more power???? [Archive] - ATV Riders Forum

400exshop

11-03-2010, 05:19 PM

The bigest thing you can do to make it have more power is head work. Go to Racers Edgeaz.com from what i hear there numder one in head work. Get the head ported and polish and all so have them flow test it. Then get a 450er carb not the 450r carb it's a vac.carb. a stage 1 h/c will be best for a stock bore.

3400ben

11-03-2010, 05:22 PM

What mods are allowed for the class? What mods are not allowed in the class? That would help! Is it xc, Tt , or mx?

400exshop

11-03-2010, 05:22 PM

If you get a 450 er carb i would jet it on a dyno so you can get the most out of what you'r doing.

ish416

11-03-2010, 05:29 PM

Are all the mods in your sig on this quad? If so, looks like you have things covered.

Basically, if you have to run a stock bore and make the most amount of power. Here is what I would do.

85mm (stock bore)12:1 piston, hotcam stage 2, full exhaust, 04-05 450R carb or Sudco FCR, port and polish, OEM XR400R head gasket (to keep your compression ratio), jetted for race fuel or E85 if you have access to it, GT Thunder head studs and a good clutch basket.

Then just change the gearing depending on the track you are running.

I believe that will give you the most powerful stock bore EX that you can have.

Don't run a timing key as it will cause issues running that compression ratio.

Also, if you tear apart the top end, USE THE FACTORY XR400R HEAD GASKET!!
They are thinner than the 400ex gaskets and the compression ratio of your piston is most likely achieved using this gasket. You usually loose about .25 of compression from the 400ex head gaskets. Also, some people do not use a base gasket on the 400's, that can give you a slight bit of compression as well.

rubbersdown

11-03-2010, 05:47 PM

Originally posted by 400exshop
The bigest thing you can do to make it have more power is head work. Go to Racers Edgeaz.com from what i hear there numder one in head work. Get the head ported and polish and all so have them flow test it. Then get a 450er carb not the 450r carb it's a vac.carb. a stage 1 h/c will be best for a stock bore.

Racers edge is the ish, they build some of the baddest quads, bikes and utv's you have ever seen. I live about 15 min from their shop and have been there a million times. Nicest guys in the world and do top notch work on everything from port and polish to custom turbo and nos atv builds.

87HONDATRX250X

11-03-2010, 05:51 PM

Mods are allowed as long as i stay under 400cc. I race mx. All my mods are in my sig that are on the quad this moment. How much do you think it would run me to get all that done "ish416" ?? Also looking at some stag 3 Elka shocks and long travel and JB Racing a-arms +3+1

bherriman

11-03-2010, 07:11 PM

Originally posted by 400exshop
The bigest thing you can do to make it have more power is head work. Go to Racers Edgeaz.com from what i hear there numder one in head work. Get the head ported and polish and all so have them flow test it. Then get a 450er carb not the 450r carb it's a vac.carb. a stage 1 h/c will be best for a stock bore.

This is just my opinion, but if you are wanting to do a big p/p like Eric is talking about, a stage 1 hotcam wouldn't be the way to go. Porting and polishing moves the power up in the rpm range and opens up so HP. The stage 1 hotcam grind produces lots of low end tourqe. I would go stage 2, but thats just my own opinion.

87HONDATRX250X

11-03-2010, 07:40 PM

ish416

11-03-2010, 07:49 PM

Looking through your sig, this is all I think you will need.

Piston 12:1 standard bore - $160 may cost a little more since you are in Canada Ebay Link (http://cgi.ebay.com/ebaymotors/HONDA-400EX-TRX400EX-JE-PISTON-KIT-STD-BORE-12-1-_W0QQcmdZViewItemQQhashZitem35ad8b0190QQitemZ23054 4834960QQptZMotorsQ5fATVQ5fPartsQ5fAccessories#ht_ 2351wt_1166)

OEM XR400r head gasket $20

Various other 400ex gaskets to put top end back together $35

Cylinder Hone - depends on shop where you take it - $30 -$80

04-05 450R Carb + jets = $150

GT Thunder HD Head Studs - $60
Link to GT Thunder 400EX page. (http://www.gtthunder.com/TRX400EX.htm)

Headwork, port and polish - $100 - $300 depending on who does it. You won't need to go all out on the p&p unless you are running a larger piston. Just a basic port job should be fine.

I think that's about it for your build.

Grand total should be around $600 - $700 all depending on how much of the work you can do and how the shops treat you on pricing.

An EX with +2+1's handles amazing. So a +3+1 should even be a bit better especially with elka shocks. I haven't ridden the stage 3 elka's but the stage 4's are amazing.

With all the mods together, you will have an amazing stock bore EX.

