Exhaust for Stage 1 cam???

[MtnEX]

Hey fella's my team mate did a stage 1 cam in his XC quad which is otherwise stock.

What do you all recommend for that cam? Just a slip on and stock header? Or do you go to full exhaust for that?

I wasn't sure what to recommend. We race XC.

[CJM]

HMF slip on Id say. Cant really gain much over the stock header even with an aftermarket.

[MtnEX]

So at what point is the header beneficial?

I did not know any better when I bought and did a full Yoshimura.
Sounds SO good... but that is about it really.

I think most of the benefit was at the muffler.

[CJM]

Theproblem is due to the nature of the design the header really cant be improved upon too much. Would a slightly larger diameter help-maybe but its questionable really for the price a slip on costs vs a full exhaust.

I got a slip on and been super happy.

[2001400exrida]

the sparks full system really opens the 400ex's up. slip ons will give you some great sound and might add 1 hp or 2, but the sparks full system can produce more power with lid off and a good cam.

[Stickman400]

Your making the power from the open lid and cam in combination with the exhaust. The difference between a slip-on and a full system isn't going to be noticable if all you do is jet for it.

[CJM]

Originally posted by 2001400exrida
the sparks full system really opens the 400ex's up. slip ons will give you some great sound and might add 1 hp or 2, but the sparks full system can produce more power with lid off and a good cam.

right, go ahead chime in and tell the guy to spend on a 500+ dollars exhaust to gain 1 whole hp at most.

Go back to the org.

[DragonGunner]

If you build big on your EX, like a 460 stroker and going for top end then a bigger header would help.......I would stick with stock, I did get a deal on a full CT Racing system, but still wasn't worth the money for the header that only lasted a few years, wasn't stainless. White Brothers E series is a great slip on, dirt wheels did dyno testing back in the day for slip ons an it came in first....been running mine about 12 years an still like it. Take the money you save on a header an use it for a port job on the intakes, and a clean up on the exhaust side. And or a high compression piston.

[ish416]

When I stepped up to the FMF Powerbomb header from the stock one, I didn't notice much of a difference besides there seemed to be more mid and top end. Not a major improvement but maybe 1 or 2 horsepower. Also noticed the exhaust was a little bit quieter. I would say unless your running a 416 + with 11:1 or higher compression you likely won't see any noticeable improvement over the stock header.

As for slip-ons, here is a list of them that I have personal experience with:

The WB E-series was the best. However, it is no longer made.

The HMF are good for power but I personally think they sound terrible and have seen to many fail (broken welds, blown packing, wallered out endcap bolts) within the first year. Of 12 people that I personally know that purchased one of their exhausts, only 3 still have them.

I really enjoyed my FMF Powercore 4. Great tone, noticeable power gains (tons of torque) and held up great. I would still have it, had I not been offered $250 for it after several years of use. However, they are expensive.

Motoworks SR4 is in my opinion the best system for the money. Solid gains, good build quality and a good sound for only $210 brand new. This is what I will be purchasing when my WB E-series dies, which will likely be sometime this coming year.

The Yoshimura slip-on is basically the same as the Motoworks but at over twice the price. Not worth it.

[hondaREX]

I have no experience with aftermarket 4 stroke exhausts. Ive been planning a build to one extent or another for this winter and an exhaust was somewhere in the build. My first choice was the Motoworks slip-on, great price and the best reviews. I already grinded the stock header welds. But along the way ive seen the CT and Sparks and loved them both. Not too many out there, so not many reviews, those that did had good things to say for both. I bumped into a Sparks X6 full stainless on here that i had to have. Figured i could tone it down with an insert and get an arrester for it and Id be under $300, why not. So i got it. When i got it, it was just awesome. Just felt and looked bada**!! Had a minor crack at a mount weld that i had tig welded for free. Started the bike with it on and MAN was it loud and sounded sick!! I have only been around a couple different makes and this was the best i heard. Just idled the bike on a stand for few minutes. I think the quiet insert "might" get me in the area of 98dbs, hopefully. But i ride with a couple 450r dirtbikes that are plain loud, so i should be good. State laws and atv patrols around me are pretty strict. Ill post when i do get the inserts to update what i think and how loud it is.

[RNL]

Let us know how it goes.

[JOHNDOE83]

A hollowed out slipon and ground header welds on the stock header is better or just as good as any full system you can buy.

[RNL]

Originally posted by hondaREX
I have no experience with aftermarket 4 stroke exhausts. Ive been planning a build to one extent or another for this winter and an exhaust was somewhere in the build. My first choice was the Motoworks slip-on, great price and the best reviews. I already grinded the stock header welds. But along the way ive seen the CT and Sparks and loved them both. Not too many out there, so not many reviews, those that did had good things to say for both. I bumped into a Sparks X6 full stainless on here that i had to have. Figured i could tone it down with an insert and get an arrester for it and Id be under $300, why not. So i got it. When i got it, it was just awesome. Just felt and looked bada**!! Had a minor crack at a mount weld that i had tig welded for free. Started the bike with it on and MAN was it loud and sounded sick!! I have only been around a couple different makes and this was the best i heard. Just idled the bike on a stand for few minutes. I think the quiet insert "might" get me in the area of 98dbs, hopefully. But i ride with a couple 450r dirtbikes that are plain loud, so i should be good. State laws and atv patrols around me are pretty strict. Ill post when i do get the inserts to update what i think and how loud it is.



Sparks racing says there is a loss of power with the quiet tip. Be interesting to see how much it tones it down.

[MtnEX]

I think I will recommend a slip on to him and grinding the header welds then...

The SR4 G2 ,,,is that a full system or slip on?

[ish416]

The SR4-G2 is not available for the 400EX.

The SR4 is available as a slip-on or full exhaust.

http://www.motoworksstore.com/

[MtnEX]

I think it is going to be an HMF slipon, UNI and EHS lid to go with the stage 1 cam.

Now to figure out what jets to recommend he pick up.

I am going to suggest a 40 and a 42 pilot.
I think everyone should have those on hand.

HMF's jetting suggestions look WAYYYY to rich to me.
165-170? (just for the slip on)

I was thinking 152-158 for it before considering the cam which I was thinking would not make a huge difference in jetting.