i got a fully built gsr motor with 720 cc injectors, 10.1:1 je pistons. bore is 81.25 mm (darton sleeves), extrude hone b18 head, skunk2 intake manifold (port match), itr throttle body, motec m4 standalone, and thermal 3" exhaust. i was wondering which turbo best fit my motor. my goal is to make 500+ whp street driven if its possible. the car is going to be street and drag.

 

Do you mean B18c head? Just curious. But I think you can make 500 with either turbo. The T4 will make you wait for boost a little longer but would actually support over 500 whp if you like. Just my .02. Looks like you have a pretty solid setup regardless of which you choose.

-Ryan