? Try a better arguement son.

[usp4u]

Originally posted by 400exrider26400
when did i say loud equals fast ?
im only running straight cus it sounds good .
lots of power lost but better loud than quiet

and whats the ****ing chance of starting a fire

I'm sure it sounds REALLY good. :rolleyes:
Please explain your thought process: "Lots of power lost but better loud than quiet"
So, let's KNOWINGLY give up performance to look/sound like a douchebag. It's no f-ing wonder the dirt bike crowd hates us.
You may think noone cares, but someone does. Your fellow riders. And about that fire thing...Have you ever volunteered to help the forestry service maintain/clean-up trails ? Go talk to some those boys, it does happen.

[timmersam]

Lets face it: straight pipe not only looks stupid it sounds awful. I don't care where you ride,you will piss someone off. Not to mention what running a straight pipe can do to your valves...

Sam

[storms400ex]

one word (INBREED)

[ALAMX37]

Do whatever you want man. Its a free country. Without the back pressure you get from a silencer you will lose performance. I have seen a 400 wiith redneck truck tips and no silencer and it wasnt as loud as my bike with the TC shorty. And no it wont sound good, pretty awkward, but hey if thats what you like go for it.

[quadboy-55]

you really are full of youreself arent you. i bet your even senseless enough not to even bother with a helmet.

[400exrider26400]

Originally posted by quadboy-55
you really are full of youreself arent you. i bet your even senseless enough not to even bother with a helmet.


wtf is your problem man i only asked if anybody was running straight pipe on there atvs

[storms400ex]

INBREED

[aDviSol2y]

Originally posted by storms400ex
INBREED


HAHAHAHAHAHA!

[quadboy-55]

Originally posted by 400exrider26400
wtf is your problem man i only asked if anybody was running straight pipe on there atvs

everyone keeps telling you to F*** the straight pipe idea, and you dont have the common sense to understand wtf you are doing to youre quad and the sport. ppl like that are the same ppl that think there above the the law and everyone else so they dont even need a helmet. im just saying, doenst mean you are, it just sounds like you think you are better than everyone else to do the stupedest things.

if you want it to sound good buy an aftermarket spark arrested muffler with a reonable sound rating.

not to mention with out a can on youre bike you are blowing heat and CO2 onto youre airbox. #1, hot air looses performance, the colder the better, #2, CO2 doesnt burn, CO2 in youre engine will rob you of power, and not to mention it does build up and make youre filter dirtier faster. #3, lie already posted, no back pressure, makes no power. ESPECALLY in a two stroke. bad jetting with removing the can can cause really lean or really rich running, and will deffinatly shorten the life of youre engine, more than it already is. sideeffects fo bad jetting also include scouring, and meliting pistons, but like you said, its a piss bike. so go throw a match down the gastank and burn the quad before it sets the forest on fire. atleast in the comfort of youre own home you have access to water to put it out.

[400exrider26400]

Originally posted by quadboy-55
everyone keeps telling you to F*** the straight pipe idea, and you dont have the common sense to understand wtf you are doing to youre quad and the sport. ppl like that are the same ppl that think there above the the law and everyone else so they dont even need a helmet. im just saying, doenst mean you are, it just sounds like you think you are better than everyone else to do the stupedest things.

if you want it to sound good buy an aftermarket spark arrested muffler with a reonable sound rating.

not to mention with out a can on youre bike you are blowing heat and CO2 onto youre airbox. #1, hot air looses performance, the colder the better, #2, CO2 doesnt burn, CO2 in youre engine will rob you of power, and not to mention it does build up and make youre filter dirtier faster. #3, lie already posted, no back pressure, makes no power. ESPECALLY in a two stroke. bad jetting with removing the can can cause really lean or really rich running, and will deffinatly shorten the life of youre engine, more than it already is. sideeffects fo bad jetting also include scouring, and meliting pistons, but like you said, its a piss bike. so go throw a match down the gastank and burn the quad before it sets the forest on fire. atleast in the comfort of youre own home you have access to water to put it out.


lmao funny dude

[quadboy-55]

Originally posted by 400exrider26400
lmao funny dude

i know, thats what everyone is saying anyways. might aswell listen to it.

[Toadz400]

Quadboy, he said LT230, those were 4-strokes.

400exrider26400, to answer your question: No, no one here is running straight pipes.

Honestly people, attacking him with insults and profanity is not going to change his mind. It is only going to further worsen the situation by giving him power over you. He knows what he's doing is going to anger all of you. If he happened to not care about our ATV community he could now use this against us by riding around on a straight piped LT230 and eventually he will come across an environmentalists who hates us all.

Obviously we all greatly disagree with straight pipes. So let us politely tell him why we believe straight pipes are not the smartest thing to do and that no, they are not cool on an ATV that is being ridden on the trails.

400exrider, you run a high risk of starting a forest fire because a straight pipe has no baffling or spark arrest to stop a spark/flame from exiting the pipe. You may not know it but internal combustion engines will throw sparks/flames out very often when not properly tuned. Chances are since this is your beater quad you will not have it tuned correctly for the straight pipe which will further increase the chances of fire. Please, if you have any respect for the sport and keeping it alive, do not put straight pipes on an ATV that you will be using on your trails. It doesn't matter if you are the only one using the trails, it just isn't safe or smart. It is perfectly fine/cool to put straight pipes on it if you just have the thing to show off to your friends in your yard. Leave it at that please. Thank you.

[400exrider26400]

Originally posted by Toadz400
Quadboy, he said LT230, those were 4-strokes.

400exrider26400, to answer your question: No, no one here is running straight pipes.

Honestly people, attacking him with insults and profanity is not going to change his mind. It is only going to further worsen the situation by giving him power over you. He knows what he's doing is going to anger all of you. If he happened to not care about our ATV community he could now use this against us by riding around on a straight piped LT230 and eventually he will come across an environmentalists who hates us all.

Obviously we all greatly disagree with straight pipes. So let us politely tell him why we believe straight pipes are not the smartest thing to do and that no, they are not cool on an ATV that is being ridden on the trails.

400exrider, you run a high risk of starting a forest fire because a straight pipe has no baffling or spark arrest to stop a spark/flame from exiting the pipe. You may not know it but internal combustion engines will throw sparks/flames out very often when not properly tuned. Chances are since this is your beater quad you will not have it tuned correctly for the straight pipe which will further increase the chances of fire. Please, if you have any respect for the sport and keeping it alive, do not put straight pipes on an ATV that you will be using on your trails. It doesn't matter if you are the only one using the trails, it just isn't safe or smart. It is perfectly fine/cool to put straight pipes on it if you just have the thing to show off to your friends in your yard. Leave it at that please. Thank you.



nvm the straight pipe
it has a supertrapp exhaust on now.........

but i still like the sound of straight pipe better

[pro-rider46]

holy crap, i totally agree with toadz400, i normally dont post when arguements are happening. but seriously, did you guys all have a bad day, and have a craving to start up a bash fest. Atleast do something productive instead of doing making yourself look like a Idiot over the internet.

okay, for a woodsmobile, a straight pipe is not very appropiate based on the risks. drag races, or something of that nature, its fair game. to straighten up some facts, a straight pipe will not destroy valves, it doesnt have much back pressure, which isnt good for performance, but doesnt damage engine parts when properly tuned on a 4 stroke. two strokes can run fine without a silencer too, as long as the header has a expansion chamber. if it doesnt. then it will not run properly. i have a ron woods drag pipe on my 450r, it has no packing what so ever, and i know everyone is going to argue this, but it has plenty of back pressure based on the design of the pipe, and it was a very noticable gain over my sparks pipe. loud as $h!T tho, not what im after, but it had worthy gains.

[quadboy-55]

i agree with toadz400. i was getting a little to worked up for a bash fest, LOL.

[John451]

I made a straight pipe for my old 300ex and it sounded awesome, it wasn't really a straight pipe but I made a can with rings to add backpresssure. The thing gained **** loads of power and sounded exactly like my friend's hmf pipe.The noise it put out was stupid. I switched back to my fmf right after trying it out for about 5 mins. But on a quad you have to have some noise coming out of it IMO because it makes it more fun. Not having a pipe is rediculous though unless you use it for drag racing.

[Ryanwolfe911]

I HATE loud exhausts, I don't care what they are. I'm actually quite frusterated because I can't find a quiet aftermarket pipe.

They're all loud as ****, even the ones that claim to have a "Quiet Core"

Someone needs to figure out how to engineer a high flow exhaust that's as quiet or quieter than the factory system.

[400exrider26400]

Originally posted by Ryanwolfe911
I HATE loud exhausts, I don't care what they are. I'm actually quite frusterated because I can't find a quiet aftermarket pipe.

They're all loud as ****, even the ones that claim to have a "Quiet Core"

Someone needs to figure out how to engineer a high flow exhaust that's as quiet or quieter than the factory system.


lmao it will never happen
to have a good performence exhaust you need alot of air flow and that equals loud.

[BlaineKaiser450]

My Joe Byrd Edition Dasa is 97 or 98 DB. And its about the same power as a normal Dasa, so i think thats the way to go, for mx at least. The only time i could see a straight pipe being worth it is on a fully built drag bike making 75HP thats only ridden at the strip

[John451]

Originally posted by 400exrider26400
lmao it will never happen
to have a good performence exhaust you need alot of air flow and that equals loud.

Unless they make one exactly like the 400ex one except about 5 feet long and 2 feet wide

[motofreak2772]

Originally posted by Ryanwolfe911
I HATE loud exhausts, I don't care what they are. I'm actually quite frusterated because I can't find a quiet aftermarket pipe.

They're all loud as ****, even the ones that claim to have a "Quiet Core"

Someone needs to figure out how to engineer a high flow exhaust that's as quiet or quieter than the factory system.
I think there should be one out there like that. I seen in a magazine an exhaust with two chambers in the silencer. I thought it was fmf but its not on their site. So thats new technology in making exhausts quieter.
That with a quiet core and maybe something like the dasa joe byrd header could make a really quiet exhaust.

[quadboy-55]

according to quad magazine they are working on a quiet edition SR-4 from motoworks.

