To add to this thread. I did the HPFP. My tuner is not into pushing the stock block too far even with a waiver so 28psi is the max. It feels strong. I haven’t been able to track it yet, but I would say 115mph traps. Roll raced a 2020 M3 and I pulled on him slightly until 140ish and they trap 114-117 at my local track stage 1.
Low end torque is excellent. I have gobs of torque at 2500rpm if I want it. I never floor it that low, but part throttle will pull u through low speed turns when you’re feeling too lazy to downshift. I was mistaken with my E30 tune no HPFP. I was seeing high 26psi not 28. I would love to see what 31psi feels like. I find leaving stock TC on makes the torque steer manageable in the 1st three gears and still allows some hooliganish shenanigans with the wheel spin and exhaust pops. AP TC kills all wheel spin 1st, 2nd, 3rd and gives the best 60ft. I have no LSD.