Ok guys here is the big shootout everyone has been waiting for. This was done by Dirt Wheels and are slip on pipes with spark arrestors only, for a 400ex. Machine had airbox lid removed, K&N air filter and a 155 main jet (varied by pipe but most a 155).

Best peak HP:
1. White Bros. E-Series
2. CT Racing
3. Yoshimura RS-3
4. Pro Circuit T-4
5. Big Gun (standard core)
6. White Bros. R4
7. Graydon
8. Honda (stock pipe)
9. Stroker SX1
10. FMF Power Core
11. Big Gun (quite core)

Best bottom HP (4000rpm):
1. CT Racing
2. Pro Circuit T-4
3. Stroker SX1
4. Graydon
5. Yoshimura RS-3
6. Big Gun (standard core)
7. Big Gun (quite core)
8. White Bros. R-4
9. White Bros. E-Series (but highest at 3500rpm)
10. FMF Power Core
11. Honda (stock pipe)

Best overall:
White Brothers E-Series (produced the most power, had best finish, tunable, and was one the the quitest)

The White Bros. E-Series and the CT Racing tied for the most HP.

My comments:
I would recomend the CT Racing pipe for racing or competing because it is a high HP pipe but also the loudest and the most heavest of all the pipes. The White Bros. E-Series would be just as good and quiter though.

Don't even bother with the FMF Power Core. You should stick with your stock pipe if you were considering this pipe.

Oh and if ya didn't get this issue it was the March 2001 issue of Dirt Wheels.

yeah it really ticked me off that they ran them with the arrestors in
wanna know something interesting? in the next issue they test the Raptor and DS with FULL Graydon Proline exhausts WITHOUT the arrestors installed. and then they raved about how much better these quads were.
makes you wonder who's paying the rags off this month.

Is the spark arrester the reason the stock pipe almost made as much hp?I was suprised to see the biggest gain over stock was only like 3 hp.I guess you pick up some throttle response with the aftermarket pipes though.


moded out 86 trx250r
97 300ex
90 blaster

I would say no as far as the spark arrester being the reason for power loss. The spark arrester has little to no affect on power. It is mainly just a wire screen on most pipes.

I have the feb 01 issue(march issue not out yet) and they have the ds and raptor with proline pipes(no arrestor) and do rave about how much differnce they make. They do look nice to(red) would mach the 400 good

Me and my friend both have 400ex's and mine is stock and his has the E-series slip on. I beat him on the track becuase he said the E-series gave him no bottom end power at all. I think the biggun is the best even though it didnt rate to good . I have heard some pretty good stories about it in the past.

there's no dummy's at honda and its hard to beat honda's exhaust.if you go to gt thunder's web(www.geocities.com/gtthunder.geo)in the bench test/400ex they test a stock machine versus no airbox and this is without rejetting and a k&n.all that midrange gain wasn't the pipes,nor the dip before peak-do after market exhaust really out perform the stocker?the shoot out was biased(they should of tested the stocker with the same airbox/jetting/filter mod.all you really gain with a pipe is noise,pretty looks,less weight and an empty wallet-)a HIGHLY modified machine will gain more with a megaphone and bigger headpipes though)

i was wondering why they didn't have the dmc or duncan racing double barrel pipe

They did not run the DMC or the Duncan because they do not have spark arresters. All the pipes they tested had spark arresters on them and they were only testing pipes that had them.

hgow is the dmc?????