HEADS UP!!!

Site upgrade in progress... Core site functions are working, but some non-critical features/functions will be temporarily unavailable while we work to restore them over the next couple of weeks.

Please post any bugs you encounter, but before you do, check to see if it's already listed.

Thanks for your patience while we work to improve the community.

Sign in to follow this  
Followers 0
timothypg

high flow header/ loss of torque?

7 posts in this topic

86 xr600r. need a new header. i have heard a higher flowing pipe will reduce low end torque, is this true? fmf has one that say's it will increase low to mid power. any thoughts? tim . i have after market ex. already. wileyco.

Share this post


Link to post
Share on other sites

The higher flowing exhaust will have less restriction, so you will lose the backpressure required for low and mid torque. The top end will be noticeably more powerful though. I have an FMF Q full system, and it has a portion of the midpipe that looks like a small expansion chamber. They call it the PowerBomb. I'm guessing this is the one youre talking about. I am not sure how much torque it gives, because I had my engine rebuilt (overbored) and carbs jetted at the same time I put the exhaust on. Let us know what else you find!

ANdy

Share this post


Link to post
Share on other sites

I have the powerbomb header and powercore4 (650L)- great low end and gain throughout. It's better across the board now. way more on the bottom - lug down and pulls...

good luck!

rob

Share this post


Link to post
Share on other sites

i just ordered a stock head pipe from xr's only/ceramic coating. i wanted to stick with oem size. they said a couple weeks, hope it works out.

Share this post


Link to post
Share on other sites

I have the hi-flow headers with FMF PC IV and thought it was too loud. The bike had tons of torque throughout, but definitely had a lot of top end. I put the FMF quiet insert (baffle basically) in there and noticed a gain in low end. I'm guessing because of the back pressure. Bike is nearly as quiet as stock now and I think it actually runs better. The jetting my have been just a tad lean as every now and then at low elevation I get popping on the decel. Now it seems right on. Who knew a baffle would actually make the bike run better.... I like to take it out every now and then (mostly around town or private property) just to let her scream, and I'll admit it even though I firmly believe in being quiet.... it sounds awesome.

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

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0