Exhaust Performance...

[Maryland 400EX]

I just bought a '99 400 EX from a friend and was given a Dirt Wheels Magazine to go with it. In an article in Dirt Wheels Magazine, it was stated that in the March '01 test of exhausts for the 400 EX, there was only ONE pipe that made more horsepower (1 more hp) than the factory exhaust. If this is true then why is everybody buying exhausts? For the noise? The factory 400 EX exhaust must be a free flowing unit to compete with the aftermarket companies in terms of horsepower even with it's rough inner welds.

[exriderdude]

i thought it was like 4 or 5 horse increase. i think it was the CT pipe and WB E-Series. the 400's stock pipe is pretty free flowing. if you put a pipe on a raptor it gives it like 13 more horse, cuz it is so restricted.:D

[VegasEx'r]

I never read that article, but I do know that the shootout for the Raptor pipes they did a few months ago had some flaws, so I wouldn't be suprised if that was the case here, too. I know that there were hills I had problems climbing when my quad was stock, and after I put on the Big Gun exhaust (along with rejetting & a K&N), I was able to get up those hills with little/no problem. Also, as you do more mods to your motor, like raise the CR or displacement, or switch the cam, an aftermarket exhaust will help more.

[Sick0]

The pros of an after market pipe.
They make more power (1.5hp)
They are lighter
They look alot cooler
They have a better sound
And When you start doing motor mods It make a bigger diffance.

I was dissappointed to find out my pipe only makes about 1.5 horse but I'm happy I but it. You can feel thew diffance.

[Maryland 400EX]

1.5 HP? Damn. I happen to ride in an area that would be best suited for minimal noise output from this Quad so I may just start off with a set of 39MM Keihins and a 14 tooth sprocket instead.

[MadcapEX]

I may just start off with a set of 39MM Keihins and a 14 tooth sprocket instead. [/B][/QUOTE]

You must be a Yamaha turncoat, hondas only use one thank G. By the way,where do you ride??

[nakomis0]

I always heard with the 400ex (and all 4stroke quads), is just get a slip-on exhaust. Unless you plan to do motor work, than ya will want a full.

[Maryland 400EX]

Yamaha turncoat? Not hardly. What I am is a long time streetbike racer that happened to have a slight interest in quads. I may have said "Set of Keihins" because I've had a set of 41's on an R1 in the past and forgot that this motor features only one carb. I ride in Upper Marlboro and the Clinton areas.