WHICH 400ex Exhaust is biggest POWER gains

[07trx400ex]

I just bought a 07 400ex new and am really enjoying the machine i mostly ride trails and hit the track with my friends sometimes(not much though) and just for fun. My machine is bone stock.

I want to know what brand to of exhaust to use. Which has the best low to midrange power and best sound(i know sound is opinion though).

I do not care how loud it is and would even want a louder exhaust. I just want to know which exhuast is best all out power especially low to midrange torque.

I think i have decided to get full system with k&N filter but any suggestions on basic mods would be greatly appreciated

HMF has some pretty impresive torque gains as well as HP. You cant really beat a Curtis Sparks on a 400ex but look at the price tag for an extra bit of power and a bit nicer looking exhaust

[07trx400ex]

alright thanks i have mostly been looking at hmf and yoshi and i think the hmf is more power without as much cost

thanks for the input

[STEVER925]

curtis sparks is the best.

[trx400EXtreme]

^^^agreed...... if your willin' to pay a pretty penny.

[07trx400ex]

alright im lookin it up on their website now

Does anyone have any hp numbers or did any mags do any testing on this
any help would be great thanks

If you want to see some HP and torque gains here ya go.

Heres torque pretty impressive all from a slip on

[hess442]

i have a curits sparks x-6 system and the low end increased alot. i am happy wit it. just the the only thing is, is that the head pipe tarnishes alot, mine did and other peoples i know as well.

[07trx400ex]

ok thanks i need as many opinions as possible especially people with the


HMF

Curtis Sparks

T4

And Yoshi Full systems

and do u have to be rejetted with exhaust
and should i do any other mods at same time?

[07trx400ex]

ok thanks i need as many opinions as possible especially people with the


HMF

Curtis Sparks

T4

And Yoshi Full systems

and do u have to be rejetted with exhaust
and should i do any other mods at same time?

HMF has a great sound, deep, loud. Give a very noticeable increase in power. True life example (When I had stock exhaust and my brother had the HMF, K&N, air box lid removed we like to fool around doing wheelies. On mine 1st gear to easy and quick for faster wheelies, 2nd gear gets it up there if you hit it right, try starting a wheeling from rolling in 3rd I get a stutter then a bog then a bit lift then it goes right back down. My brothers I get on it let me try yours really quick. I get on it, 2nd gear wheelies was easy as cake, 3rd gear it got right up there no problem, no bog or anything. ) The HMF deffinately has some great gans and for the money you really cant beat it.

[coryatver]

this horse has been Beat. If you do a search for it you will find a lot of info.

[07trx400ex]

alright just tell me where to look

[07trx400ex]

come on guys i need as many opinions as possible especially people that actually have full systems that would be VERY helpful

[REPOMAN]

i have curtis sparks and it is the best hands down. if money is not a problem then get the best. and the best is curtis sparks

[07trx400ex]

thanks man
how noticeable is it over stock and should i get slip or full

[REPOMAN]

gains over stock is enormous. my wife had a stock 400ex with a k&n i had a stock motor with the same filter and full exhaust and the difference was crazy. now with my 440 kit i hang with my buddies ported head, full exhaust, and filter yfz450. i would get the whole kit if its in your price range.

[Pipeless416]

just dont get the sparks if sound is an issue.

[REPOMAN]

hmm my sparks sounds great never had any complaints. only complaints i ever hear about sparks are from people who cant afford there own.

[07trx400ex]

will a honda dealer do the rejetting or should i just try it myself i am new to quads and this type of thing but am eager to learn the ins and outs

also how would the curtis sparks complete kit compare to a similar "HMF" kit solely based on performance

[07trx400ex]

oh yeah i am also looking at the yoshimura rs3 carbon fiber full system would that or sparks be better for low end

[drew416ex]

Had a sparks x-4 and have a sparks x-6, along with some other pipes and they are the best. The x-4 gave a little better low to mid but they both give great gains.

[Pipeless416]

Originally posted by 07trx400ex
will a honda dealer do the rejetting or should i just try it myself i am new to quads and this type of thing but am eager to learn the ins and outs

also how would the curtis sparks complete kit compare to a similar "HMF" kit solely based on performance

the sparks will give you a slight edge. the only reason i have an HMF instead is so i can run a quiet core. we ride wisconsin trails and if i ran my pipe wide open i would need to take a loan out for the fines.

[07trx400ex]

alright still needing more opinions especially from yoshi and hmf guys

Keep it coming thanks for the psts so far

[400ex_rider13]

Originally posted by Pipeless416
the sparks will give you a slight edge. the only reason i have an HMF instead is so i can run a quiet core. we ride wisconsin trails and if i ran my pipe wide open i would need to take a loan out for the fines.

