Jump to content
Sign in to follow this  

PRO Exhaust trick?

Recommended Posts

Can anyone tell me what the deal is with the canister that is attached to the head pipe on alot of the PRO's bikes? I am thinking it has more to do with sound reduction than a power adder but i dont know.

Share this post


Link to post
Share on other sites

Are you talking about the muffler or the smaller device such as the one that FMF manufactures? It mounts between the header and the midpipe and does in fact increase performance (so they claim) and has nothing to do with reducing the exhaust noise. Also a well designed canister (muffler) can reduce the exhaust noise while increasing the performance of the vehicle.

Share this post


Link to post
Share on other sites

IMO, that FMF "bomb" exhaust is a marketing gimmick and doesn't do anything, but that is just my opinion. If it did improve power, everyone would have it.

On a 4 stroke engine, the best exhaust is one with clean, smooth bends and little restriction.

Share this post


Link to post
Share on other sites

in a recent issue of dirt wheels, it showed joe byrds and a few other pro bikes that had what appeared to be a soda can sized canister welded to the head pipe. it wasnt part of the headpipe like the powerbomb, it was attached to the pipe on top of the headpipe. i will see if i can find the pics online and post one.

Share this post


Link to post
Share on other sites
IMO, that FMF "bomb" exhaust is a marketing gimmick and doesn't do anything, but that is just my opinion. If it did improve power, everyone would have it.

On a 4 stroke engine, the best exhaust is one with clean, smooth bends and little restriction.

If it is just a "gimmick", why is everybody copying it....and risking getting sued by FMF because they own the patent on the technology?????

Share this post


Link to post
Share on other sites
in a recent issue of dirt wheels, it showed joe byrds and a few other pro bikes that had what appeared to be a soda can sized canister welded to the head pipe. it wasnt part of the headpipe like the powerbomb, it was attached to the pipe on top of the headpipe. i will see if i can find the pics online and post one.

I have been running bombs since the first day they came out!!!

These "cans" are just a way to attempt to get around FMF's patents. While FMF could sue them, they consider it a form of flattery to have their technology coppied by all the wanna bees.....

It is common knowledge that a longer header increases low end power, for a varienty of reasons. The purpose of the "bomb" is to give you the effect of a longer header (without any actual extra length), without losing any top end. It also has the added effect of cooling the exhaust and decreasing noise.

Share this post


Link to post
Share on other sites
If it is just a "gimmick", why is everybody copying it....and risking getting sued by FMF because they own the patent on the technology?????

IDK, but greed comes to mind. If something is selling more than the rest because of a gimmick, then why wouldn't anyone want to copy it and join in on the increased sales?

I'd love to see a dyno sheet prove that it offers any substancial performance gains. I could be wrong and it won't be the first or last time, but if proven wrong, I still benefit because I learned something new. :bonk:

Share this post


Link to post
Share on other sites

All it allegedly does is affect the reversion waves that affect back flow into the cylinder through the open exhaust valve and out the open intake valve during overlap. This only occurs in a narrow rpm range on a four stroke. There is little to no sound attenuation by this device. Look at the massive expansion chambers on two strokes. If the expansion chamber reduced the exhaust noise, two strokes wouldn't be any louder than a "weed eater".

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×