Which BOV is best for no leaks and good discharge at 24 psi 2.5" pipes? HKS, RFL, Tial, others ?the WG shuts sending your exhast through the exhaust turbine of your turbo. when it reaches your set boost level, it opens and the exhaust bypasses the turbine so it doesnt KEEP building boost. some will still flow through to keep that level there. when you let off the throttle, the throttle plate closes and the pressure between the throttle body and turbo increases because this compressed air has nowhere to go (even though the turbo is slowing down, its still spinning and pushing some air) this causes the air to try to exit BACK through the turbo because its the only way out, suddenly stopping the turbine giving that flutter sound (aka compressor surge). so the WG controls the total boost and your BOV stops compressor surge.
you definately need the wategate and you should have a BOV