You can get a Quiet Core for the Curtis Sparks X-6 and X-4. The X-6 is next on my list, I've been talking to CSR, they make quiet cores.
My choice for exhaust's would be:

1st: Curtis Sparks X6
2nd: Full HMF
3rd: Full Yoshi RS-C 3

[Chris102371]

Dirt wheels did a pipe shoot out a few years back and named the white bro's e2 the best pipe.:D

[CSR400EX]

thats dirtwheels for ya lol. i had both, dont get me wrong, the WB was a great system, but the Sparks is the best IMO.

[chayes627]

i also saw a comparison in 4 wheel atv action and they actually named the pro circuit t-4 slip on the best performer. the best torque gains and 3/4 of a hp above the others. also the t-4 slip on has a nice deep throaty sound to it i like it. i would stick with the stock head pipe for now cause it has good flow to start with and it will with help with throttle response. to get even better flow hornetgod13 has a great diy thread on here for your stock head pipe.

[chayes627]

also there is no need to rejet. bump up the fuel/air mixture ride it see how it is and make adjustments

[TRXRacer1]

The truth is you'll be hard pressed to find much a difference in any of the pipes you mentioned. I mean we're really talking about 3/4 hp difference between them so just get the system you'd like to see hanging off of your bike. I have the T4 slip on with the stock head pipe (with the mod) and I've NEVER had anyone beat me because of the brand of pipe they run!

Also....................... rejet is a must even for a stock machine! It's going to be close where it is so forget the dealer, buy a couple main jets, a 40 slow jet and let us help you out. Jetting is a valuable skill to learn.

Seriously, forget what everyone is saying and just get what you like, you've named some good pipes.

[shockwave95]

Originally posted by drew416ex
Had a sparks x-4 and have a sparks x-6, along with some other pipes and they are the best. The x-4 gave a little better low to mid but they both give great gains.

I have a question for you, I am looking at buying a sparks system but I am not sure what pipe to buy between de x4 and x6. Witch one did you like the most? I was looking more at the x4 with my currant mod listed below.

[mittman]

i have a full yosh and it was a major difference when i put it on. when i got it, it said you do not have to rejet but i also put a k&n on so i had to. but its your money not mine just what ever you do do not get dg!!!!!

[Chris102371]

You may want to check out rockymountains lexx pipe. It's been getting alot of good reviews from the people that have bought it and its only 200.00 compared to the others.:macho

[TRXRacer1]

Originally posted by Chris102371
You may want to check out rockymountains lexx pipe. It's been getting alot of good reviews from the people that have bought it and its only 200.00 compared to the others.:macho My buddy is getting that for his 450r soon. It looks like a winner and you can't beat the price. I know now that I wouldn't shell out big bucks like I did last time.

[maxfior]

Originally posted by TRXRacer1
The truth is you'll be hard pressed to find much a difference in any of the pipes you mentioned. I mean we're really talking about 3/4 hp difference between them so just get the system you'd like to see hanging off of your bike. I have the T4 slip on with the stock head pipe (with the mod) and I've NEVER had anyone beat me because of the brand of pipe they run!

Also....................... rejet is a must even for a stock machine! It's going to be close where it is so forget the dealer, buy a couple main jets, a 40 slow jet and let us help you out. Jetting is a valuable skill to learn.

Seriously, forget what everyone is saying and just get what you like, you've named some good pipes.

X2. I agree here, you are going to want to mess with jetting first, even a rejet with a stock exhaust will show a nice improvement, but one thing that I would like to know is how many $'s do you have to spend. Lexx might be a good option for you to start since it's a good price! Or keep a look out for good used stuff, that is where I got my HMF and I love it! Way too loud for trails though, but I also have the quiet core which helps quite a bit! Good luck!

Max

[07trx400ex]

i do not really have a budget right now but since i am just riding for fun i dont want to go over about 1000 to 1500 dollars on total mods and i also want get nerfs and skids swing+chassis and shock upgrade would be nice so i think i would rather get used topend parts than new lowend parts but just tell me what u guys think because i am new to this and need help but i love riding and am always lookin for ways to improve my machine

[07trx400ex]

in response to maxfior i can afford any part i just would like to get the best value yeah im one of those people lol

but the one thing i dont want to have to replace anything down the road if i put something on the bike i want it to last forever and not go into it thinking i will want to change down the road,

thanks for the advice keep the replies coming thanks guys

[maxfior]

Originally posted by 07trx400ex
in response to maxfior i can afford any part i just would like to get the best value yeah im one of those people lol

but the one thing i dont want to have to replace anything down the road if i put something on the bike i want it to last forever and not go into it thinking i will want to change down the road,

thanks for the advice keep the replies coming thanks guys

...Having said that... I would get nerfs, bumper, etc before getting the pipe. You'll want to keep that thing protected. Then, re-jet the carb with your stock exhaust, it'll make a HUGE difference. You can also get an air box lid pre-filter. Then, you could step up to the pipe. Just my $0.02. Because, believe me, you can spend a fortune on these f'ing things... Just ask HornetGod ;)

Max

[Hondamaster5505]

After running the DMC for a while, im a true believer in it.