[quadbod]

The "Doma Whisper" Exhaust System is 94db, much quieter than any stock pipe and produces good gains. Most of the top euro riders use them.

[John451]

Originally posted by quadbod
The "Doma Whisper" Exhaust System is 94db, much quieter than any stock pipe and produces good gains. Most of the top euro riders use them.

I'm guessing you've never heard a stock 400ex or trx450 the 450 is the quietest quad I've ever heard, it's quieter than my neighbor's honda rancher. And the 400ex is pretty quiet when it's new and not full of carbon and exhaust. You can hear the valves opening and closing on the 400ex. I'd be suprised if they put out more than 80db

[Ryanwolfe911]

ANd that's exactly what I'm talking about. I dont' have very close neighbors, but they are within earshot of me, and they're old and pissy. I don't like to upset them, cause they have done nice things for me.

I would absolutley love to have an exhaust no louder than a car, but still make somewhat of a performance gain. Actually I don't really care much about that. As long as i can still ride it, i'm doing just fine.

[Toadz400]

Ryan, there was an exhaust made called the Pulse Charger that used expansion chambers similar to a 2-stroke pipe and seemed quiet compared to most aftermarket pipes while making good gains in power. I'm not sure if it's still around or not. It sounds like you don't need an aftermarket exhaust. There are ways to make more power without going through the exhaust but you will never reach that full potential. Although for just a recreational machine it shouldn't be that big of a deal for you.

400exrider26400, you laugh at the idea but it is possible to create a free-flowing exhaust that is also quiet. Look at all the high performance vehicles out there coming from the factory with quiet exhausts. They don't need 130db exhausts to create power. All it takes is engineering and money.

[John451]

true, and you can even supercharge a car with a stock exhaust athough noone say's that they're high performance exhausts on the cars. They usually just put quiet exhausts that are very restrictive with fairly high flow air filters so the mpg number is high.

Originally posted by 400exrider26400
anyone running straight pipe on there atv ?

Depends on what you mean by straight pipe. What I do to all my exhausts is replace the exhaust core with a pipe. Exhaust cores have many holes in them so the sound can go threw and hit the packing to quiet the exhaust. If you replace the core with a pipe with no holes then no sound can get to the packing making the quad loud as running no muffler but you keep the same power you had and sound better than running no muffler.

Like this. The exhaust core was 1.75 so I replaced it with a 1.75 pipe so I kept the same power and went from about 101dbs to CRAZY LOUD!

Straight pipe in place of core. (normal core laying next to it)
http://i224.photobucket.com/albums/dd127/blue450yo/dum/Las-vegas2-09031.jpg

Looking inside end cap with straight pipe inplace of exhaust core.
http://i224.photobucket.com/albums/dd127/blue450yo/quad/l_ac3e3a9185f84221820f1a92989a9d5c.jpg

finished
http://i224.photobucket.com/albums/dd127/blue450yo/dum/Las-vegas2-09033.jpg

[400exrider26400]

Originally posted by spastic450
Depends on what you mean by straight pipe. What I do to all my exhausts is replace the exhaust core with a pipe. Exhaust cores have many holes in them so the sound can go threw and hit the packing to quiet the exhaust. If you replace the core with a pipe with no holes then no sound can get to the packing making the quad loud as running no muffler but you keep the same power you had and sound better than running no muffler.

Like this. The exhaust core was 1.75 so I replaced it with a 1.75 pipe so I kept the same power and went from about 101dbs to CRAZY LOUD!

Straight pipe in place of core. (normal core laying next to it)
http://i224.photobucket.com/albums/dd127/blue450yo/dum/Las-vegas2-09031.jpg

Looking inside end cap with straight pipe inplace of exhaust core.
http://i224.photobucket.com/albums/dd127/blue450yo/quad/l_ac3e3a9185f84221820f1a92989a9d5c.jpg

finished
http://i224.photobucket.com/albums/dd127/blue450yo/dum/Las-vegas2-09033.jpg


got any vid of it ?

[Toadz400]

spastic I like the flex pipe.:D

Is there a reason why you do this on all your machines?

Originally posted by Toadz400
spastic I like the flex pipe.:D

Is there a reason why you do this on all your machines?

No I just like loud and the way I do it keeps the power and produces a much better sound than just running no muffler or no packing. The pipe causes less restriction over the normal core but not enough to help any. I use flex pipe because its the thinnest pipe I can find.

Originally posted by 400exrider26400
got any vid of it ?

No but it sounds pretty much like how the exhaust did before I mest with it other than the sound being way amplified kind of like a radio have a song on low and then turn it up full blast. Same song just a lot louder.

[atv fan 28]

some people will never get it loud atv's = less riding areas!!

[storms400ex]

^^^^^ X2 on that

[Ryanwolfe911]

Jesus christ. Way to ruin a good exhaust system.

Originally posted by atv fan 28
some people will never get it loud atv's = less riding areas!!

People say that but never around here in my life has a trail system ever been shut down from noise. Only trails ever shut down around here were from people rutting up the trails with there quads. And where I ride is on a pipe line where there's always open header mud trucks out there and no houses for miles so noise don't matter.

Originally posted by Ryanwolfe911
Jesus christ. Way to ruin a good exhaust system.

Im pretty sure it's not ruining an exhaust when I technical gained performance threw out the whole power band from a slight decrease in back pressure.

[Toadz400]

It really comes down to every situation as far as loud = shut down riding areas. If he's got his own private land to ride on or an area that is clear of residences or businesses and is a common stomping ground for loud machines, then I say let him be loud.

It is also true that most trails are shut down from riding off the trails damaging the forest. Also general disrespect from riders is a major cause too.

[400exrider26400]

Originally posted by atv fan 28
some people will never get it loud atv's = less riding areas!!

juste ride in the woods then

[Toadz400]

Originally posted by 400exrider26400
juste ride in the woods then

It doesn't matter what the riding area is, if there are people around that do not like ATVs or loud noises then there will be problems.

[400exrider26400]

Originally posted by Toadz400
It doesn't matter what the riding area is, if there are people around that do not like ATVs or loud noises then there will be problems.

ITS IN THE ****ING WOODS WHERE THERES NO ONE FOR MILES

[storms400ex]

WILL A MODERATOR PLEASE LOCK THIS THREAD!!!!!!!

[400exrider26400]

Originally posted by storms400ex
WILL A MODERATOR PLEASE LOCK THIS THREAD!!!!!!!

why?

[450rJam]

louder does not equal better sound

you can crank the volume on a stock sterio system and have it loud but it sounds like crap compaired to an aftermarket system with good tone and base at the same db level

straight pipes on quads sound like raspy @ss compaired to an aftermarket with a good tone

and it screams look at me, I'm a newb/squid who needs to learn a thing or two

[atv fan 28]

exactly what i was thinkin!!! when i was 14 i wanted the loudest pipe there was, but now i look back and think how stupid i was!!

[Toadz400]

Originally posted by 400exrider26400
ITS IN THE ****ING WOODS WHERE THERES NO ONE FOR MILES

Notice I said IF there are people around. If you're on your own private land in the middle of nowhere, go ahead and be as loud as you want.

storms, why the sudden outburst?

[storms400ex]

no outburst just this thread is a waste cause he's going straight pipe and wont listen to no one so why not just lock it, loud pipes close trails and he dont care so just lock it and be done:D

Originally posted by storms400ex
no outburst just this thread is a waste cause he's going straight pipe and wont listen to no one so why not just lock it, loud pipes close trails and he dont care so just lock it and be done:D

Ya you think so? You know them quiet 96db pipes? 96db will be complained about the same amount as the 130db pipes. Some one who complains about nose is going to consider 96db as loud also. And you think noise shuts trails down? Like in my area only thing shutting trails down is spinning tires. Next time you trail ride remember the speed limit is 25 because speed will kill sound will not.

And closing this thread would be stupid. Because its loud? Theres no law about noise on peoples own land (in most places). What about next time some one posts how they wrecked there quad trail riding? Going to ask for thread to be closed because they where speeding over 25mph on the trail risking other people's lives?

Threads like this that get closed only make idiots more stupid. They don't get to hear why not to run no muffler so they just go and run no muffler then. Then they have valve or piston or rod or crank trouble and what do they post? They say not enough back pressure from no muffler blew there engine which is not only 100% wrong but it makes all other idiots think taking away a little back pressure or a muffler will wreck the engine when what really happens is they run lean which the heat is what causes the engine troubles because they didn't adj to get the right air fuel ratio but they end up telling people running no muffler or lack of back pressure wrecked there engine! And then there's the idiots thinking the header can suck cold air threw the header into the engine warping the valves when it cant happen and not to point out the fact that the engine is sucking cold air from the out side past the intake valves none stop and there fine!

And as for the straight pipe sound no one knows what it sounds like because it could be open header or a pipe at the end of the header or no packing or like my set up which is the #1 best way and best sounding to get loud. To me my set up sounds a lot like a dasa idling and till around 7000rpm then after its just loud as hell.

Originally posted by 450rJam
louder does not equal better sound

you can crank the volume on a stock sterio system and have it loud but it sounds like crap compaired to an aftermarket system with good tone and base at the same db level

straight pipes on quads sound like raspy @ss compaired to an aftermarket with a good tone

and it screams look at me, I'm a newb/squid who needs to learn a thing or two

You think they sound raspy when straight pipe could be 10 differant things. The term straight pipe is used way to often.

[storms400ex]

please lock this thread!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[400exrider26400]

Originally posted by storms400ex
please lock this thread!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

WHY?!?!?!

[450rJam]

you know you can "unsubscribe" to this thread and you have the option to NOT click on the post

and yet you still reply to close ???


a straight pipe to me is removing the muffler so the exhaust comes "straight" out the header or putting a "straight" pipe in place of the muffler (pretty much omiting the silencer)

[dns1764]

who gives a flying f***. he's a canadian. they're not even a real country. wow one person might hear him and b**** about it. who cares. let the canadian do as he pleases

[Toadz400]

How about everyone calms down?

