blow off valve location

ok, i have looked at many cars w/ turbos. i have a friend running a t-66 turbo (i think) on a supra and he has 2 sequential BOV's. one is before the intercooler and the other is just before the throttle body. why does it help to have 2? my second question is this. i know that most people only use one BOV when running it on their cars (like most hondas/acuras). does it really matter where the BOV is placed? will placing it in a certain place ("x" many inches from the throttle body) affect how it performs? any help will be greatly appreciated.

Does he have the twin turbo setup? T-66 is pretty big....You can damage your IC at different boost levels...that maybe why they did that. Placement is on the intake part of the system....nothing specific that i can find. I wouldnt have it directly bolted to your TB though.

lol...i know it wouldnt be bolted directly to the TB...i may be a newb to this board, but i'm not a newb to cars...lol. naw, he has a single turbo set-up. i think the engine is fully built cause he had it dyno'd at 660 HP @ 24 psi (that is without the clutch kit he needs which is $2k). thanks for your help. also, one more question if you dont mind...do BOV affect performance? i know what they do and what they are for, but i was wondering if they are actually performance adders. thanks again in advance for your support.

|ps| does turbonetics make custom turbo manifolds? i have an accord, but i have been looking at selling that and purchasing an Acura Vigor because of the ability for luxury and the get-up-and-go. it is a 5 cyl. thanks again for whatever you can do to help me out.

ok the people that have two BOV are ussally running really high boost to get the air out faster and i heard that it is better to have the BOV before the intercooler. I heard this off another and this guy know his stuff about turbos so i will try to find why it is better

this is why

The farther away the BOV is away from the TB, the better. This is because when the throttle plate opens up again there will be less lag because there will already be some boost in the charge pipes.