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RuffRyder400ex
04-04-2003, 11:45 AM
Does anyone know anything about the fmf Q pipe. Does it give really any power? And how quiet it is?thanks
wilkin250r
04-04-2003, 12:07 PM
my girlfriend just put an FMF Q on her 400EX. It's not quite as loud as other pipes, but it's much louder than stock.

She gained bottom end, but lost top end. She's pissed. Now I have to sell it on ebay and buy her a new exhaust pipe.

I bet she'd sell it to you for a decent price. It's hardly used, it looks brand new.
RuffRyder400ex
04-04-2003, 12:14 PM
I am just lookin for what will give some power and different pipes to see what is the most quiet. Can you guys help?
wilkin250r
04-04-2003, 12:42 PM
Just a thought. If your looking for quiet, you can get a big-bore kit and keep the stock exhaust.

True, you won't perform AS good as a big bore and pipe combo, but I bet a big bore/stock exhaust would make more power AND be quieter than a stock bore/aftermarket exhaust.
RuffRyder400ex
04-04-2003, 12:59 PM
How well would a cam, jet kit and a air filter work on my 400? Would it add a lot of power?
wilkin250r
04-04-2003, 01:27 PM
Well, many people would disagree with me, but I don't recommend an aftermarket cam with stock exhaust. I can give you a full explanation if you'd like.
wilkin250r
04-04-2003, 01:43 PM
Valve timing is important to cam design (duh) but you need to understand where that comes from.

When exhaust gases flow out of the cylinder, they have inertia. This inertia can actually create a vacuum within the cylinder, which will help to pull in a fresh air/fuel mixture. This is called scavenging, and it happens when both intake and exhaust valves are open at the same time (overlap). The effect is greater at high RPMs. The point of this whole thing is that exhaust flow is very important to the perfomance you will see from an aftermarket cam. The cam design is based around an aftermarket exhaust, which has less restriction than stock exhaust. If the exhaust gases aren't moving as fast (because of restriction in the exhaust pipe) then you don't get the scavenging effect. In fact, you may not get rid of the exhaust gases completely before the intake valves open and you may actually push exhaust gases through the intake.

I would not recomend an aftermarket cam with the stock exhaust, you may actually lose performance.
RuffRyder400ex
04-04-2003, 01:49 PM
allright thanks for all of your help:)