Common question, need an honest opinion though

[400exrapes]

yes i know youve all heard this question many times before. But, I need a good answer from an honest person to tell me, What is the best slip-on and header exhaust for a 400ex that will soon have a K&n air filter with no other engine mods? if your going to help me out please give me your opinion on what wont hurt my top end but give me a much better acceleration. I know half of the people to answer this will recommend their own pipe but i want the best pipe money isnt excactly an issue but nothing ridoulus. Thanks for the help

[JDMThoughts]

Use the search function, there is a dyno comparison on the dyno forum of the HMF slip on producing more power than another 400EX with a Full White Brothers. HMF is probably the way to go, it seems to be the most popular one out there. A lot of people on the forums seem to love their slip on.

[troutman561]

Ill second the hmf even tho I have an fmf...

[400exrapes]

i want more acceleration not that the 400ex doesnt have excellent acceleration already i need to be able to beat all the other 400 sportsd like the kfx and ltz, so i need good acceleration because most of the race will jsutbe the holeshot in the beginning on the trails and then onceim ahead its done. I've set my eyes mostly on
1.Yoshimura Rs-3
2.Pro Circuit T4
3.Fmf Powercore 4
4.White brothers E-Series
If anyone has any experiance with those let me know, yes the hmf's are great but my friend has a d.g. pipe the excact replica of an hmf and it is ear peircing ridiculously loud and thats not what i want i want a pretty descently loud pipe just a little louder then stock and good performance, the best performance for the money ill probably buy a k&n air filter with a power lid and precharger relative to when i buy the exhaust and with a dyno jet kit.

[troutman561]

Well I have the fmf, some people dont like it but I think its pretty good, but it has gains all around the rpm range insted of just a concentration on low end. I havnt been around any 400ex noticeably faster than mine... I would steer clear of the white bros,my friend has one on his and not such good construction with them and I dont like the sound of them and I think they are more of a mid range pipe(im not 100% on that tho). But out of those choices id say the yoshi pipe.....

[JDMThoughts]

Out of all your choices, Yoshimura is the best one to go with. I don't think the HMF slip on with baffle is all that loud at all. Perhaps the one without the baffle is really loud, but I really think the HMF sounds the best out of all of the ones on the market.

[400exrapes]

oh yes i love the osund of the hmf i described it as loud in a bad way because my neighbors... they dont excactly like the loudness they dontlike atv's at all so a good performance pipe that isnt waking up the neighborhood would be cool umm about how loud is the yoshimura pipe compared to the stock?

[Trask27]

HMF for sure
and f you go thru Chapperal they will hook u u with a god deal too
The polished chrome is a nice touch
You will not regret it hope noise isnt a problem:macho

[jrm03]

I had the Powercore 4. Its has minimal gains throughout but sounds great. I now have the HMF and am very pleased with it. If you are set on those pipes, I'd go with the Yoshi.

[poorboy]

to be honest with you I have gone threw 3 different pipes now. the moose bub which gave alright gains but for me I have the yoshimura header and slip on and I love it. really. It does not sound as good as the moose but it works alot better and it an easy set up. They run for about 400 and change. Also you may want to re jet your carb when you upgrade to a header, I had to.

[400exridin121]

The yoshi is good, but if money isnt a concern a curtis sparks is great, i have an x-4 on my stock 400 and it gives you awesome accel and great power

[quadman 05400ex]

YOSH slip all the way it daa bomb

[400exrapes]

great i think its gonna be the yoshimura rs3 slip on and if i have enough money the full rs3 comp series system... now if anyone has any online sotres that give a really good deal for the rs3 slip that would be great if you can show me that also quadman05400ex how loud is the pipe compared to the stock because i cant be wakin the neighborhood up when i ride by and is it spark arrested