BOV

[aspect]

Putting a check valve on the bov return line lets it idle normally and vent to atmosphere on shifts. At idle, air coming through the bov isn't necessary.

MK

well, it allows the engine to draw air from in front of the turbo, because at low rpm the turbo is basically just an intake restrictor. although, I really can't see this making a huge difference to the accelleration of the car...

[mTk]

If there is a way to get it to vent back into the untake below the 6-7psi then that would work nicely i would think.

MK

[TurboLegacy]

my car is all fixed and running great. i am running 10psi and about 180hp at the fly. i found a way to get the blow off valve sound without making the car run terrible. I mad a small hole on the top of the rubber bypass hose which brings air back to the intake tube. then i used a round file and made it a little bigger. i bought a small brass coolant drain hose from autozone for 2.99. it has a nut which can open and close the hole inside it. i put the valve in the tube and secured it with some zip ties ( my best friends) and opened it all the way. i kept taking test drives to get the pitch and length i wanted. i had the valve almost fully closed so it would make a high pitched longer sound.because the valve lets so little air out, the maf doesnt get messed up and my car runs the same as when i didnt have the valve on. the sound isnt very loud, but it is audible inside and outside the car( just enough to let everyone know im drivin a subaru turbo). if u do try this and your car does run bad, you can just close the valve all the way and run your car normal. i am very pleased with my little modification and recommed it to anyone who wants that sound but doesnt want to spend a lot of money on a bypass/blow off valve, and dont want to sacrifice performance. the way i have it set up allows most of the air to be recirculated and a little to be vented. the small brass valve lets the small amount of air be amplified alittle. a pvc valve would prolly sound different. well thats all im going to do for my bov needs, unless i get a greddy bov so that it doesnt leak at 1/4 throttle like the stock bypass.

[one2free]

so.. does the bov leak during idle??
HKS claims that it wont leak "under high boost conditions nor under vacuum at idle"

[TurboLegacy]

our stock bypass valve leaks alot usually at partial throttle but not under full boost, i dont think it really matters if it leaks during idle