Alright, I've been searching for the elusive boost leak that I'm experiencing for some time now. While driving home from work today, I noticed that I hear my BOV constantly going (a buttefly flapping sound is how I've always described it). It's making this noise while I'm on the gas...and quits when I let up. When I got home, I popped the hood and revved it and it just constantly makes this noise. This is probably my boost leak right? I always thought the BOV functioned when boost was built up and throttle ceased...like shifting or letting off the gas altogether. It's not supposed to be leaking boost into the atmosphere while I'm on the gas right?

Have I found my leak!!!?

Thanks,
Dave

 

This can happen at partial throttle sometimes. If you build up boost, say 1-2 psi of boost (which is only like 20% throttle) and then you go back to 10% throttle, there is still a surge of pressure that the BOV will release. Usually it makes it in the fasion that you described because it is so little pressure, and the engine is bleeding off the pressure slowly as well.

If you are in the throttle and it's making this noise then there is definetly a problem. I would check your vacuum lines running to the BOV. Make sure it's a fairly direct line to the other side of the throttle body. If you examine the left side (driver's side) of the intake manifold there is a little line for a vac line right behind the throttle body which is used for exhaust gas recirculation. I disabled that crap, and ran my BOV line from there.... It was very responsive. Also make sure the line is big enough, I think Tial uses 1/4" vac line.

If all thise fails, go buy a Tial BOV and be done with it, they work very well.

Chris

 

What kind of BOV is it? With the Greddy Type S I had, you could adjust the stiffness of the spring. Maybe your spring is just too loose.

 

It's a Tial BOV.

I'm heading off to work (overslept a little) and I'll take a look at the vacuum line tomorrow morning.

Thanks for the response!
Dave

 

All the vacuum lines are good.

ok, I'm pretty sure there is a malfuntion with my BOV. From what I can tell, this Tial BOV is not adjustable...they don't just make BOV that handle only 6psi of boost correct? No matter what size pulley I put on my SC, it only get 5.7 psi max boost. Does anyone have any recommendations for a good BOV? I'm usually not concerned with the sound of the BOV, but I'm tired of this whimpy butterfly sound. I'd like to at least go with the PSHHHH noise...at least it's a little more intimidating. Anyone have any recommendations? It's going on a Comptech SC with front mount intercooler...the SC has a 3.5" pulley on it that'll push who knows how many psi since I can't seem to get above 5.7. Any recommendations would be greatly appreciative...especially if you have a link to it. The one I have now is constantly leaking...even WOT I can hear it.

Thanks!
Dave

 

I think it would bo better to jus change your BOV, cause youre running to little boost for that BOV.
Most TIAL bov are to handle a lot more boost that your'e running.
They say it's from 0 to 30 psi, but most of the time it begins at 7 psi and up.
Or you should change the spring in that BOV.

 

any recommendations? The searches I've done on BOV's rarely say 7psi-30 or whatever like you say. I don't want to buy another one with the same problem. And I'd really like to get away from this butterfly flapping sound that mine makes. I don't know if that's a result of how much pressure they're releasing or not, but if I can get one that sounds a little more aggressive, that would be great.

Thanks again,
Dave

 

I loved my Greddy Type S, and it was adjustable. However, it's strange to me that the Tial you have is non-adjustable. And by more agressive, if you mean louder, I'd go with the Turbo XS RFL.

Johnny

 

alright, will the BOV work for me if it says it's made for 10 - 25 psi of boost? I'm not really sure what i'll be running with the 3.5" pulley. Will I have to adjust it when I get it? I'm not really sure how all this works. I'm looking at the Turbo XS RFL.

Thanks,
Dave

 

Not sure how much boost you'll see with a 3.5" pulley, I'm really not that familiar with superchargers. But adjusting BOV's are pretty easy, especially if you're running minimum boost levels. So pretty much adjust to as loose as possible.

Johnny