I say go with 11lb...reason for, my boi ran a 9lb in his SI and for some odd unknown reason after raggin it out for about 2 months or so, the damn teeth came off the flywheel, maybe because its too light and weak, dunno. But an unsprung clutch doesn't necessarily mean you're gonna snap axles, its just really harsh, you can always go with 4puck or 6puck sprung. ACT makes sum good ass clutches, or have you ever tried centerforce dual friction?