Originally Posted by urbansmoker1
The bigger the waste gate the more control you have over boost. I dont think you can go too big because its supposed to open at your maximum boost and relieve excess pressure if you boost over your set limit.
I'll go ahead and say this is *somewhat* true.
The bigger the wastegate, the more control you have over low
boost. The function of the gate is to open fully when your maximum boost level is reached, the slowly close as the RPM's climb and the engine gobbles up airflow. If the gate is too large, too much exhaust will continue to bypass the turbine wheel- and the boost level will trail off as the RPM's climb. If you attempt to combat this with stiffer springs, then the opening of the gate can be delayed and cause a sudden spike/drop in boost which makes tuning a nightmare.
These new giant 60mm wastegates are designed for high-displacement engines at very low boost levels. With a DSM at 30+psi, a 38mm gate is all you'll ever need.