[John451]

Originally posted by dns1764
who gives a flying f***. he's a canadian. they're not even a real country. wow one person might hear him and b**** about it. who cares. let the canadian do as he pleases

/\/\/\/\ HAAAAAAH True that

400exrider26400 ill send you a vid. Its not to good of one because it dont record sound the best but you can tell how crazy loud it is.

[atv fan 28]

make sure you turn the volume down on that video 400exrider26400! you dont wont his CRAZY LOUD exhaust to blow your computer speakers!

Originally posted by atv fan 28
make sure you turn the volume down on that video 400exrider26400! you dont wont his CRAZY LOUD exhaust to blow your computer speakers!

Won't blow the speakers out but will blow your ears out in person. This is a crap video because it's a cheep $100 camera that can record vids but trying to catch exhaust sound is bad and at the end you here a kid say how his ears hurt, which real ear pain can only happen after 125dbs and this exhaust is over 130dbs. With in a week or two I hope to get a vid of me riding so it can record a more accurate sound which will still not sound how it really does because the cam is cheep but you can see in this vid out loud it is. If you ever hit rev limiter with no muffler then you know how loud it is but this sounds much better, but not with this cam. A friend might use a real camcorder this weekend to catch the real sound. When I give it a little throttle for a few secs in about mid vid thats just a hair over idling and that shows how loud it is at that low of rpm! Top rpm cam cant really even catch a real quad sound from it being so loud and such a cheep cam. And its idiots with the cam. For the most real sound put head phones on.

http://i224.photobucket.com/albums/dd127/blue450yo/quad/th_88888.jpg (http://s224.photobucket.com/albums/dd127/blue450yo/quad/?action=view&current=88888.flv)

And this has nothing at all to do with my exhaust since all I did was make it louder and thats all but heres what people need to know since most people like to talk the word backpressure when they dont know any thing about what it is since the word loud and back pressure normaly come up in the same sentance.


ENGINE BACKPRESSURE: The myth and why it's wrong.

I. Introduction
One of the most misunderstood concepts in exhaust theory is backpressure. People love to talk about backpressure with no real understanding of what it is and what it's consequences are. I'm sure many of you have heard or read the phrase "Engines need backpressure" when discussing exhaust upgrades. That phrase is in fact completely inaccurate and a wholly misguided notion.

II. Some basic exhaust theory
Your exhaust system is designed to evacuate gases from the combustion chamber quickly and efficently. Exhaust gases are not produced in a smooth stream; exhaust gases originate in pulses. A 4 cylinder motor will have 4 distinct pulses per complete engine cycle, a 6 cylinder has 6 pules and so on. The more pulses that are produced, the more continuous the exhaust flow. Backpressure can be loosely defined as the resistance to positive flow - in this case, the resistance to positive flow of the exhaust stream.

III. Backpressure and velocity
Some people operate under the misguided notion that wider pipes are more effective at clearing the combustion chamber than narrower pipes. It's not hard to see how this misconception is appealing - wider pipes have the capability to flow more than narrower pipes. So if they have the ability to flow more, why isn't "wider is better" a good rule of thumb for exhaust upgrading? In a word - VELOCITY. I'm sure that all of you have at one time used a garden hose w/o a spray nozzle on it. If you let the water just run unrestricted out of the house it flows at a rather slow rate. However, if you take your finger and cover part of the opening, the water will flow out at a much much faster rate.

The astute exhaust designer knows that you must balance flow capacity with velocity. You want the exhaust gases to exit the chamber and speed along at the highest velocity possible - you want a FAST exhaust stream. If you have two exhaust pulses of equal volume, one in a 2" pipe and one in a 3" pipe, the pulse in the 2" pipe will be traveling considerably FASTER than the pulse in the 3" pipe. While it is true that the narrower the pipe, the higher the velocity of the exiting gases, you want make sure the pipe is wide enough so that there is as little backpressure as possible while maintaining suitable exhaust gas velocity. Backpressure in it's most extreme form can lead to reversion of the exhaust stream - that is to say the exhaust flows backwards, which is not good. The trick is to have a pipe that that is as narrow as possible while having as close to zero backpressure as possible at the RPM range you want your power band to be located at. Exhaust pipe diameters are best suited to a particular RPM range. A smaller pipe diameter will produce higher exhaust velocities at a lower RPM but create unacceptably high amounts of backpressure at high rpm. Thus if your powerband is located 2-3000 RPM you'd want a narrower pipe than if your powerband is located at 8-9000RPM.

Many engineers try to work around the RPM specific nature of pipe diameters by using setups that are capable of creating a similar effect as a change in pipe diameter on the fly. The most advanced is Ferrari's which consists of two exhaust paths after the header - at low RPM only one path is open to maintain exhaust velocity, but as RPM climbs and exhaust volume increases, the second path is opened to curb backpressure - since there is greater exhaust volume there is no loss in flow velocity. BMW and Nissan use a simpler and less effective method - there is a single exhaust path to the muffler; the muffler has two paths; one path is closed at low RPM but both are open at high RPM.

IV. So how did this myth come to be?
I often wonder how the myth "Engines need backpressure" came to be. Mostly I believe it is a misunderstanding of what is going on with the exhaust stream as pipe diameters change. For instance, someone with a civic decides he's going to uprade his exhaust with a 3" diameter piping. Once it's installed the owner notices that he seems to have lost a good bit of power throughout the powerband. He makes the connections in the following manner: "My wider exhaust eliminated all backpressure but I lost power, therefore the motor must need some backpressure in order to make power." What he did not realize is that he killed off all his flow velocity by using such a ridiculously wide pipe. It would have been possible for him to achieve close to zero backpressure with a much narrower pipe - in that way he would not have lost all his flow velocity.

V. So why is exhaust velocity so important?
The faster an exhaust pulse moves, the better it can scavenge out all of the spent gasses during valve overlap. The guiding principles of exhaust pulse scavenging are a bit beyond the scope of this doc but the general idea is a fast moving pulse creates a low pressure area behind it. This low pressure area acts as a vacuum and draws along the air behind it. A similar example would be a vehicle traveling at a high rate of speed on a dusty road. There is a low pressure area immediately behind the moving vehicle - dust particles get sucked into this low pressure area causing it to collect on the back of the vehicle. This effect is most noticeable on vans and hatchbacks which tend to create large trailing low pressure areas - giving rise to the numerous "wash me please" messages written in the thickly collected dust on the rear door(s).

[400exrider26400]

Originally posted by spastic450
And this has nothing at all to do with my exhaust since all I did was make it louder and thats all but heres what people need to know since most people like to talk the word backpressure when they dont know any thing about what it is since the word loud and back pressure normaly come up in the same sentance.


ENGINE BACKPRESSURE: The myth and why it's wrong.

I. Introduction
One of the most misunderstood concepts in exhaust theory is backpressure. People love to talk about backpressure with no real understanding of what it is and what it's consequences are. I'm sure many of you have heard or read the phrase "Engines need backpressure" when discussing exhaust upgrades. That phrase is in fact completely inaccurate and a wholly misguided notion.

II. Some basic exhaust theory
Your exhaust system is designed to evacuate gases from the combustion chamber quickly and efficently. Exhaust gases are not produced in a smooth stream; exhaust gases originate in pulses. A 4 cylinder motor will have 4 distinct pulses per complete engine cycle, a 6 cylinder has 6 pules and so on. The more pulses that are produced, the more continuous the exhaust flow. Backpressure can be loosely defined as the resistance to positive flow - in this case, the resistance to positive flow of the exhaust stream.

III. Backpressure and velocity
Some people operate under the misguided notion that wider pipes are more effective at clearing the combustion chamber than narrower pipes. It's not hard to see how this misconception is appealing - wider pipes have the capability to flow more than narrower pipes. So if they have the ability to flow more, why isn't "wider is better" a good rule of thumb for exhaust upgrading? In a word - VELOCITY. I'm sure that all of you have at one time used a garden hose w/o a spray nozzle on it. If you let the water just run unrestricted out of the house it flows at a rather slow rate. However, if you take your finger and cover part of the opening, the water will flow out at a much much faster rate.

The astute exhaust designer knows that you must balance flow capacity with velocity. You want the exhaust gases to exit the chamber and speed along at the highest velocity possible - you want a FAST exhaust stream. If you have two exhaust pulses of equal volume, one in a 2" pipe and one in a 3" pipe, the pulse in the 2" pipe will be traveling considerably FASTER than the pulse in the 3" pipe. While it is true that the narrower the pipe, the higher the velocity of the exiting gases, you want make sure the pipe is wide enough so that there is as little backpressure as possible while maintaining suitable exhaust gas velocity. Backpressure in it's most extreme form can lead to reversion of the exhaust stream - that is to say the exhaust flows backwards, which is not good. The trick is to have a pipe that that is as narrow as possible while having as close to zero backpressure as possible at the RPM range you want your power band to be located at. Exhaust pipe diameters are best suited to a particular RPM range. A smaller pipe diameter will produce higher exhaust velocities at a lower RPM but create unacceptably high amounts of backpressure at high rpm. Thus if your powerband is located 2-3000 RPM you'd want a narrower pipe than if your powerband is located at 8-9000RPM.

Many engineers try to work around the RPM specific nature of pipe diameters by using setups that are capable of creating a similar effect as a change in pipe diameter on the fly. The most advanced is Ferrari's which consists of two exhaust paths after the header - at low RPM only one path is open to maintain exhaust velocity, but as RPM climbs and exhaust volume increases, the second path is opened to curb backpressure - since there is greater exhaust volume there is no loss in flow velocity. BMW and Nissan use a simpler and less effective method - there is a single exhaust path to the muffler; the muffler has two paths; one path is closed at low RPM but both are open at high RPM.

IV. So how did this myth come to be?
I often wonder how the myth "Engines need backpressure" came to be. Mostly I believe it is a misunderstanding of what is going on with the exhaust stream as pipe diameters change. For instance, someone with a civic decides he's going to uprade his exhaust with a 3" diameter piping. Once it's installed the owner notices that he seems to have lost a good bit of power throughout the powerband. He makes the connections in the following manner: "My wider exhaust eliminated all backpressure but I lost power, therefore the motor must need some backpressure in order to make power." What he did not realize is that he killed off all his flow velocity by using such a ridiculously wide pipe. It would have been possible for him to achieve close to zero backpressure with a much narrower pipe - in that way he would not have lost all his flow velocity.

