Horsepower is only part of the equation. It becomes a problem sooner on engines when you try to run low boost on them than if running higher boost. High flow exhaust systems make them problematic sooner than those with more restriction. The size of the hole itself varies drastically turbo to turbo which of course effects its ability to bypass enough exhaust flow to control boost (this one can be fixed with porting to open up the hole and also to smooth entry into the hole by rounding the short side radius). There are also larger flappers available which allows you to open the hole up even larger. The other consideration is that some turbos are designed to use an internal gate (like BW EFR's) and therefore have housings cast in a way to facilitate flow through the gate while other turbos (like stock T3's and T3/T4's) they are more of an afterthought with a hole 90 degree to the direction of exhaust flow which is obviously less effective.
Last Edit: Jul 18, 2020 13:16:55 GMT -5 by Stinger