custom exhaust

[400exrider26400]

has anyone ever made a custom exhaust from the stock 400ex exhaust or from scratch??
if yes post some pics

[bigd's ex]

Originally posted by 400exrider26400
has anyone ever made a custom exhaust from the stock 400ex exhaust or from scratch??
if yes post some pics

Read this thread. He did a helluva good job on these.http://www.exriders.com/vbb/showthread.php?s=&threadid=379722&highlight=exhaust

[Pipeless416]

thanks :) . on a side note, we got pulled over for sound tests on sunday.. passed with flying colors :cool:

[bergoff]

where did you get pulled over at.

[Pipeless416]

cheese country trail of course. 100 yards from our truck in darlington haha. the police officer was just doing random checks (all the sport quads.)

[bergoff]

that damn trail. but they have to do their job. beags86 was busted on it awhile ago. there is now way that i will pass a sound check. white bros r4 is loud as heck.

[Pipeless416]

yea, if i still had the single exhaust i would have been screwed. the guy was pretty cool after we all passed. him-"got a couple mods, huh?" me-"yea, a few" :devil:

[Snipe]

I know Dirt Works in willow springs missouri makes custom exhaust's but have never had them do one I dont trust them to awful much. Mostly out for money more than anything.

As for cutome I dont know of anyone making a true custome exhaust I tried once but couldnt find anyone to bend me some header pipes.

[killer400ex]

i dont think you will ever get a "good" custom exhaust just due to performance, you might find someone to make a nice looking or sounding exhaust but performance gains take countless hours of testing to make it good, why do you think all other exhausts are so expensive, not because of the materials but because of the labor and hours put into it, also because most company's are out to make money, but if you want to try to make one and you dont care how it performs then i would do it, like if you had a spare pipe or whatever, and i wouldnt screw with the head pipes either, i wouldn't want to burn my valves or anything like that

[Pipeless416]

Originally posted by killer400ex
i dont think you will ever get a "good" custom exhaust just due to performance, you might find someone to make a nice looking or sounding exhaust but performance gains take countless hours of testing to make it good, why do you think all other exhausts are so expensive, not because of the materials but because of the labor and hours put into it, also because most company's are out to make money, but if you want to try to make one and you dont care how it performs then i would do it, like if you had a spare pipe or whatever, and i wouldnt screw with the head pipes either, i wouldn't want to burn my valves or anything like that

there honestly isn't a whole lot that you could do to "burn up" the valves. JETTING JETTING JETTING

[killer400ex]

yeah jetting i get it but it will never run like a professionally tuned exhaust, im sure you can make a nice one but you wont get the gains over the whole rpm range, you will usally end up one sided or making power at a certain rpm, like a bigger exhaust will give you better top end while a smaller one would help with bottom end, im not discouraging it i am just giving him a heads up before he rips apart his exhaust, and it can burn your valves because your pipe acts like a vacuum, the length and width of the headers and pipe are all factors, you want the last exhaust wave to create a vacuum in the pipe so that it pulls the next one out, alot of people think that 4 strokes need back pressure, that isnt the case, sure a slight ammount will help but not if you create too much pressure, again this is where the countless hours of testing defferent designs and sizes come into play, if you just want to screw with the silencer or make your own slip on then go for it it wont hurt it that much if at all but i was talking about altering the midpipe and headers

Originally posted by killer400ex
yeah jetting i get it but it will never run like a professionally tuned exhaust, im sure you can make a nice one but you wont get the gains over the whole rpm range, you will usally end up one sided or making power at a certain rpm, like a bigger exhaust will give you better top end while a smaller one would help with bottom end, im not discouraging it i am just giving him a heads up before he rips apart his exhaust, and it can burn your valves because your pipe acts like a vacuum, the length and width of the headers and pipe are all factors, you want the last exhaust wave to create a vacuum in the pipe so that it pulls the next one out, alot of people think that 4 strokes need back pressure, that isnt the case, sure a slight ammount will help but not if you create too much pressure, again this is where the countless hours of testing defferent designs and sizes come into play, if you just want to screw with the silencer or make your own slip on then go for it it wont hurt it that much if at all but i was talking about altering the midpipe and headers

