Tial BOV open at idle?

[Khadaw66]

I just installed a Tial Q BOV and noticed that it stays wide open on idle. Once I disconnect the vacuum line, it shuts close. It is still getting the stock vacuum from the intake manifold. I am also running a GM MAF post BOV. It currently has a 8 lb spring in there. I couldn't find a topic regarding this issue on the forums. Do I need to upgrade to a higher spring? Thanks for looking and I'm sorry if this is a newbie post. Thanks.

 

[scott90gsx420]

Well I'm really not to informed about this but Ive read a couple threads so IL tell you it sounds like you need to adjust the spring in it. Its way to soft im guessing if you tighten it that will bring more resistance making it harder to open.

 

[crazyquik22023]

You need to get the spring that matches your vacuum. Here is the springs you should use for different vacuum levels from Tial's website.

0 to -7 in/HG use 3 PSI Spring (Pink)
-8 to -11 in/HG use 6 PSI Spring (Black)
-12 to -15 in/HG use 8 PSI Spring (White)
-16 to -19 in/HG use 10 PSI Spring (Silver)
-20 to -21 in/HG use 11 PSI Spring (Purple)

 

[scott90gsx420]

You need to get the spring that matches your vacuum. Here is the springs you should use for different vacuum levels from Tial's website.

0 to -7 in/HG use 3 PSI Spring (Pink)
-8 to -11 in/HG use 6 PSI Spring (Black)
-12 to -15 in/HG use 8 PSI Spring (White)
-16 to -19 in/HG use 10 PSI Spring (Silver)
-20 to -21 in/HG use 11 PSI Spring (Purple)

Ha thanks for saving me i have the stock 1g bov so idk about these things.

 

[JusMX141]

You want it to be open a little at idle- that's the idea of a blow off valve or compressor bypass valve....when recirculated, the system goes into a closed loop when the throttle plate is 100% closed at idle so the small amount of airflow the turbo is generating has somewhere to go.

Choose the spring based on the amount of vacuum your engine draws- too little spring tension will allow the valve to hang way open, too much will not allow the valve to open properly...leading to compressor surge which will eventually damage the turbo.

 

[Khadaw66]

Thanks for all the replies guys. I will order the 10 and 11 lb spring to be safe since my idle is anywhere from 19-22. Thanks.

 

[redyute1]

I got the q too ,she stay open at idle i have tried matching my engine vac with the right spring, but all i ended getting is compressor surge,so i said f !!! It cause i ran sd so it dont matter anyway. The good thing is it shuts soon as you hit the throttle.

 

[TWOpointFORliter]

Bringing this thread back because I just installed my tial and I am having the same issue. I understand the point Justin made about it staying open. However it just doesn't seem right that it is sucking in unfiltered air into the system. Are you absolutely sure it should be open at idle?

 

[JusMX141]

When I say open, I mean open slightly- not wide open. At idle the turbo should still be making more airflow than the engine is using, so no air should ever be "sucked into" the valve.

 

[TWOpointFORliter]

I'd say my BOV is open less than a 1/4" at idle. I'll have to double check when I get home but I swear it was pulling air in nit pushing it out. I am still on the stock 2g maf and was hoping to drive it up to get SD installed and a tune, but I guess it will have to be loaded on a trailer since it doesnt run well enough to make the hour drive with it being open at idle.