hey guys-im doing my first turbo setup-and i want to know what downpipe size i shoudl get. im going to be using a gt35r ball bearing turbo, tial 44mm wastegate, full race manifold, some sort of blow off valve, and a precision turbo monster intercooler. the block is darton sleeved, has low compression pistons, is bored out, and has eagle rods. anyway, i was curious on what size downpipe i should get. i currently have a 2.5in exhaust and high flow cat, but usuallly on turbos they sell 3inch. i can also get a 4inch downpipe, but what difference would that make? im thinking 3inch w/o cat and full exhaust would be great, but let me know

 

Go with a 3" downpipe thats big enough

 

Just go 3" turbo back...