Mustang and Ford Performance Forums banner

american racing headers

  1. 2007 - 2014 Shelby GT500 Mustang
    This weekend I was working the dyno at the NMRA event in Reynolds GA. Decided to stick my car on the dyno because we were kinda slow. I was curious to see how the 3" exhaust, and ARH headers had helped my car out because I noticed a big seat of the pants difference in the upper RPMs. A little...