Hey guys,
I was just wondering what the best placement for my BOV would be. Im going to be running a S5 turbo (for now) on a 13B-RE using a NPR front mount.

I seem them mounted by the turbo and sometimes by the TB, but never really figured out if one spot was better than the other. Its a Blitz SSBOV if it matters.

 

i would believe the closest to the turbo outlet is the best area as far as funtionality..... it alows for the air closest to the turbo to be let loose which is the whole point to prevent compressor surge... that is where mine is mounded

 

Thats what I thought too, but then I wondered why I see so many right by the TB elbow.

 

It is best mounted in a spot that is low-velocity / high-pressure when the throttle closes. This means either near the turbo or near the throttle body. If you are going to recirculate the air with a bypass valve, then near the turbo is usually better to reduce the plumbing length. If venting to the atmosphere, then I don't think it matters whether it's near the turbo or throttle body. The higher velocity area in the middle of the pipe isn't as good, but you also need to consider where the BOV will physically fit under the hood, so sometimes you need to put it in a less than optimal position.

 

my favorite's greddy type r

 

Best is closest to the tb. When the tb closes, the reverse pressure waves starts at the tb and travels back to the turbo, best to stop it close to the tb. Of course mine is mounted at the turbo outlet ... practical constraints.

 

my favorite's greddy type r

 

Thanks for the info guys. I wouldve liked the GReddy too, but I picked this one up for $100 on eBay. Not a bad deal.

I think im going to put it by the turbo, since we all know there is alot of free space there, and I dont want to screw up my pretty -RE elbow.

 

right up next to the throttle body, that way you dont backflow the air in the intercooler and IC piping. That was you also start to dump air pressure before it gets to a big spike. when i had it mounted just after the turbo, when i had the std I/C and turbo it would give a real loud PSSSH, now with it up next to the TB, ie: the BOV is approx 1 1/2 inches from the TB assembly, actually in the piece which i had fabricated to spread from 3 inch pipe to the triangular TB shape, all i get is a lighe pft pft pft. which i believe along with a lot of others means its doing a better job

 

I have mounted me bov mid way between the TB and the intercooler.

 

But I dont want a light puff puff puff, lol, I want a loud *** whoooooossshhh.

 

the light puff puff puff sounds very serious though, like the WRC cars etc. people hear it as apposed to the obnoxous PSSSH and think 'man thats car is serious' hahaha

 

Woulden't you think a puff puff puff would mean that the pressure waves are bouncing back and forth?

 

You should think about convenience for RnR (I had to remove the BOV to get to other parts in the engine bay) and what will fit in your car (older Greddy kits had the elbow in a very tight location making it hard to place the BOV close to the TB plates).

If your piping is routed fine with no/minimal leaks, then it shouldn't matter where you place the valve since it works by venting pressure. Like electricity, pressure will flow to the path of least resistance.

Unless you're racing at a highly competitive level, I wouldn't worry too much about placement as long as it's between the compressor outlet and TB inlet.

The fluttery sound you here is compressor surge. It varies on the type of BOV and spring setting. Typically, you'll get more of the whoosh sounds with a very light spring setting.
The "whoosh" varies in it's sound depending on the BOV design. I personally like the Xcess Type H (on my ol' FC) since it had a very smooth and nice whoosh to it. The Greddy (Type S on my FD) tends to chirp like a bird.

J