Exhaust system for a supercharged car..
 

So turbos will perform better with larger diameter exhaust pipes, right?

What about superchargers? UEL or EL headers? 2.5" or 3"? Catted or not?

Pre FI there are 3 great things you can do in this respect.

Quality air filter: ie: k&n, trd, etc that will give a gain on stock inlet box. Second a header and tune. Research that wisely as with TC you may not even use a header, but with SC yes pick away so you'll need to firm which route you go. Tune yes that's going to go far to, again research a tuner to.

Exhaust: guys have setup either way and 2.5" is plenty for sure even up to 350HP. Over pipe, front pipe and cat backs all offer "abit" but more for sound and looks to.

Disclaimer: I'm not an expert but I am a forum whore and listen to experienced folks.

Hope that helps.

You'll want a bigger, better flowing exhaust if you go FI for sure. It's more important with a turbo since they operate off of pressure differential in the exhaust, but superchargers like to breathe too. General rule of thumb is 2.5" up to 300whp, 3.0" above that. 4" if you're a bit nuts and have a really big turbo on a built motor.

Curious what people's thoughts are on supercharging with header, 2.5" overpipe, 3" front pipe, and 3" catback?

This is an interesting topic from Bob at Drift Office regarding headers on a S/C car.

http://www.ft86club.com/forums/showthread.php?t=47101

Good quality EL headers for better power.

The 3" piping will help with the FI exhaust flow.

A cat will help dampen the sound of the exhaust, so that's a personal choice.