V. So why is exhaust velocity so important?
The faster an exhaust pulse moves, the better it can scavenge out all of the spent gasses during valve overlap. The guiding principles of exhaust pulse scavenging are a bit beyond the scope of this doc but the general idea is a fast moving pulse creates a low pressure area behind it. This low pressure area acts as a vacuum and draws along the air behind it. A similar example would be a vehicle traveling at a high rate of speed on a dusty road. There is a low pressure area immediately behind the moving vehicle - dust particles get sucked into this low pressure area causing it to collect on the back of the vehicle. This effect is most noticeable on vans and hatchbacks which tend to create large trailing low pressure areas - giving rise to the numerous "wash me please" messages written in the thickly collected dust on the rear door(s).



amen to that.

[400exrider26400]

Originally posted by spastic450
Won't blow the speakers out but will blow your ears out in person. This is a crap video because it's a cheep $100 camera that can record vids but trying to catch exhaust sound is bad and at the end you here a kid say how his ears hurt, which real ear pain can only happen after 125dbs and this exhaust is over 130dbs. With in a week or two I hope to get a vid of me riding so it can record a more accurate sound which will still not sound how it really does because the cam is cheep but you can see in this vid out loud it is. If you ever hit rev limiter with no muffler then you know how loud it is but this sounds much better, but not with this cam. A friend might use a real camcorder this weekend to catch the real sound. When I give it a little throttle for a few secs in about mid vid thats just a hair over idling and that shows how loud it is at that low of rpm! Top rpm cam cant really even catch a real quad sound from it being so loud and such a cheep cam. And its idiots with the cam. For the most real sound put head phones on.

http://i224.photobucket.com/albums/dd127/blue450yo/quad/th_88888.jpg (http://s224.photobucket.com/albums/dd127/blue450yo/quad/?action=view&current=88888.flv)


man that thing sounds mean:eek2:

[atv fan 28]

Originally posted by spastic450
And this has nothing at all to do with my exhaust since all I did was make it louder and thats all but heres what people need to know since most people like to talk the word backpressure when they dont know any thing about what it is since the word loud and back pressure normaly come up in the same sentance.


ENGINE BACKPRESSURE: The myth and why it's wrong.

I. Introduction
One of the most misunderstood concepts in exhaust theory is backpressure. People love to talk about backpressure with no real understanding of what it is and what it's consequences are. I'm sure many of you have heard or read the phrase "Engines need backpressure" when discussing exhaust upgrades. That phrase is in fact completely inaccurate and a wholly misguided notion.

II. Some basic exhaust theory
Your exhaust system is designed to evacuate gases from the combustion chamber quickly and efficently. Exhaust gases are not produced in a smooth stream; exhaust gases originate in pulses. A 4 cylinder motor will have 4 distinct pulses per complete engine cycle, a 6 cylinder has 6 pules and so on. The more pulses that are produced, the more continuous the exhaust flow. Backpressure can be loosely defined as the resistance to positive flow - in this case, the resistance to positive flow of the exhaust stream.

III. Backpressure and velocity
Some people operate under the misguided notion that wider pipes are more effective at clearing the combustion chamber than narrower pipes. It's not hard to see how this misconception is appealing - wider pipes have the capability to flow more than narrower pipes. So if they have the ability to flow more, why isn't "wider is better" a good rule of thumb for exhaust upgrading? In a word - VELOCITY. I'm sure that all of you have at one time used a garden hose w/o a spray nozzle on it. If you let the water just run unrestricted out of the house it flows at a rather slow rate. However, if you take your finger and cover part of the opening, the water will flow out at a much much faster rate.

The astute exhaust designer knows that you must balance flow capacity with velocity. You want the exhaust gases to exit the chamber and speed along at the highest velocity possible - you want a FAST exhaust stream. If you have two exhaust pulses of equal volume, one in a 2" pipe and one in a 3" pipe, the pulse in the 2" pipe will be traveling considerably FASTER than the pulse in the 3" pipe. While it is true that the narrower the pipe, the higher the velocity of the exiting gases, you want make sure the pipe is wide enough so that there is as little backpressure as possible while maintaining suitable exhaust gas velocity. Backpressure in it's most extreme form can lead to reversion of the exhaust stream - that is to say the exhaust flows backwards, which is not good. The trick is to have a pipe that that is as narrow as possible while having as close to zero backpressure as possible at the RPM range you want your power band to be located at. Exhaust pipe diameters are best suited to a particular RPM range. A smaller pipe diameter will produce higher exhaust velocities at a lower RPM but create unacceptably high amounts of backpressure at high rpm. Thus if your powerband is located 2-3000 RPM you'd want a narrower pipe than if your powerband is located at 8-9000RPM.

Many engineers try to work around the RPM specific nature of pipe diameters by using setups that are capable of creating a similar effect as a change in pipe diameter on the fly. The most advanced is Ferrari's which consists of two exhaust paths after the header - at low RPM only one path is open to maintain exhaust velocity, but as RPM climbs and exhaust volume increases, the second path is opened to curb backpressure - since there is greater exhaust volume there is no loss in flow velocity. BMW and Nissan use a simpler and less effective method - there is a single exhaust path to the muffler; the muffler has two paths; one path is closed at low RPM but both are open at high RPM.

IV. So how did this myth come to be?
I often wonder how the myth "Engines need backpressure" came to be. Mostly I believe it is a misunderstanding of what is going on with the exhaust stream as pipe diameters change. For instance, someone with a civic decides he's going to uprade his exhaust with a 3" diameter piping. Once it's installed the owner notices that he seems to have lost a good bit of power throughout the powerband. He makes the connections in the following manner: "My wider exhaust eliminated all backpressure but I lost power, therefore the motor must need some backpressure in order to make power." What he did not realize is that he killed off all his flow velocity by using such a ridiculously wide pipe. It would have been possible for him to achieve close to zero backpressure with a much narrower pipe - in that way he would not have lost all his flow velocity.

V. So why is exhaust velocity so important?
The faster an exhaust pulse moves, the better it can scavenge out all of the spent gasses during valve overlap. The guiding principles of exhaust pulse scavenging are a bit beyond the scope of this doc but the general idea is a fast moving pulse creates a low pressure area behind it. This low pressure area acts as a vacuum and draws along the air behind it. A similar example would be a vehicle traveling at a high rate of speed on a dusty road. There is a low pressure area immediately behind the moving vehicle - dust particles get sucked into this low pressure area causing it to collect on the back of the vehicle. This effect is most noticeable on vans and hatchbacks which tend to create large trailing low pressure areas - giving rise to the numerous "wash me please" messages written in the thickly collected dust on the rear door(s). that was a nice copy and paste job! did you have your 450 next to a jet and compare DBs!

[450rJam]

its actually illegal to post someone elses info as your own

but as the document states there has to be volocity.......... which is created by choking the pipe size (like the restriction when putting your thumb over the garden hose)

the choking IS causing more resistance which in turn causes more pressure

this is all different from joe blow running a straight pipe for the obnoxious sound and NOT performance

[Ryanwolfe911]

I guess what it comes down to is who cares. If the OP wants to **** up his quad and look like and ******* in the process, then let him go ahead and do it.

Originally posted by Ryanwolfe911
I guess what it comes down to is who cares. If the OP wants to **** up his quad and look like and ******* in the process, then let him go ahead and do it.

He can not screw up his quad as long as he re-jets to get the right fuel/air ratio. Running lean hurts engines running loud does not. And some one telling some one who likes loud exhausts that they think its stupid to be loud will not stop some one from being or wanting to be loud. After all this thread was started and is about straight pipe exhausts and not peoples opinions or false knowledge.

Only real reason it's stupid to run open header or a pipe off the end of the header is because you will loose power even if jetted right. My way of straight pipe is the only real way that works and the fuel/air ratio does not change. Done any other way and power will go to crap and I know it for a fact because I once broke a muffler off on a jump and my bottom end power went to total crap.

[atv fan 28]

Originally posted by spastic450
He can not screw up his quad as long as he re-jets to get the right fuel/air ratio. Running lean hurts engines running loud does not. And some one telling some one who likes loud exhausts that they think its stupid to be loud will not stop some one from being or wanting to be loud. After all this thread was started and is about straight pipe exhausts and not peoples opinions or false knowledge.

Only real reason it's stupid to run open header or a pipe off the end of the header is because you will loose power even if jetted right. My way of straight pipe is the only real way that works and the fuel/air ratio does not change. Done any other way and power will go to crap and I know it for a fact because I once broke a muffler off on a jump and my bottom end power went to total crap. you should patented your exhaust method! you could make alot of money!

[John451]

All you who want to have straight pipes, I have a better idea.
STEP 1: Get a 4' piece of 1.5" flex tubing
STEP 2: Take exhaust off quad
STEP 3: Attach flex tubing to exhaust port
STEP 4: Drill hole in helmet next to ear
STEP 5: Attach other end of flex tubing to helmet
STEP 6: Start it up, crack the throttle, and enjoy.

Originally posted by atv fan 28
you should patented your exhaust method! you could make alot of money!

Haha I don't think so. Every exhaust manufacture already knows what I do and that's the reason they make cores only with holes and not cores with no holes. I could make universal 1.75/2.00/2.25 cores that need to be cut by owner to fit the length of there pipe but that wouldn't work out to good since half the exhausts out there have cores that are welded in Not all have removable/replaceable cores. Some comps sell other cores for there exhausts bigger or smaller cores to change the power for better lower or better top end power but they all come with holes because every comp knows with out the holes the sound can not get to the packing..

Originally posted by John451
All you who want to have straight pipes, I have a better idea.
STEP 1: Get a 4' piece of 1.5" flex tubing
STEP 2: Take exhaust off quad
STEP 3: Attach flex tubing to exhaust port
STEP 4: Drill hole in helmet next to ear
STEP 5: Attach other end of flex tubing to helmet
STEP 6: Start it up, crack the throttle, and enjoy.

