it may start choking up around the 600rwhp mark. we had problems with .63 housings over 650rwhp/21psi on 98-octane. E85 will be even worse. with bigger housings we picked up around 50-70rwhp all the way thru. converter made a big difference also, went from 500ft-lbs to 680ft-lbs when going to a Neal Chance converter.
Your .63 housings were choking at 650whp on a twin turbo setup? I'm only running a single pte billet 6262, if I'm understanding what you're saying I'm even more confused. As I'd figured my single .58 would already be too small to handle the 4.0l of displacement.
I'm only planning on running 500-525whp as I don't want to push my luck on a completely on-opened motor (haven't even pulled the valvecovers) by looking at my current gains I'm hoping to hit my hp goal at only 12-13psi. Shouldn't be too hard as I'm already in the process of swapping to an r154 and only running 8psi right now (9psi wastegate spring, 8psi at intake or 1psi of pressure drop through intercooler)
i thought u had twins. they weren't choking bad till about 800rwhp (about 400hp each) the turbo's however were only rated to 550hp.
Great Job! Love the stance of the car and your setup. Did you gain any hp with the new intake manifold? Or did you run those numbers with the first dyno numbers? Have you weighed your car yet?
Keep up the great work bro.