I noticed alot of FAST racers use the Ultra-Flows so thats why I looked at them and liked them. So I use the Ultra-Flows with a 3" X-pipe system out to the rear bumper. I always race thru the pipes as I never uncap it so I really dont know if it slows the car any. Ron

Last edited by 383man; 03/12/12 10:45 PM.