I think it be cooler if the pipe went in the mouth.

[storms400ex]

i think they should kick you off again cause you are a idiot for having a loud piece of crap pipe, where you lose power, and go ask a person that drag races bikes they will tell you, you need back pressure!!!!!!!!!! please get rid of this guy again PLEASE

Originally posted by storms400ex
i think they should kick you off again cause you are a idiot for having a loud piece of crap pipe, where you lose power, and go ask a person that drag races bikes they will tell you, you need back pressure!!!!!!!!!! please get rid of this guy again PLEASE

Go a page or two back about backpressure. You do not need or want backpressure but you do want a exhaust for good performance. Trying to make some one not like loud is like trying to get some one to change there favroite color. Not going to happen.

[BakerRacing40]

back pressure helps scavenging.. the key to get power from an engine is to move air, velocity and back pressure have to work together to create power.....

Originally posted by BakerRacing40
back pressure helps scavenging.. the key to get power from an engine is to move air, velocity and back pressure have to work together to create power.....

No. Backpressure works against velocity = bad.


Backpressure 100% bad. Fast velocity #1 thing needed. Backpressure slows the exhaust flow/velocity.

Learn what backpressure is...

[BakerRacing40]

Originally posted by spastic450
No. Backpressure works against velocity = bad.


Backpressure 100% bad. Fast velocity #1 thing needed. Backpressure slows the exhaust flow/velocity.

Learn what backpressure is...


and your dumb... i just said back pressure helps scavenging. scavenging is good... scavenging helps pull air through an engine for a more efficient combustion cycle... that's why engines are designed to have valve overlap...
and if back pressure doesn't matter pull the complete exhaust system ( that includes the header/manifold) off your hyundai shoot some more fuel to it and see how far you get.

[450rJam]

he just read ONE document and interprets is as "anything called backpressure is bad"

less restriction (or back pressure) will kill torque (low end)

more restriction (less back pressure) will kill top end

you have to have a "happy spot"

if you think of your motor like a straw that air flows into and out of
you may understant that even if you double the size of the end of the straw (the rest remaining the same size) your NOT going to flow anymore air

this is why (for maximum performance) you need to improve intake, porting, valves, AND exhaust
(the whole straw) while maintaining fuel/air ratio

ps. the guy could save some flex pipe if he ran it under the seat and up his @$$

[quadbod]

Originally posted by spastic450
No. Backpressure works against velocity = bad.


Backpressure 100% bad. Fast velocity #1 thing needed. Backpressure slows the exhaust flow/velocity.

Learn what backpressure is...

Backpressure=good.

Noisey pipes= bad.


You=idiot.

[John451]

Originally posted by quadbod
Backpressure=good.

Noisey pipes= bad.


You=idiot.

Go stand with your crotch about 10 feet away from a dragbike or quad and tell me there's backpressure with your girl-ish voice from doing that. You can stand about 20 feet away and it'll still feel like sum1's punching your hand. They find and reach the equilibrium of backpressure and no backpressure to help the exhaust get out as quickly as possisble

[storms400ex]

if we didnt have to have back pressure then why would the companys make everything have back pressure, no back pressure will make your valves go out faster, and a 100 dollar cam dosnt mean nothing, this dude SPASTIC450 has been kicked off here alot, he is a idiot, and bull ****ter. loud and no backpressure = dumbass

[Toadz400]

Well this thread just proves to me that we can't act maturely and argue at the same time.

spastic - Instead of copying and pasting you should actually understand how an exhaust works.

The goal of a true performance exhaust system is to have the perfect balancing point of almost zero back pressure while still maintaining optimum exhaust scavenging. This is why two-strokes have expansion pipes which, put simply, is to allow some of the pressure waves to bounce back and help draw in the intake charge and expel the exhaust charge. They have even begun using this same concept on four-strokes because it still applies to them.

I didn't explain it worth crap but you can find tons and tons of information on it if you search correctly.

Well you cant fix stupid. I am no docter so go find some other thread or doc phill. Backpressure is the hardest thing to learn and with most people having no clue what it is they refuse to learn what it is. I don't try and teach people this for my self I do it to help others learn but cant teach some one who refuses to learn. Up is left and down is right. Any ways this thread is NOT about who likes loud this thread is about who runs straight pipes. Go put your self in a thread you can help. I am not going to keep trying to say how a "core" does not produce back pressure or change power as long as its the same size. If your stuck on thinking you are right then E-mail a exhaust comp and ask about cores, cores with holes and cores with no holes if thats what it will take to learn. Backpressure has nothing to do with what I did because it did not change backpressure or power its a CORE aka a pipe with not bends! If you wan to talk backpressure than make your own thread. This thread is not about what you"think" or your opinion it is about loud exhausts and so far im the only one that can help every one else is just spamming. Make your own threads.


Do you run straight pipe? If not do not post.

Originally posted by Toadz400
Well this thread just proves to me that we can't act maturely and argue at the same time.

spastic - Instead of copying and pasting you should actually understand how an exhaust works.

The goal of a true performance exhaust system is to have the perfect balancing point of almost zero back pressure while still maintaining optimum exhaust scavenging. This is why two-strokes have expansion pipes which, put simply, is to allow some of the pressure waves to bounce back and help draw in the intake charge and expel the exhaust charge. They have even begun using this same concept on four-strokes because it still applies to them.

I didn't explain it worth crap but you can find tons and tons of information on it if you search correctly.

No. 2 stroke and 4 stroke 100% not at all the same. 2 stroke power realys on backpresure/expansion chamber to push back the exhaust "gasses" thats why 2 strokes have expansion chambers and 4 strokes do not. And the old 2 strokes never had expansion chambers and what happen? They lacked power and used more gas. With a expansion chamber they make more power and use less gas because the extra gas shoots back into the cylinder as the piston goes back up. Trying to make up some idea 2 and 4 stroke exhaust work the same is 100% derrrr.

Do you think this is how a 4 stroke engine and exhaust works? Don't respond any ways this is about straight pipes not you I'm just helping show why you where wrong.
http://i31.photobucket.com/albums/c372/ben234/two-stroke_c.gif

[Toadz400]

Originally posted by spastic450
No. 2 stroke and 4 stroke 100% not at all the same. 2 stroke power realys on backpresure/expansion chamber to push back the exhaust "gasses" thats why 2 strokes have expansion chambers and 4 strokes do not. And the old 2 strokes never had expansion chambers and what happen? They lacked power and used more gas. With a expansion chamber they make more power and use less gas because the extra gas shoots back into the cylinder as the piston goes back up. Trying to make up some idea 2 and 4 stroke exhaust work the same is 100% derrrr.

Do you think this is how a 4 stroke engine and exhaust works? Don't respond any ways this is about straight pipes not you I'm just helping show why you where wrong.
http://i31.photobucket.com/albums/c372/ben234/two-stroke_c.gif

I did not say that two strokes and four strokes are the same. I said that expansion chambers also offer the same benefits for four strokes. Have you heard of valve overlap? It's part of the same concept allowing the exhaust to help draw in the intake charge allowing for more power and efficiency. Here's a quote from mechadyne-int.com:

" Control of valve overlap is a key factor in improving engine fuel economy and emissions. Valve overlap is the point near piston TDC in the 4-stroke cycle where both the intake and the exhaust valves are open at the same time.

At low speed, the effect of valve overlap is to re-introduce exhaust gasses into the combustion chamber. This is known as generating internal exhaust gas re-circulation or internal EGR. The benefits from internal EGR are two-fold:

Firstly, internal EGR benefits part load fuel economy by diluting the charge within the cylinder, thus restricting output without the need for increased throttling and its associated pumping losses.

Secondly, internal EGR also reduces hydrocarbon and NOX emissions by the re-circulation of un-burnt exhaust gasses. The retained exhaust gasses tend to be very rich in un-burnt Hydrocarbons, as they typically come from crevice volumes that are expelled at the end of the exhaust stroke. This strategy can therefore be quite effective at reducing emissions.

Variable valve timing can also be used to reduce the work required by the piston to pump the combustion gasses into and out of the combustion chamber. This may yield further fuel economy benefits. "

I can't even respond to anything you say because you are just looking to argue with people. I am not arguing with your straight pipe cores. I was commenting on the information that you copied and pasted from another site, of which you still have not given credit to.

[Toadz400]

Have you ever heard of FMF's Megabomb headers? Better call them up and tell them that they are WRONG and those pipes should only be used on two-strokes.

Here's a quote from a discussion on thumpertalk.com by a member who explains it quite well.

"grayracer513
01-14-2005, 08:27 PM
If you really found out what goes on with expansion chambers, you know it's a fairly complicated thing. Sonic-speed shock waves are timed to arrive just in time to stuff the fuel/air that escaped through the two-stroke's exhaust port back into the cylinder just before closing.

Four stroke exhausts can work in similar ways, but because the four-stroke is more like a positive pump, and not so dependent on the dynamics of gas inertia just to even run, the effect an exhaust system will have on them is going to be more subdued. And there have been "expansion chambers" built for four-strokes for years. They're called megaphones.

In very simplified form, first understand that the exhaust opens, then the intake opens, then the exhaust closes, then the intake closes. The period when they are both open is the valve overlap, and happens as the piston goes over top center at the end of the exhaust stroke. At this time, the piston has just finished shoving the exhaust out past the exhaust valve and is starting down, but because gas has inertia, some left over exhaust is still leaving, and we don't want to close the valve too soon. At the same time, back a bit before we got to top dead center, we opened the intake. The last time the intake was closed, we slammed the door on a column of moving air and fuel, and it piled up against the valve under the pressure of its own weight. Once a condition is reached where the remaining exhaust pressure is lower than that built up in the intake, we can open the intake without exhaust going back up into the intake. In fact, if we time things right, we can have the exhaust help the intake fill the cylinder.

