Exhaust System Upgrade

I have and original exhaust system on my 92 twin turbo. What is an ideal pipping 2.5" or 3" twin exhaust ? Or is it better to go single from cat back ???

3" is stock, and good enough for most applications. You just need a high flow at the end, and why not get new piping while your at it. Im doing a single outlet, less weight and same flow. But do what works for you, single outlet looks funny with the bumper we have.

keep your double single won't be any faster if you do your exhaust right, just make sure you keep the 3" piping.

single exit will weight less, so it will technically be faster.