BOV , boost leak, no power

[foxsdesignz]

im trying to find out why my car has no ass in it,, the timing is perfect, i check the CAS and is lines up,, i been told to do a boost leak test, but a friend was looking at the BOV and said it was the problem, he said it is letting air out at idle, now, it should be open until pressure different in the manifold it will close, so at idle it should be open, right?

 

[DSMunknown]

Right. Hope you're recirculating that air back into the intake.

BLT FTW.

 

[DSM_PWR]

So air should be let out?

My type s lower nipple blows air out during idle and when i boost leak test the car, you can hear/feel air coming out of the bov (not just the nipple but the part thats suppost to recirculate)... So thats a leaky bov right?

 

[DSMunknown]

When you're performing a boost leak test, there should be no (immediate) air coming out of anywhere. When the car is idling, there will be air coming out of the BOV (that's normal). The boost leak test is mimicking the compressed air under load when the car is running. Under load, the BOV should be closed. Of course, when doing a BLT the air will slowly leak down, but you should not hear hissing or see the pressure gauge go down rapidly. If there is hissing, or the pressure is decreasing rapidly, then you have a boost leak. And that's when you break out the soapy water.

 

[DSMunknown]

So air should be let out?

My type s lower nipple blows air out during idle and when i boost leak test the car, you can hear/feel air coming out of the bov (not just the nipple but the part thats suppost to recirculate)... So thats a leaky bov right?

I would check your diaphragm inside the Greddy. Look through this thread for more info.

 

[foxsdesignz]

but what if the BOV stays open even under a load, like there is not a good vacuum connection on the manifold,

 

[DSMunknown]

but what if the BOV stays open even under a load, like there is not a good vacuum connection on the manifold,

I have this problem with my Forge RV. Usually when this happens it's because of (at least) one of several reasons: the spring is not properly tensioned, the piston is not seating/sealing properly against the inside of the BOV, there is not enough lubrication between the piston and inner BOV wall, or (for whatever reason) there is too much vacuum in the intake manifold plenum that is not releasing the BOV piston.

I still haven't figured it out myself. I think mine has some sort of design flaw. I'll get around to sending it back to Forge for a replacement, it's just not at the top of my "To Do" list.

 

[Black_Bullet]

I have this problem with my Forge RV. Usually when this happens it's because of (at least) one of several reasons: the spring is not properly tensioned, the piston is not seating/sealing properly against the inside of the BOV, there is not enough lubrication between the piston and inner BOV wall, or (for whatever reason) there is too much vacuum in the intake manifold plenum that is not releasing the BOV piston.

I still haven't figured it out myself. I think mine has some sort of design flaw. I'll get around to sending it back to Forge for a replacement, it's just not at the top of my "To Do" list.

I bought a forge bov and had the notorious seal leak at the flange, sent it back and got another ( revised version ) now no more oring seal leak, but with the yellow spring it pretty much did exactly what you just mentioned in your post. It would have a slight pressure lose at any psi which was pretty annoying. During a boost leak test, cuffing my hand on the valve would build up enough pressure that when I removed my hand after about 6 seconds or so youd hear a puff of air lift with your hand. It may seem miniscule, but when your trying to get every ounce of performance it all adds up, especially on a little 16g like mines when your boosting so high that the turbo is dropping boost in no time needing every bit of air it can hold onto to maintain a decent psi to redline...

Next step, I run the blue spring now with 1 shim to try to see if it somewhat forces the value to stay closed... Well under boost it holds now till 20psi before I can start placing my hand over the valve and getting the pressure lose. I would add another shim to get it to hold more but then its just going to start compressor surging in the upper gears from being too tight. it already surges a bit now in 5th gear on partial throttle when building boost and modulating the gas.... I run up to 24psi by the way which the blue spring is suppose to handle fine.
Lose, Lose...

I mean vented ( blow thru setup ) the forge sounds awesome, one of the best valves Ive heard and not an overly dramatic tone or woosh. It looks great, and Forge is a decent company thats easy to deal with and great customer service; and the bov is a good price...
Hopefully no one else will have my issues with this bov... My final resort is simply get another bov.
Towards the end of the year I am going to give that new Tial Q a shot....

 

[DSMunknown]

http://www.dsmtuners.com/forums/pro...holding-open-wot-could-result-boost-leak.html

 

[Black_Bullet]

http://www.dsmtuners.com/forums/pro...holding-open-wot-could-result-boost-leak.html

Thanks DSM Link...I mean Unknown.

 

[DSMunknown]

When I finally do figure out the issue with it, I'll post up my findings.

 

[Black_Bullet]

When I finally do figure out the issue with it, I'll post up my findings.

Just read your whole thread, Ive already tried the greese, they sent me a packet of that, Ive tried new shims, new pistons, new springs, etc. Didnt change anything.

I run a lot more boost than you do ( well at least more than mentioned in your thread)
and I basically leak after 20psi with how I have it set right now... But unfortantly that is with the blue spring which is ment to hold well over 20psi. It also has one shim.
I believe that something with the diaphram is not sealing correctly allowing pressure from the IM that goes into the bov's top *( I call it the bov's hat ) portion of the valve to slip down the side and go out of the valve... I dont think its the air pressing on the bottom of it from the intake pipe. Just my theory though, if that made sense.

If you figure anything out post, I never hear too many ppl complaining about them so maybe its not a common problem. I am still going to change valves though, this thing has been headaches, I mean it works now and sounds good, but I am more of a perfectionist, and even if the amount of air leaking after 20psi isnt negligable to alter/ effect HP, spool, top end or anything, I still want to know that i dont have any leaks from it...
Tial is the only valve I know of that is pretty much the shit when it comes to bov's, and since Im running a gm maft in blow thru now, I can vent no problem.

 

[Eclipsemblue]

i dont think its possible for ## bov to leak at idle unless the spring tension is so loose the vacuum of the motor is pulling the bov up, i do not forsee your bov being your problem your car just might suffer from phantom knock where the timming is getting retarted. do you have a boost gauge in your car? and does it build up pressure/boost but feel like its going nowhere?

 

[foxsdesignz]

yeah,, it will make boost, but it doesnt make any power,.. i think what im going to do is make a video,, because a friend told me to check fuel pressure, becuase under a load, it will all must act like a fuel cut and back fire like theres no tomorrow,it will not do it if im under 50mph, anything higher and it starts acting up. but will that ### it to run really slow,,