That whole burning exhaust valves thing is a load of crap. My buddy had this piece of crap, beat up LT230. He never had a muffler OR header on it, just right out the cylinder. EVERY day he would race around the roads WOT. Never ONCE affected the valves. So I doubt a custom header would.

that's my $.02

[killer400ex]

when you burn your valves you are just setting yourself up for failure, it can weaken them or warp them, just because it sounds good dosnt mean jack in my opinion, and also yeah his valves might acually stay cooler because they are dissipating the heat instantly into the air, i am talking about acually having an exhaust, i could run pipeless too and be fine but i perferr to have a good performing machine as well as having it be reliable, and once you get rust building up in your exhaust or they start to oxidize you are screwed, and it will happen because the heat attracts moisture as it cools which is why your header will change colors and eventually build rust on it unless you have a protective coating, you can run it but it dosnt mean its good for it, i can pour water in my oil and run my quad but it dosnt mean its good for it if you get what i mean

[Snipe]

I agree with killer on this. To much back pressure or not enough exhaust flow can cause the heat temp of the exhaust to change and create swirling in the pipe creating lower exhaust output. To much heat can cause valve problems. Usually the biggest issue is burning of valve seats then that cause's the valve issue that causes the valve to go bad.

As long as the exhaust wasnt choked down or a crappy bend I dont think it would be any problem in causing over heating of the valves. Hell to big of a pipe can cause the same thing. The outside air cools faster while the inside exhaust air is hot and causes swirling instead of a smooth exhaust putout.

As far as the silencer goes most all aftermarket exhaust's have a peak at one spot not over the whole range and most all peak at a mid to high mid RPM, I have yet to see a dyno of any that peak at low or high RPM ranges.

You wouldnt loose much but yet you wouldnt gain much other than having an exhaust no one els has.

[Pipeless416]

Originally posted by Snipe
I agree with killer on this. To much back pressure or not enough exhaust flow can cause the heat temp of the exhaust to change and create swirling in the pipe creating lower exhaust output. To much heat can cause valve problems. Usually the biggest issue is burning of valve seats then that cause's the valve issue that causes the valve to go bad.

As long as the exhaust wasnt choked down or a crappy bend I dont think it would be any problem in causing over heating of the valves. Hell to big of a pipe can cause the same thing. The outside air cools faster while the inside exhaust air is hot and causes swirling instead of a smooth exhaust putout.

As far as the silencer goes most all aftermarket exhaust's have a peak at one spot not over the whole range and most all peak at a mid to high mid RPM, I have yet to see a dyno of any that peak at low or high RPM ranges.

You wouldnt loose much but yet you wouldnt gain much other than having an exhaust no one els has.

i still don't completely agree with the burning valve thing, because no matter what, the exhaust won't be that radical to mess up anything. i do agree with your last point though. i didn't lose any performance, in fact i might have gained a little top end. the thing i really did lose was about 5 dB's, which was the goal.

[killer400ex]

like i said you can screw with the silencer all you want, just leave the heads to the pro's who spend more time testing than we do riding

[sab24711]

one other thing that needs to be certain when creating an exhaust is equal lengths. you don't want one pipe longer than the other, or have a different bend in one pipe and a whole other design for the next.

[400exrider26400]

Originally posted by DMC-4OOEX
That whole burning exhaust valves thing is a load of crap. My buddy had this piece of crap, beat up LT230. He never had a muffler OR header on it, just right out the cylinder. EVERY day he would race around the roads WOT. Never ONCE affected the valves. So I doubt a custom header would.

that's my $.02


ahahah lmao
totaly agree
my cousin 3 wheeler as been straight pipe for years and its been true lots of **** and still runs strong

[Snipe]

Straight pipes are different, running an exhaust straight out the head wouldnt burn anything as there would be no pressure at all.

And in most cases your not actually burning the valve your burning the seat for the valve and that can cause valve damage. It can happen research it it can go more into depth on it.