turbo exhaust size please help

OK a buddy of mine is an idiot & hes too lazy to reseach for himslef but he claims to be getting a GS-X/GS-T...being 16 w/ no job...he obviously has little money he is planning to have a custom exhaust made & he was wondering if he should use 2.5" piping or 3". Im pretty sure he should use 3" being a turbo car & all but he would like to be sure. thanx a lot....sorry for the long post..thought i should rip him up a lil bit first. thanx again....

If he plans on getting around 350hp or more out of it, I would say 3". But if he isnt then 2.5" is fine

What does he plan to do to the car?

say it with me now "FOR A TURBO, 3.0 IS THE WAY TO GO"

Please don't make your simple generalizations. Up to about 350-400 horsepower, you really won't be able to tell the difference between a 2.5 inch and a 3 inch piping. And 2.5 inch exhausts generally sound better in my opinion.

Go with the 3 in diameter if its turbo plus with 3 inches he could use the spray more efficiently.

He'll be pissed later on down the road if he doesn't get a true 3" exhaust off the start. Now I"m starting to feel restriced w/ my full 2.5" exhaust.

Rob