EDIT**

I noticed that you have a Ross piston listed in your sig, if it is 11:1 I would just leave that alone. If you run a 12:1 piston you will have to run race fuel or E85.

87HONDATRX250X

11-03-2010, 07:54 PM

thanks for the info. Ill see how much i can afford and get done over the winter.

pmg8134

11-03-2010, 07:57 PM

stage 3`s are the sh*&^%%$%$%%$$T!

ish416

11-03-2010, 08:05 PM

stage 3`s are the sh*&^%%$%$%%$$T!

Stage 3's do not work that well on a stock bore EX.

He already has a stage 2, no real need to upgrade.

87HONDATRX250X

11-03-2010, 08:07 PM

stage 1 is fore trail riding and stage 2 is for mx and i believe stag 3 is for drag racing and dunes or something a rather.

pmg8134

11-03-2010, 08:19 PM

i hear ya sorry off topic just like my setup

CJM

11-03-2010, 08:42 PM

I personally feel a small boreing would be best, 406, 416 with a 11:1 piston and stage 1 or 2 hotcam. Im happy with mine and it is easily as fast as a 450r or better.

honda400ex2003

11-03-2010, 08:47 PM

x2 great setups here though. I like mine thats for sure. steve

Nac's22

11-03-2010, 09:30 PM

Originally posted by CJM
I personally feel a small boreing would be best, 406, 416 with a 11:1 piston and stage 1 or 2 hotcam. Im happy with mine and it is easily as fast as a 450r or better.

The rule in the class states that he has to stay under 400cc. If he was allowed to bore it though I'd be in full agreement with the 416, I love mine more then when it was a 440.

I'm not sure of the other rules of the class but in the US, most of the width rule is 50" so if you get the +3+1 front end, get +1 -4 front wheels to stay within this.

CJM

11-03-2010, 09:32 PM

Ohh didnt notice that part.

Then def 11:1 or 12:1 with the gasket work, cam, exhaust, sparks key and outwears or ditch the airbox lid. SHould be good. Also check your gearing too.

trailrider894

11-03-2010, 10:15 PM

DO NOT GET ELKA SHOCKS. I am telling you that you will regret it. You will spending to much money on a shock that isn't worth the money. If you have YFZ or 450r shocks you can do stock conversions with I-Shock which does amazing work!! and i think they run around $650 for all three shocks. Avoid Works shocks, and Elka. PEP, Ohlin, I-Shock, AXIS make the best shocks. If you are gonna spend that much money on shocks you need to do more re-search, because i gurantee you can get more bang for your buck than what you will get with elka's.

trailrider894

11-03-2010, 10:17 PM

You may want to budget for CNC Puck-style steering stabilizer also.

400exshop

11-04-2010, 05:14 AM

Originally posted by bherriman
This is just my opinion, but if you are wanting to do a big p/p like Eric is talking about, a stage 1 hotcam wouldn't be the way to go. Porting and polishing moves the power up in the rpm range and opens up so HP. The stage 1 hotcam grind produces lots of low end tourqe. I would go stage 2, but thats just my own opinion. If you think about what you just said. You will see why i said port & polish the head and a stage 1 h/c would be good. ( 1 ) stage 1 h/c help's on the bottom end. ( 2 ) The p/p will help on the mid to top end. And with a nice p/p it will unleash all the power. But now that you already have the stage 2 keep it. Also it just me But i would run 15/36.

bherriman

11-04-2010, 10:35 AM

Originally posted by 400exshop
If you think about what you just said. You will see why i said port & polish the head and a stage 1 h/c would be good. ( 1 ) stage 1 h/c help's on the bottom end. ( 2 ) The p/p will help on the mid to top end. And with a nice p/p it will unleash all the power. But now that you already have the stage 2 keep it. Also it just me But i would run 15/36.

If you think about what you just said, you will see why you are still wrong. A big p/p and a stage 1 together will not perform optimally. It like trying to take a college running back who is fast and lean ( think of it like the p/p moving lots of air) and combining him with a huge Defensive lineman (stage one hotcam) and then trying to turn him into a wide-out. It will work, just not as well as it could. I know that was a terrible analogy but its all i can think of at the moment lol. You can just combine to totally opposite things and hope they meet in the middle, which is what you are suggesting by doing a big port and polish, which, moves the power up in the rpm range, and trying to throw in a stage one which moves the power down in the rpm.

trailrider894

11-04-2010, 10:51 AM

okay... listen. A cam changes the lift of the valves. You must get the proper P/P to match the lift of the cam you got. Talk to the person who is doing your P/P and HE WILL KNOW WHAT TO DO. I think that a MILD P/P will suffice for a stock setup. When you increase the lift of the cam, that means more air is going to be flowing through and you must P/P to match that amount. I send in the cam and or specs for the cam when i get the P/P done so that i know i am getting the correct specs for my P/P. I think that talking to C&D will get you eons further than talking to people on here. None of us are machining specialists or people who have been doing P/P's for years. Talk to C&D or GT Thunder about it and they will tell you what you need.

