Q for those with BOV's

[fiater]

Just curious - those using BOVs - are you keeping the wastgate actuator function? You only need one or the other, right? If you remove the WG actuator, are you getting better spool times between shifts? I'm converting to TII shortly and was wondering.

[shelbyplaya]

you need both. The WG is the thing that helps deterin how fast the turbo spools. The BOV dumps excess intake pressure (when the TB closes) from reaching the compresser and suddenly stopping the turbo from spinning.

[Marcus86GLHS]

FIATER the two items have totally seperate and different functions, you dont necessarily require a bov, but all turbochargers require a wastegate actuation system.

[impuresoul2k3]

I would(and do) run a BOV and will on any turbo car I have in the future. Why have compressor surge?

[fiater]

I thought the WG let the exhaust bypass the turbine, therefore slowing it down/reducing pressure in the intake. Is there another function? I don't remember a WG on my Evo, but then again never dug that far into it. I just thought the BOV and the WG served the same function, just on different sides of the loop.

[88shadowpjct]

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

[Miss89baron]

Quote:

Originally Posted by 88shadowpjct 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

Which BOV is best for no leaks and good discharge at 24 psi 2.5" pipes? HKS, RFL, Tial, others ?

[88shadowpjct]

i dont know about the other bov's but im running a turboxs RFL (im only at 15psi now) and they say they've used them up to 35 psi. so for those its just washers/spring stiffness for holding high boost.. the others, someone else here might know and have more experience with them.