#17133, "RE: Turbo is now installed and runs right!!!" In response to In response to 10
Even if your downpipe is 2 1/4'', having a bigger exhaust is always better, expecially on a turbo car. Eventhough your downpipe would be a little of a bottleneck, making cat-back 2 1/2 or 3'' will free up the backpressure more than if you stuck with 2 1/4''.