I am building a custom turbo kit and the maf will be post turbo. I was wondering if it really matters if the bov is before or after the intercooler. I have a buddy with a honda and his in mounted directly on the intercooler

 

IMO, it really doesn't matter.

 

wouldn't you need two if you put them before the intercooler on a twin snails setup? e.g. one for each pipe between the turbo and I/C...

 

only if you have 2 throttle bodies

 

mines on the IC as well

 

guess I'll put it between the intercooler and tb, I was told the closer it is to the turbo the louder it will be and I want to keep the noise down.

thanks for the input guys

 

from dynos tons of cars and noticing how hot the air is that blows out of the BOVs... i originally put mine before the intercooler... figuring there must be some negligible gain in efficiency by blowing off hot air rather than air already passed through the intercooler.

that said, this time around im going to be running much higher boost. so I will be putting them closer to the throttle body for faster response... i dont want to be one of the unfortunate souls to have a throttle shaft snap, running plate screws thru the engine (havent seen it with the VQ yet, probably because very few VQs run high boost)... but in other communities, while rare, it does happen.

there is a big *** pressure surge at the throttle plate when you close throttle under boost, combined with immediate vacuum in the intake manifold... creating a rather powerful pressure differential that can snap a throttle shaft on large or poor designed throttles.

 

Try recirc?