Story is as old as gtps. Guy adds headers car goes slower...
7 years ago I walked all over this sh!t talking kid who didnt like the tune I put on his car.... he had jesus tune it for $500 and it was a 3.4 headers setup. I called him out to my stock hai 97gtp and took him to the cleaners dig and roll.
The problem I find is the headers have exhaust leaks or cause the o2 sensor to read lean due to it being in a different location. This then adds tons of fuel and you go slower. Ive made header cars gp faster than stock manifold cars but you better have a trick tune and a tiny pulley if you actually want to see gains consistently.