Go here for your P/P (http://www.hungracingengines.com/)

I recommend these guys for your P/P he does amazing work!! He has been doing P/P work for years and will know exactly what to do for you.

bherriman

11-04-2010, 03:07 PM

Originally posted by trailrider894
okay... listen. A cam changes the lift of the valves. You must get the proper P/P to match the lift of the cam you got. Talk to the person who is doing your P/P and HE WILL KNOW WHAT TO DO. I think that a MILD P/P will suffice for a stock setup. When you increase the lift of the cam, that means more air is going to be flowing through and you must P/P to match that amount. I send in the cam and or specs for the cam when i get the P/P done so that i know i am getting the correct specs for my P/P. I think that talking to C&D will get you eons further than talking to people on here. None of us are machining specialists or people who have been doing P/P's for years. Talk to C&D or GT Thunder about it and they will tell you what you need.

Go here for your P/P (http://www.hungracingengines.com/)

I recommend these guys for your P/P he does amazing work!! He has been doing P/P work for years and will know exactly what to do for you.

Actually the lift and duration of the cam change when and how long the valve stays open. The rest of what you said is fairly accurate. However there are people on here that know what they are doing. I happen to think I am one of them. I think I am sending the wrong message here though. An aggressive p/p and a stage 1 hotcam will work together and probably very well with a stock bore high compression motor, however, He wants to most power possible while staying under 400 cc so in this case a stage one is not the ideal route to go. If I were building this for my personal use I would chose one of the three: Stage 2 hotcam- Stock xr 400 cam - sparks X-1.

87HONDATRX250X

11-04-2010, 03:43 PM

whats wrong with elka? Every one i know who has or had some loved them.. Im not buying them new so im not putting out more then a grand for the whole set up. I priced it out my self and i wouldn't even be paying 1/3 of the cost bran new.

beags86

11-04-2010, 05:25 PM

my advice for ya is practice, practice, practice. less time on the forum, more time riding.

and if you feel the need to spend money, you have 450 shocks, have them re-vavled and resprung.

also: a good set of arms

engine i would say with your mods you have a solid start, i would hone it, re-ring it and spend some bucks on a good p&p and vavle job.i have found out that just freshing things up does wonders

f4iracer

11-04-2010, 05:50 PM

Originally posted by CJM
I personally feel a small boreing would be best, 406, 416 with a 11:1 piston and stage 1 or 2 hotcam. Im happy with mine and it is easily as fast as a 450r or better.

you are out of your mind bro.

450r will smoke your little 416 dude get real.

also, why does bherriman always have to argue and know it all.

that being said i've got a 416 i'm waiting to install. figured i'd try to run the heck out of this stocksetup for the time being.

i dont intend to hang with the 450's that's just not gonna happen.

3400ben

11-04-2010, 06:49 PM

This is getting better every post! I think this last post started it down hill!

iSavage504

11-04-2010, 07:10 PM

....test....

87HONDATRX250X

11-04-2010, 08:25 PM

i dont wanna send to much more on it because who knows when ill get a 450. I like my shocks but i need wider aarms and not offset rims. The guy still hasn't emailed me back so not sure what my next option would be. Sounds like the p/d is a good idea. Any catches with the sparks timing key?

bherriman

11-04-2010, 08:58 PM

Originally posted by f4iracer
you are out of your mind bro.

450r will smoke your little 416 dude get real.

also, why does bherriman always have to argue and know it all.

that being said i've got a 416 i'm waiting to install. figured i'd try to run the heck out of this stocksetup for the time being.

i dont intend to hang with the 450's that's just not gonna happen.

This is coming from a guy that thinks 400 ex's have lifters and pushrods.....the whole 400ex section has turned into a total joke.I argue because people are wrong/mis informed and need to be corrected, and I'm always right.

Getting your 450 shocks re-sprung and valved is a very good idea, its rather cheap and they will perform great.

honda400ex2003

11-04-2010, 10:00 PM

as you can see i have not been on too much the past week. there is a reason... it is revenge of the idiots that think they know about machines and what works. oh well, ill keep to myself and away from this thread unfortunately. i would cause some major trouble indeed. lol steve

CJM

11-04-2010, 10:14 PM

Originally posted by honda400ex2003
as you can see i have not been on too much the past week. there is a reason... it is revenge of the idiots that think they know about machines and what works. oh well, ill keep to myself and away from this thread unfortunately. i would cause some major trouble indeed. lol steve

Yep. I think Ill shut up except for this:

A properly done 416 or 426 makes the power you need to keep up if not beat the 450r's. Your not gonna be faster than someone with a worked 450r but keeping up aint no issue for those of us who built it right.