Such an impressive power gain, unique sound, and good looks.

Only problem is they are hard to find.

[drew416ex]

Originally posted by shockwave95
I have a question for you, I am looking at buying a sparks system but I am not sure what pipe to buy between de x4 and x6. Witch one did you like the most? I was looking more at the x4 with my currant mod listed below.

They are both great and both give gains all around, but it depends where you want your power. The x-4 gives a little more low to mid while the x-6 gives a little better mid to top. Dont let anyone tell you that the x-4 is just for stock engines because its not, it just has better gains low to mid than the x-6. The benefit of the x-6 is you can get it in stainless. I dunno if they make the x-4 in stainless anymore.

[07trx400ex]

i am also looking at the duncan racing fat boy 2 does anyone have any experience with that and also is there a dual exhaust available for the 400 and does it add too much weight to be worth it if there is

[flauge]

Last time I checked LTE had duals... for around 700 something tho.:eek:

[440challenger]

I work at a shop, and install all kinds of exhaust combos on 400exs.

The recent ones...
HMF slip on with stock header.
Full Sparks (not big core)
Full Procircuit T4

all on stock motors,no lid with dynojet kit.

For the money,you cant beat the hmf slip on.
Sparks, was all top end power,good for a motocross setup.
The PC T4 was amazing power everywhere. I couldnt believe it. Very impressive.

I have a full yosh on my girls 400 and its all top end, really dont like it imo.

[Hondamaster5505]

Originally posted by 07trx400ex
i am also looking at the duncan racing fat boy 2 does anyone have any experience with that and also is there a dual exhaust available for the 400 and does it add too much weight to be worth it if there is

The Duncan exhaust is almost exactly like the DMC.

The only difference is instead of going straight duals all the way back like the DMC, they go together right before the can.

[07trx400ex]

Thanks 440 challenger that was very helpful, but do you know if the sparks was x4 or x6 and how did the

hmf compare to the t4 strait up not counting price i am not really looking at the prices right now just tryin to figure out what system to get and then see if i can get a good deal on it

[07trx400ex]

ok nevermind the last post i think i have decided to go with the fmf t4 or ti4 whichever i can find the best deal on and has anyone tried the new fmf exhaust yet , but please anyone with the t4 or ti4 let me know how it is i am getting it because of the header seams to be the best and low to mid power seems to be the best but would someone in the know please let me know what the best header for scavenging the gases is that is also mainly producing low to mid power

[440challenger]

the fmf power bomb header is great but the muffler ..blows!

[07trx400ex]

so would you suggest for maximum gains the fmf header with maybe a hmh muffler or what would you run for max low end torque i am in tight trial never over 3rd gear but performance is still very big deal i always want to beat my buddies and get the most out of anything i buy

[08400EX]

Originally posted by 07trx400ex
so would you suggest for maximum gains the fmf header with maybe a hmh muffler or what would you run for max low end torque i am in tight trial never over 3rd gear but performance is still very big deal i always want to beat my buddies and get the most out of anything i buy

Big Gun Race Series will work great with the FMF header. plus I heard rumors of a nice one in great condition on Ebay right now, very cheap
http://forums.rennlist.com/rennforums/graemlins/icon107.gif

:devil:

[07trx400ex]

thnks man lol iwll definately look into that

[07trx400ex]

i think i am just going to copy your modlist since you seem to have this thing figured out 08400ex (by far the best info i have gotten so far)

nah i am going to try to add my own style to my bike i just want to get the most out of every part to keep up with my buddies even though i already can.....

in the tight technical stuff its more about the driver anyway but i guess i should get skids nerfs first anyway so i can keep myself and my machine protected first
and now after riding some more i think i might even try to do something about the &^^# front shocks that seem to enjoy bottoming out so it might be awhile before i get to upgrade my exhaust/intake

Thanks for all the help guys i really appreciated those that pitched in and still any advice not just limited to the topic is appreciated

i am really starting to enjoy this forum