When the exhaust opens, the gas flows out in a pulse, a wave of high pressure in front of the pulse, and a pocket of low pressure trailing behind. If we open the intake as this low pressure trailer is still in the cylinder, it makes it simpler to get the intake charge in.

But what can the exhaust system do? As a high pressure wave exits the pipe, or moves into a significantly larger section of it, it creates a wave of low pressure that starts back toward the exhaust valve. If that wave gets to the valve just before it closes it will help clear the last bit of exhaust from the cylinder, and that will help pull in the fresh charge. The timing and magnitude of this effect can be tailored by changing the length and configuration of the exhaust system.

Using reversing cones is intended to create pressure waves to do some other voodoo in the system. Exhaust builders are messing with some really interesting ideas now that I haven't seen any theory on, liked stepped pipes and the use of internal rings or small expansion chambers in the header, so it gets deeper. But a pipe isn't going to give a four-stroke the massive, off-ON-off kind of hit a two-stroke has, and really, you wouldn't want it to. That would change one of the big things that makes them better in the first place."

[Toadz400]

With that I'll leave this thread because I do not have a straight pipe on anything I own because it is simply not beneficial to optimum performance for the riding I do.

Just remember that each one of us represents all quad riders.

[steel1]

Originally posted by spastic450
And this has nothing at all to do with my exhaust since all I did was make it louder and thats all but heres what people need to know since most people like to talk the word backpressure when they dont know any thing about what it is since the word loud and back pressure normaly come up in the same sentance.


ENGINE BACKPRESSURE: The myth and why it's wrong.

I. Introduction
One of the most misunderstood concepts in exhaust theory is backpressure. People love to talk about backpressure with no real understanding of what it is and what it's consequences are. I'm sure many of you have heard or read the phrase "Engines need backpressure" when discussing exhaust upgrades. That phrase is in fact completely inaccurate and a wholly misguided notion.

II. Some basic exhaust theory
Your exhaust system is designed to evacuate gases from the combustion chamber quickly and efficently. Exhaust gases are not produced in a smooth stream; exhaust gases originate in pulses. A 4 cylinder motor will have 4 distinct pulses per complete engine cycle, a 6 cylinder has 6 pules and so on. The more pulses that are produced, the more continuous the exhaust flow. Backpressure can be loosely defined as the resistance to positive flow - in this case, the resistance to positive flow of the exhaust stream.

III. Backpressure and velocity
Some people operate under the misguided notion that wider pipes are more effective at clearing the combustion chamber than narrower pipes. It's not hard to see how this misconception is appealing - wider pipes have the capability to flow more than narrower pipes. So if they have the ability to flow more, why isn't "wider is better" a good rule of thumb for exhaust upgrading? In a word - VELOCITY. I'm sure that all of you have at one time used a garden hose w/o a spray nozzle on it. If you let the water just run unrestricted out of the house it flows at a rather slow rate. However, if you take your finger and cover part of the opening, the water will flow out at a much much faster rate.

The astute exhaust designer knows that you must balance flow capacity with velocity. You want the exhaust gases to exit the chamber and speed along at the highest velocity possible - you want a FAST exhaust stream. If you have two exhaust pulses of equal volume, one in a 2" pipe and one in a 3" pipe, the pulse in the 2" pipe will be traveling considerably FASTER than the pulse in the 3" pipe. While it is true that the narrower the pipe, the higher the velocity of the exiting gases, you want make sure the pipe is wide enough so that there is as little backpressure as possible while maintaining suitable exhaust gas velocity. Backpressure in it's most extreme form can lead to reversion of the exhaust stream - that is to say the exhaust flows backwards, which is not good. The trick is to have a pipe that that is as narrow as possible while having as close to zero backpressure as possible at the RPM range you want your power band to be located at. Exhaust pipe diameters are best suited to a particular RPM range. A smaller pipe diameter will produce higher exhaust velocities at a lower RPM but create unacceptably high amounts of backpressure at high rpm. Thus if your powerband is located 2-3000 RPM you'd want a narrower pipe than if your powerband is located at 8-9000RPM.

Many engineers try to work around the RPM specific nature of pipe diameters by using setups that are capable of creating a similar effect as a change in pipe diameter on the fly. The most advanced is Ferrari's which consists of two exhaust paths after the header - at low RPM only one path is open to maintain exhaust velocity, but as RPM climbs and exhaust volume increases, the second path is opened to curb backpressure - since there is greater exhaust volume there is no loss in flow velocity. BMW and Nissan use a simpler and less effective method - there is a single exhaust path to the muffler; the muffler has two paths; one path is closed at low RPM but both are open at high RPM.

IV. So how did this myth come to be?
I often wonder how the myth "Engines need backpressure" came to be. Mostly I believe it is a misunderstanding of what is going on with the exhaust stream as pipe diameters change. For instance, someone with a civic decides he's going to uprade his exhaust with a 3" diameter piping. Once it's installed the owner notices that he seems to have lost a good bit of power throughout the powerband. He makes the connections in the following manner: "My wider exhaust eliminated all backpressure but I lost power, therefore the motor must need some backpressure in order to make power." What he did not realize is that he killed off all his flow velocity by using such a ridiculously wide pipe. It would have been possible for him to achieve close to zero backpressure with a much narrower pipe - in that way he would not have lost all his flow velocity.

V. So why is exhaust velocity so important?
The faster an exhaust pulse moves, the better it can scavenge out all of the spent gasses during valve overlap. The guiding principles of exhaust pulse scavenging are a bit beyond the scope of this doc but the general idea is a fast moving pulse creates a low pressure area behind it. This low pressure area acts as a vacuum and draws along the air behind it. A similar example would be a vehicle traveling at a high rate of speed on a dusty road. There is a low pressure area immediately behind the moving vehicle - dust particles get sucked into this low pressure area causing it to collect on the back of the vehicle. This effect is most noticeable on vans and hatchbacks which tend to create large trailing low pressure areas - giving rise to the numerous "wash me please" messages written in the thickly collected dust on the rear door(s).


Hey man im worried about the whole back pressure thing too. I have a 08 suzuki 750 I did nt straight pipe it, but i made a custom pipe using a hintol strreet bike muffler. sounds wicked. I kept the stock 1 3/4 pipe from the motor, cut the old stock muffler off flared the pipe to fit the hintols 2 inch inlet. tig weled it up good to go

[400exrider26400]

Originally posted by steel1
Hey man im worried about the whole back pressure thing too. I have a 08 suzuki 750 I did nt straight pipe it, but i made a custom pipe using a hintol strreet bike muffler. sounds wicked. I kept the stock 1 3/4 pipe from the motor, cut the old stock muffler off flared the pipe to fit the hintols 2 inch inlet. tig weled it up good to go


must sound good :eek2:

[quadbod]

Originally posted by steel1
Hey man im worried about the whole back pressure thing too. I have a 08 suzuki 750 I did nt straight pipe it, but i made a custom pipe using a hintol strreet bike muffler. sounds wicked. I kept the stock 1 3/4 pipe from the motor, cut the old stock muffler off flared the pipe to fit the hintols 2 inch inlet. tig weled it up good to go

Pics?

[tayyo789]

ok. first off, spastic, take a physics class that has a section on sound waves and decibels. one thing you will learn is that the airplanes that you hear from 50 miles away are 130 decibels. the increment known as the decibel increases by a power of 10. therefore, each "decibel" is 10 times louder than the decibel before it. if your quad is truly 130 decibels, enjoy being deaf after 30 minutes of riding.
second, i would like to say that sound IS the largest factor in closing riding areas. at least where i live. i may only be 18, but i did my senior project on the closing of my local riding areas, and they were caused by the expanding residential zones being closer and closer to the areas where we ride, and peoples bikes being heard from the houses that were built for people who live where they do for the aspect of solitude. rutted trails are not a problem. the problem is riding off of designated trails and destroying wildlife and causing unwanted erosion.
but it sounds like you guys are riding where there isnt anybody EVER and you are riding with the same hearing protection offered to those that are employed at the airports that are MILES from your house.

[400exrider26400]

Originally posted by tayyo789
ok. first off, spastic, take a physics class that has a section on sound waves and decibels. one thing you will learn is that the airplanes that you hear from 50 miles away are 130 decibels. the increment known as the decibel increases by a power of 10. therefore, each "decibel" is 10 times louder than the decibel before it. if your quad is truly 130 decibels, enjoy being deaf after 30 minutes of riding.
second, i would like to say that sound IS the largest factor in closing riding areas. at least where i live. i may only be 18, but i did my senior project on the closing of my local riding areas, and they were caused by the expanding residential zones being closer and closer to the areas where we ride, and peoples bikes being heard from the houses that were built for people who live where they do for the aspect of solitude. rutted trails are not a problem. the problem is riding off of designated trails and destroying wildlife and causing unwanted erosion.
but it sounds like you guys are riding where there isnt anybody EVER and you are riding with the same hearing protection offered to those that are employed at the airports that are MILES from your house.



if you want a loud pipe go with the tc shorty :D

[xtreme 250x]

Sorry to say i watched Spastics video and that bike sounds like crap. It might be loud but its no Harley dude.

[tayyo789]

absolutely nowhere in my post did i mention wanting a loud pipe. pay attention to what your'e reading before you reply next time

[400exrider26400]

Originally posted by tayyo789
absolutely nowhere in my post did i mention wanting a loud pipe. pay attention to what your'e reading before you reply next time


oh and the second loudest is the curtis sparks

[tayyo789]

actually, according to this thread, the sparks pipe would be third. i personally think that exhausts like rossier and some lrd's are louder than any sparks ive heard. but since spastics is at 130db's, it takes the cake, followed by the shorty.

[kfx400rider03]

lol
there alot of post in this thread.
and its probaly a younger teenager(13-16yo) wanting to have something loud.
everyone here cant say they didnt want something to be a joke and loud at one point in there life....

[TNT]

Originally posted by kfx400rider03
lol
there alot of post in this thread.
and its probaly a younger teenager(13-16yo) wanting to have something loud.
everyone here cant say they didnt want something to be a joke and loud at one point in there life....

Pretty entertaining ehhh…lol!

