done a search but couldnt find an answer, thinking of getting a custom exhaust for my s3 somepoint next yr, but im wondering what would be best, turbo or cat back and 2.5"-3" diameter? not sure, the power i wont to achieve eventually would be arount 400bhp give or take but that wont be done straight away will be over the next few years, so whats your thoughts
cheers
Iain
cheers
Iain