I about spent alot of money on one of these turbos ! and your input would ease my mind ! i have a ITR block with JE 9.8:1 pistons 81.50 mm,eagle rods,ITR cams,Blox Intake manifold, stock ITR flywheel shaved off 6lbs,act clutch and pressure plate,880 cc injectors, walbro 255 fuel pump, equal length turbo manifold (off-name brand)! my goal is 550-650 whp! with full boost by 3500-4500 rpms! i have no rev limit but i used to shift the stock type-r motor at 9600-9800 rpm ! also which rear ar. ? .63 or .70 or .81 ?

 

SC61 is your best bet if you want full boost that early. you might not even get that with the sc61 though, but for sure you won't have it that early with the SC63 or T3/67.

650 whp is also a lofty goal with your parts list.

 

thats a lot of hp youre asking for with your parts list. sc61 is a good turbo but you might want to rethink your setup or hp goal

 

I dont think your going to hit full boost by 4500rmps on any those turbos and support upto 650whp. do get me wrong those turbos are capable of 650 just not fully spooled by 4500. I had a SC-61 and I loved it. There a plenty of post on here with those turbos. most of the post on here with those turbos has there setups and a dyno sheet, so you can look at the dyno and see when they hit full boost and how they spool. You can make you judgement from that. just my .02