what brian here is tryin to say is you want velocity to push the exhaust out of the car

you dont need "backpressure"

 

This has gotten out of hand. SEARCH!

This has been all posted about.

Backpressure isn't what you are looking for, you want the right size of piping to keep the exhaust velocity up. Make it too big and the gasses will be slow in exiting, make it too small and there's too much pressure and a loss of power.

There is a BIG thread about it in these forums, with a BIG sticky and all sorts of good links.

CLOSED.