[joshbrz]

Hi all, was hoping someone could explain or shed some knowledge on my current situation. Recently installed an HKS GTIII-RS turbo kit on my 2015 BRZ. The wastegate spring is at 12psi which is high for stock engines but I know that boost isn’t what kills our engines, it’s the torque. The kit works on stock motors but can also be paired with HKS stroker kit.

Car is tuned on 94octane, making 300whp and 240tq. The tuner was able to bring psi down to 10psi by adjusting preload, set boost cut at 15psi so it doesn’t creep and also set rev limiter to 6500. I also asked to keep the torque low in the lower rpms. Support mods include oil cooler, vented hood, clutch, pcv catch can, boost/oil press/afr gauges. Stock engine, stock injectors and fuel pump. Car does not get tracked just daily and some spirited driving.

My concern is that the car does build boost up to 15psi on the kit, then cuts at 15. I know I’m not making a whole lot of torque early on, however I am worried for knock due to the compression + high boost.

Is 15psi peak boost on 94oct a bit much? Or does it really come down to tune/torque?

Thanks!