2 weeks ago I dragged 2 different 450rs, just stock units nothing special. I didnt do it by a landslide but they just couldnt get ahead of me. Then we swapped to make sure and same result.

So yea a properly done machine can do it. It wont be a 450r but you spend WAY less in initial cost and upkeep imho.

Think of it like this, Im a mechanic and I can build a 350 that would rival even a 427 big block if I did it right.

Oh last thing: if you have a stock quad you cant even begin to try and tell us how a 416 is slow vs a 450r. really, cmon man give us all a break.

ish416

11-05-2010, 02:38 AM

I understand not wanting to spend a bunch of money on something you may not be keeping for much longer.

Do you have any idea on how much money you are wanting to spend on the engine so we can try to recommend the things that will have the most bang for the buck.

With your mods, you should get the head ported and run an 04-05 450R carb, those together should get you a nice bump in power.

What compression ratio is your engine running? Just asking because you have a Ross piston listed in your sig.

The catch with running a timing key has to do with a high compression piston. If you have a high compression piston and run a timing key, you run a very good change of destroying your engine. Typically, the higher your compression ratio the less advanced timing you can run. To much timing can cause detonation and cause engine failure. Best bet is 11:1 no more than +3 timing and even then you are walking the line on pump fuel. It should be safe with E85 or race fuel. 12:1 you should just run stock timing and E85 or race fuel.

As far as suspension, I would suggest getting your YFZ450 shocks re-valved if you plan on staying with the stock length a-arms. Otherwise, look for an actual long travel setup.

400exshop

11-05-2010, 06:21 AM

look man head work on a 4stroke is key to HP.......... and just becouse i drag mine does not mean i cant put it back on a mx track and hand your back side to you lol i still ride mx. my drag motor does nice on mx and trails. we had it set up 2 weeks ago and it did great p/s i will not spray it in a corner again.

tri5ron

11-05-2010, 07:53 AM

Why are we here ???

Do fish get thirsty ???

Is the moon really made of cheese ???

Why is it called a Homerun, when you are at the park ???

How come submarines dont have windows ???

and a couple from George Carlin..

"Think of how stupid the average person is, and realize half of them are stupider than that."

"The very existence of flame-throwers proves that some time, somewhere, someone said to themselves, You know, I want to set those people over there on fire, but I'm just not close enough to get the job done."

3400ben

11-05-2010, 08:49 AM

Why does one that lives in a house made of glass change there clothes in the basement??????

400exshop

11-05-2010, 10:19 AM

Why does some people clame to know some much and realy dont know much of any thing ? and back to what post at hand good luck with you'r 400ex

honda400ex2003

11-05-2010, 10:30 AM

Originally posted by 400exshop
Why does some people clame to know some much and realy dont know much of any thing ? and back to what post at hand good luck with you'r 400ex

some people even think they know alot about a 400ex engine and then ask if a 426 can be done on a stock sleeve without problem. Some of them cant even spell right, thus making their whole existance and knowledge base non-existant. :blah:

All joking aside, some of this info is hilarious lol man am i glad it is friday. in a matter of hours i will be ripping up the woods on some sort of off road vehicle, not sure which one yet though. oh the decisions some have to make... it is a tough, cruel world out there peeps. 2 stroke or 4, 4x4 or 2x4, red or yellow. man the choices are almost endless. steve

tri5ron

11-05-2010, 12:45 PM

You Go Steve !
Wish I could join you.

Ride Hard, Ride safe, and Keep the rubber side Down !

VVVV ( I'll translate it for those who are having trouble with it ) VVVV

Uuew goe Stiiv !
Wheich eiy cuuld geoin uew.

Reyd Hurde, Reide Saaife, un Kiepe duh ruebrr sayed Dunn !

:eek2: :devil: :eek2: :devil:

87HONDATRX250X

11-05-2010, 01:42 PM

Not sure the compression. I got the quad with it in. I dont want to keep my stock aarms now that i have itp rims that are not offset i find it to tipsy in corners for my liking. Any one happen to have some long travels and shocks going for cheap? Still no reply back from the guy. Still not sure what ill do for motor work. Seems this forum turned into whats the best bore and compression vs not allowed to bore over 400cc. :rolleyes:

bherriman

11-05-2010, 03:20 PM

Originally posted by 400exshop
Why does some people clame to know some much and realy dont know much of any thing ? and back to what post at hand good luck with you'r 400ex

Dude if you are still talking about me, its pointless..I can guarantee I know more than you. You're an idiot and thats all there is to it. The sad thing is that I too am an idiot for responding to you, therefore, I'm done with this thread and probably the forum, its a total disaster theese days.

Thank you! Come again !