Guy’s that had arguments for straight pipes were valid in the old days, these days they are less efficient becoming more so with quite cores. Todays technology uses pressure differentials which back pressure facilitates to produce higher speed exhaust velocities and intake pressures than straight pipes. The venturi tube (EG: reversing cones, divergent or converging duct), stepping pipes, and the combination at the right locations manipulates pressure and velocity (such as the megabomb) in such a manner that produce higher exhaust velocities than straight pipes. It’s been done for years in the turbine section of jet engines (the cone shape decreases pressure and increases velocity and visa-versa), no straight section of pipe alone will do this. There are all kinds of new sound cancellation techniques these days too.

Toadz400 had the best post on this thread that said it all……


Originally posted by Toadz400
Have you ever heard of FMF's Megabomb headers? Better call them up and tell them that they are WRONG and those pipes should only be used on two-strokes.

Here's a quote from a discussion on thumpertalk.com by a member who explains it quite well.

"grayracer513
01-14-2005, 08:27 PM
If you really found out what goes on with expansion chambers, you know it's a fairly complicated thing. Sonic-speed shock waves are timed to arrive just in time to stuff the fuel/air that escaped through the two-stroke's exhaust port back into the cylinder just before closing.

Four stroke exhausts can work in similar ways, but because the four-stroke is more like a positive pump, and not so dependent on the dynamics of gas inertia just to even run, the effect an exhaust system will have on them is going to be more subdued. And there have been "expansion chambers" built for four-strokes for years. They're called megaphones.

In very simplified form, first understand that the exhaust opens, then the intake opens, then the exhaust closes, then the intake closes. The period when they are both open is the valve overlap, and happens as the piston goes over top center at the end of the exhaust stroke. At this time, the piston has just finished shoving the exhaust out past the exhaust valve and is starting down, but because gas has inertia, some left over exhaust is still leaving, and we don't want to close the valve too soon. At the same time, back a bit before we got to top dead center, we opened the intake. The last time the intake was closed, we slammed the door on a column of moving air and fuel, and it piled up against the valve under the pressure of its own weight. Once a condition is reached where the remaining exhaust pressure is lower than that built up in the intake, we can open the intake without exhaust going back up into the intake. In fact, if we time things right, we can have the exhaust help the intake fill the cylinder.

When the exhaust opens, the gas flows out in a pulse, a wave of high pressure in front of the pulse, and a pocket of low pressure trailing behind. If we open the intake as this low pressure trailer is still in the cylinder, it makes it simpler to get the intake charge in.

But what can the exhaust system do? As a high pressure wave exits the pipe, or moves into a significantly larger section of it, it creates a wave of low pressure that starts back toward the exhaust valve. If that wave gets to the valve just before it closes it will help clear the last bit of exhaust from the cylinder, and that will help pull in the fresh charge. The timing and magnitude of this effect can be tailored by changing the length and configuration of the exhaust system.

[Using reversing cones is intended to create pressure waves to do some other voodoo in the system. Exhaust builders are messing with some really interesting ideas now that I haven't seen any theory on, liked stepped pipes and the use of internal rings or small expansion chambers in the header, so it gets deeper. But a pipe isn't going to give a four-stroke the massive, off-ON-off kind of hit a two-stroke has, and really, you wouldn't want it to. That would change one of the big things that makes them better in the first place." ."

[jdog75]

Originally posted by Flynbryan19
On a street bike......perhaps...... and I leave that as a very sceptical "perhaps", but we're not talking about street bikes are we? We're talking about atvs. I'm curious. How exactly do you justify the old worn out tired "loud pipes save lives" excuse for an atv? You are after all riding in the woods right? And since "no one cares" you MUST be riding it out in the middle of no where all alone with no one around you for hundreds of miles right? So, what exactly at that point is your obnoxious fart can straight header doing for ya? Try a better arguement son.

loud does = fast. the faster you lose money rebuilding your atv. my friend has an 07 300 ex and he needed the loudest pipe he could find, made it as loud as he could and since it was rebuilt twice luckily it was under warranty but i have a 2000 400 that was never rebuilt once in its near ten years of existince.

[jdog75]

Originally posted by Flynbryan19
On a street bike......perhaps...... and I leave that as a very sceptical "perhaps", but we're not talking about street bikes are we? We're talking about atvs. I'm curious. How exactly do you justify the old worn out tired "loud pipes save lives" excuse for an atv? You are after all riding in the woods right? And since "no one cares" you MUST be riding it out in the middle of no where all alone with no one around you for hundreds of miles right? So, what exactly at that point is your obnoxious fart can straight header doing for ya? Try a better arguement son.

loud does = fast. the faster you lose money rebuilding your atv. my friend has an 07 300 ex and he needed the loudest pipe he could find, made it as loud as he could and since it was rebuilt twice luckily it was under warranty but i have a 2000 400 that was never rebuilt once in its near ten years of existince.

[f4iracer]

hello all,

i just wanted to give my 2 cents.

First i don't think it would be right to ban the poster for creating this thread, at least he is just taking out all his madness in these posts.

This kid is not that far off. I know all you old farts don't likie noise and kids making noise, but the way he has the pipe setup is probably gonna get more power than any pipe u can buy.

I used to run race go karts when i was a little younger and those babies had straight up pipes

I'm talking pipes coming straight out the header and straight out the back.


blame my dad for the fabrication but he was also trying for the fastest karts.

[tayyo789]

Old farts? The age of a person does not determine their concern for keeping this sport from collapsing due to the ignorance of some "kid". I would bet you didnt read all the posts before this page, because if you did, then you would have seen all of the evidence proving that mufflers have a purpose, and in fact increase performance. Toadz400 said it perfectly. If you ARE correct, then you should go tell every exhaust manufacturer and tell them that all the work that they had done in the last 30 years is wasted, and wrong.

[f4iracer]

for more power you need less back pressure!



for the most part, the more back-pressure you eliminate the more power you'll get. (to a certain point, there is certainly a line there.) I think all of you need to check your stats. This kid is a squid no doubt about it, but he's got very good points about back pressure (as do many of you)....no matter how much you all hate straight pipes, u can draw lots of power out of less backpressure if you tune it.

do you know what kind of pipe is on a flat track race bike? take a harley 750tt flat track bike for example. It's a single cylinder motor, air cooled. Every one of those bikes, (90% of them are harleys) on the track is running a straight pipe!

They wouldn't run a straight pipe if they weren't looking for more power people.

[tayyo789]

The straight pipes you're referring to do exist, but that is flattracking, not riding in our diminishing recreational areas. Closed course racing is completely different than off road riding. Those bikes are run on a track, and in the garage. The exhausts on them appear to be "straight" but have slight differences in the circumferences of the inside and outside of the pipe. Slight expansion chambers if you will. When people put a "straight" pipe on them to increase performance, in a situation such as flattracking the riders are constantly either going full throttle, or not at all, as opposed to the full range of throttle positions.

[TNT]

Originally posted by f4iracer
for more power you need less back pressure!



for the most part, the more back-pressure you eliminate the more power you'll get. (to a certain point, there is certainly a line there.) I think all of you need to check your stats. This kid is a squid no doubt about it, but he's got very good points about back pressure (as do many of you)....no matter how much you all hate straight pipes, u can draw lots of power out of less backpressure if you tune it.

do you know what kind of pipe is on a flat track race bike? take a harley 750tt flat track bike for example. It's a single cylinder motor, air cooled. Every one of those bikes, (90% of them are harleys) on the track is running a straight pipe!

They wouldn't run a straight pipe if they weren't looking for more power people.

Well you’re wrong. Welcome to the modern age of Bernoulli’s Principle the "tuneable" Venturi tube illustrated below, also known as “cone flow”. When engineered properly no straight pipe can deliver it’s CFM. Today’s sound chamber design’s have zero loss.

http://i280.photobucket.com/albums/kk191/Terrylport/SOUND.jpg

Straight loud pipes are inefficient, if you disagree with me state some technical engineered facts and we’ll take a look at them. Dispute mine with data and I will respond with data. If I have not provided enough data let me know and I will provide more, no problem.

[f4iracer]

Originally posted by TNT
Well you’re wrong. Welcome to the modern age of Bernoulli’s Principle the "tuneable" Venturi tube illustrated below, also known as “cone flow”. When engineered properly no straight pipe can deliver it’s CFM. Today’s sound chamber design’s have zero loss.

http://i280.photobucket.com/albums/kk191/Terrylport/SOUND.jpg

Straight loud pipes are inefficient, if you disagree with me state some technical engineered facts and we’ll take a look at them. Dispute mine with data and I will respond with data. If I have not provided enough data let me know and I will provide more, no problem.

a straight pipe to me is one without packing or baffles. the taper or cone thay you see towards the end of some of the flat track bikes or go karts is for less back pressure. if the pipe didnt taper and get bigger there would be more back pressure!

i dont really need information haha thanks though.

also i cant tell u how many harleys i know with straight pipes running the same diameter all the way out the back.
especially the older pan heads.
face it guys, if ya want more power u need to let it rip

[TNT]

Originally posted by f4iracer
a straight pipe to me is one without packing or baffles. the taper or cone thay you see towards the end of some of the flat track bikes or go karts is for less back pressure. if the pipe didnt taper and get bigger there would be more back pressure!

i dont really need information haha thanks though.

also i cant tell u how many harleys i know with straight pipes running the same diameter all the way out the back.
especially the older pan heads.
face it guys, if ya want more power u need to let it rip

Well one things for sure you don't understand fluid dynamics. I was hoping for some tech data not biker primitive knowledge and speculation. :rolleyes: Well I'm done with ya have fun.

EVERYONE ELSE THAT VALUES OUR SPORT STOP LISTENING TO THIS BS BUY QUITE PIPES YOU WILL SEE MORE HP AND TORQUE AND HELP KEEP OUR TRACKS AND RIDING AREAS OPEN.

TNT
Engineer

[storms400ex]

Originally posted by TNT
Well one things for sure you don't understand fluid dynamics. I was hoping for some tech data not biker primitive knowledge and speculation. :rolleyes: Well I'm done with ya have fun.

