People really sleep on the small turbine S300s. They're not intended to make gobs of power but their response is insane. That's why I'm hoping the gated housing allows me to spray it and not send the compressor wheel into the intercooler haha.
From running the S300 (362/68)on a 8.3L Cummins, there isn't much adjustment to lower the boost point much below 40psi. You'll have to make a longer female part to lower spring tension to open sooner.