I've got a 180 with rb20det and hks2530 @14psi, soft suspension, pineapples, fairly decent 225/50/16 tyres and i will break traction above 4500-5000rpm in 2nd, consistently. I'd say i've got a fair bit less weight over the rear wheels compared to r32s and r33s though. Hopefully i'll be able to get a pair of RT215s on another pair of rims to use on particular occasions, but having them as daily tyres just isn't financially viable.