Which makes the 450r run faster on top speed

 

my pick would be pro-circuit simply because i dont like FMF on 4stroke quads, imo FMF is more of a successfull 2 stroke pipe company, but who knows i could be wrong.

 

id pick the procirciut, a buddy of mine had an fmf on his raptor and it flow so **** when he went to rejet it it was to much of a difference and had to put the factory jets back in to get it to run right.

 

I own the same bike and their is no top speed gain in putting on an exhaust maybe one or two but an exhaust is just so the engine breaths better and which will help with acceleration if you want to increase top speed changing gearing but i don't reccomend it

 

yup, pipe will let you get to top speed faster. It won't provide you anymore top speed than you already have.

 

i will go with 91warrior. also what koopa said it wont change your top just get you there faster. but still pro circuit will give you more hp and sound better than fmf. happy trails