i currently have 2.25 piping. Will that be enough for running boost or is it a MUST to go up to 2.5...for a 2200
will i see a much better gain with the 2.5 though?
depends on how much boost man. if you are running 8 or above i'd personally recommend 2.5" all the way back. no cat, run a 24" resonator to keep it quiet. and you'll get a lot of low end power.
I was a retard, and now I'm permanently banned.
would a bigger exhaust housing make a difference?
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Kick azz is my boost hero!!! 
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with a turbo you want the biggest exhaust you can fit under the car. small piping has nothing to do with low end power in a turbo car. the turbine housing and wheel are big restrictions in the exhaust. with bigger piping there will be less backpressure on the wheel so that it'll spool quicker. the quicker it spools, the more low end power you'll have. i'm going 3" without a cat myself.
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450WHP Turbo Ecotec swap in the works...
