Im doing a swap and was wondering what the stock turbo exhaust size is.....?

I was under the impression it was 2.5" but i keep seeing 3" exhaust all around. even if i put on 3" exhaust whats the benefit of the 3" after the Ypipe (downpipe on), I don't plan on replacing the Ypipe at the moment.

I don't plan for more then 310hp out of the motor.

so should i get 2.5" or go 3"? keep in mind once again i don't want more then 310hp

2 and 3/4.
problem solved.

I would go with the y-pipe replacement though and go 3" all the way. The stock Y-pipe really kills the boost (1+psi) at least. and the engine rev's so high that 3" piping is much more benificial (few hp). hope this helps.

know any place that sell the ypipe cheep?

935motorsports.com sells a 1JZGTE Downpipe/Y Pipe Combo for $279.00