Installing FMF Exhaust and Powerbomb

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Active Member
Mar 9, 2005
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Frederick, Maryland
The powerbomb manifold is a no brainer but the exhaust is a little strange. The muffler is connected to the mid pipe with these two springs. Is there any need for high temp silicone or anything else at this section. I know that where the header and the mid pipe connect they suggest high temp silicone. Also they have one hanger that goes around the exhaust and bolts to the frame. They have another clamp that looks like it is for joining the mid pipe to the manifold. What is that funny looking bolt with the big spacer on it for?

Thanks :-/
Ok well since I am impatient I called FMF. They do recommend high temp silicone at both locations where the mid pipe enters the exhaust and where the mid pipe connects to the header. The funny bolt with the spacer is in case you need to space the exhaust away from the frame where you clamp the muffler. This exhaust also eliminate one of the mounting positions so it is only held in place by the one bracket instead of two like the stock exhaust. I may take pictures tonight in case anyone thinks this will be useful.

It does two things. Yes it reduces the sound, not why I got it, but in the cooling and expanding process it actually speeds up the flow of exhaust hence increasing performance.

The redesigned PowerBomb is a four-stroke header that incorporates FMF's patented PowerBomb module at a precise location in the initial stage of the header. By positioning this "Bomb" at a key point in the system, increased performance and flow is achieved through the expansion and contraction of exhaust sonics through the system. Result is a flow increase of nearly 10%! The outer chamber in the Powerbomb allows the air to expand, cool and ramp back up at a higher velocity.

Additionally, the PowerBomb is a "pre-muffler" of sorts which helps to lower the bikes sound output by providing more sound absorbing surface area for the sound medium (exhaust gases). On some models, you can choose between a moto or supercross version. The supercross version is designed for more low to mid-range power where the moto version is focused in the mid to upper RPM range.