EVERYONE ELSE THAT VALUES OUR SPORT STOP LISTENING TO THIS BS BUY QUITE PIPES YOU WILL SEE MORE HP AND TORQUE AND HELP KEEP OUR TRACKS AND RIDING AREAS OPEN.

TNT
Engineer

X-2

[f4iracer]

Originally posted by TNT
Well one things for sure you don't understand fluid dynamics. I was hoping for some tech data not biker primitive knowledge and speculation. :rolleyes: Well I'm done with ya have fun.

EVERYONE ELSE THAT VALUES OUR SPORT STOP LISTENING TO THIS BS BUY QUITE PIPES YOU WILL SEE MORE HP AND TORQUE AND HELP KEEP OUR TRACKS AND RIDING AREAS OPEN.

TNT
Engineer

Wow, quiet pipes will give you more hp and torque. HAHAHAHAHA. That's why every race quad is much quieter than every stock quad. More power right dude?

Tech data? It's right in front of your face. Show me a quiet race pipe that puts up numbers. PLEASE!. Now show me a loud race bike that puts up numbers, PLEASE!

What do you have, more numbers on a louder pipe, haha what a wierd deal???


As far as the sport goes and the noise issue, i don't see a need for straight pipes in atv parks or other public riding areas. However, if it's motocross, or flat track atv, or kart racing, or any type of fast machine racing haha. or if you have your own land with no neighbors, ride it however you want, if you are looking for power, you're gonna get noise!

[atv fan 28]

Originally posted by f4iracer
Wow, quiet pipes will give you more hp and torque. HAHAHAHAHA. That's why every race quad is much quieter than every stock quad. More power right dude?

Tech data? It's right in front of your face. Show me a quiet race pipe that puts up numbers. PLEASE!. Now show me a loud race bike that puts up numbers, PLEASE!

What do you have, more numbers on a louder pipe, haha what a wierd deal???


As far as the sport goes and the noise issue, i don't see a need for straight pipes in atv parks or other public riding areas. However, if it's motocross, or flat track atv, or kart racing, or any type of fast machine racing haha. or if you have your own land with no neighbors, ride it however you want, if you are looking for power, you're gonna get noise! as Forest Gump once said " stupid is as stupid does". when will these youngsters learn that loud pipes dont make you cool! and this is coming from someone"f4iracer" who said slip-ons dont require you to rejet!

[TNT]

ATV fan can you covert what he said to quad talk, I got no clue! :D

Last I checked the MX national pro's and pro-am’s are running 96 db with more hp and torque #'s than any 450 quads in the atv industry.

Acoustic tiles made of ceramic or composite material with the right chamber design can scramble acoustic sound signals to zero with no loss in power. Problem with the wall of the straight pipe has always been turbulence, which creates a low pressure or vacuum area and restricts flow. It's mitigated by stepping pipes with divergent and convergent ducting such as the mega bomb. Sound chambers also act as vortex generators to reduce wall turbulence and low pressure turbulent flow. The sound chamber when designed properly adds to exhaust velocity by a reduction in differential wall pressure.

F4iracer- The small divergent tapering of straight bike pipes has such a small effect on pressure and velocity its negligible with respect to back pressure.

With more and more racing tracks and riding area across the nation and in Europe closing due to noise issues, there is a growing concern which is driving quite pipe designs that are efficient. The technology in the ATV racing industry is still far behind, the Chopper boys could care less……strange how they can drive up with 130+ db pipes to our races and we got to pass 94- 96 DB tech inspect. Go figure!

What’s important to understand here is why the pipe db has to be reduced, if you put 20 quads on a track, track noise adds to the overall db levels…..that is what is driving the tech inspect dbs lower and lower. In Europe a committee was formed to study the issue, they have to be a 94 and that’s everyone I believe. It won’t be long before we in the US are the same boat since the majority of our races at the nation level are in densely populated metro areas. That’s why pro-am in 2009 had to pass the same db pro’s levels and its coming to the a-class next, etc.

So as the db requirement becomes less and less you will see more and more of the high technology in the atv pipe industry. It won’t be long before the low db high efficient pipe comes from the OEM’s race packages and aftermarket race motors. ASAE will drive the requirement to the ATV OEM, since the aftermarket industry can not handle the R& D cost nor the variance in race motors, which will develop the technology to the stock race motors they release to the public. I think you will see synergy w/Europe, Can, and the Japs on this since thier market is huge in the US, and Switzerland soon. Switz I believe were the first to form a global alliance noise reduction program that impacted Europe and the US. They were the first to run test on track noise.

There I hope I have helped a few of you youngster pro-advocates of the straight noisy pipe understand where we are at and heading in the ATV racing industry. The straight obsolete noisy pipe has no future in our industry period!

TNT RACING and TECH SUPPORT :D
Can-am #101

[JR3]

Originally posted by atv fan 28
as Forest Gump once said " stupid is as stupid does". when will these youngsters learn that loud pipes dont make you cool! and this is coming from someone"f4iracer" who said slip-ons dont require you to rejet!

yea ive seen some of this kids posts hes a joke and hes never wrong hes obviously an expert. You cant talk sense into him so stop trying. as a wise man once said "before you react to someones comment look at the person that is saying it".

[storms400ex]

:cuss: this tread is stupid

[f4iracer]

well thanks guys.

i'm not supid, just voicing my opinion on the matter.

waaaaawawawawaaaaaa.

also, slip-ons don't require a re-jet for whoever decided to bring that up.

i re-jetted mine because i did air filter and slip on with no arrestor.

My buddy has been running a white bros slipon with no rejet since he bought his 400 ex new.

[JR3]

like i said the kids obviously an expert haha

[rooster300ex]

Originally posted by f4iracer



also, slip-ons don't require a re-jet for whoever decided to bring that up.




No they don't require a re-jet, but if u want any performance gain u need to rejet

[storms400ex]

X-2 on that

[f4iracer]

X-3 on that.


that's why i said, they don't require a re-jet.

People who say they do are wrong! If you want to achieve your max power you would most likely have to re-jet it depends on the slip on.

However, you can very easily keep the stock jets and run MOST slipons, on your 400ex with no trouble at all.

You will also pick up a hair more power even with stock jets. If ya tune it with jets you will get the max power, yes. But that's not to say you won't get a little bit more power without changing jets.

[450rJam]

if a slip on alows the exhaust to flow more air then you NEED to re-jet

most atv's (not just the 400ex) come pretty lean from the factory to limit exhaust polution

if you improve the air flow but not the fuel you could cause over heating and possibly burn a hole in the piston

with winter coming on, the cold temps will make it even worse

[JR3]

Originally posted by 450rJam
if a slip on alows the exhaust to flow more air then you NEED to re-jet

most atv's (not just the 400ex) come pretty lean from the factory to limit exhaust polution

if you improve the air flow but not the fuel you could cause over heating and possibly burn a hole in the piston

with winter coming on, the cold temps will make it even worse

ur wrong man that kids a expert. if i could reach threw my computer screen and joke him i probably would

[f4iracer]

Originally posted by 450rJam
if a slip on alows the exhaust to flow more air then you NEED to re-jet

most atv's (not just the 400ex) come pretty lean from the factory to limit exhaust polution

if you improve the air flow but not the fuel you could cause over heating and possibly burn a hole in the piston

with winter coming on, the cold temps will make it even worse

JR 3, you go ahead and joke me bro. haha.

you don't need to but it will help with perfomance.

What you said about over heating and blowing up will never happen on a 400ex if all you have done to it is a slip-on.

you can run that thing all year round with a slip-on and stock jets and you won't have to worry bout blowing it, it might run a little lean but it ain't gonna blow.

Why would they sell the bike right out of the shop lean? so if you never jetted the quad it would over heat and blow eh???? NO! emissions are why it's a little on the lean side, but it's not so lean that it's gonna pop, they wouldn't set up a quad so lean that it was ready to pop, obviously honda feels that it's not too lean to be an issue. They're all about long lasting engines, i garuntee u can run a stock 400ex forever without re-jetting, same goes for a slip-on it's not enough air flow to make it run that much more lean. it's fine to run a slip-on without re-jetting, if you're looking for max gains, u might as well rejet.

[tayyo789]

Back to the topic,

straight pipes=not worth it, in any way

proper jetting=important, but isnt relevant to the debate about straight pipes

[tayyo789]

Originally posted by f4iracer
X-3 on that.


that's why i said, they don't require a re-jet.

People who say they do are wrong! If you want to achieve your max power you would most likely have to re-jet it depends on the slip on.

However, you can very easily keep the stock jets and run MOST slipons, on your 400ex with no trouble at all.


You dont HAVE to put oil in your bike either, but that doesnt mean its optional

[f4iracer]

a quad can run lean with a slip-on for 10 years, won't hurt anything.

a quad cannot run without oil for 10 years.

it was a good comparison though..........

[BakerRacing40]

haven't read back far on this.. i can't believe this thread is still going.

lean is mean but you'll burn it up if your too lean. quads run lean from the factory to meet the standards that are required, lean with mods that make it more lean equals too lean and time to rebuild if it goes to long.. if you run too rich you wash out your rings and cylinder ...

[tayyo789]

Originally posted by f4iracer
a quad can run lean with a slip-on for 10 years, won't hurt anything.

a quad cannot run without oil for 10 years.

it was a good comparison though..........

I was being extremely sarcastic. the problem with running lean is that when your bike is running a little bit lean it actually produces more power, and why would you change the jets if it runs worse when you do? eventually, something will break. it all depends on HOW lean it is. another common problem is when someone just gets a slip on. if there is somebody on here that gets JUST a slip on, i want to congratulate them. they deserve an applause

[ian0615]

why would someone want to run a straight pipe on an atv?? I even worry that my pipe is to loud at times and to tell ya the truth its kida embarassing! after all i do like riding at the places i ride at and the last thing i want to do is annoy the people around me.
I even get poopy looks on my harley, but there isnt much i can do about that !! dosent make much sense mechanicaly or "just for sound" get a good used pipe off ebay with 90+db and it will still sound good and function well