Talked to a guy that used to be on drag racing team that competed in a lot of events around here. He installed my exhaust system.He said that on the cars they used to race (american muscle not imports) they used 1.5 to 2 inch tubing for their race cars. Why so small?My only guess was that they probably dont use cats, or mufflers so the smaller tubing gave them enough backpressure for the engine to run properly. Am i right, its been on my mind for awhile, I used 3 inch on my truck.
The primary tubes on the headers would be 1.5 to 2 inches, the collectors most of the time about 3 inches. That's the way way drag car exhausts have been made forever.
yeah, that's the reason why. with no backpressure, torque off the line sucks.