Tial BOV open at idle

[Hiitman]

Bought a Tial bov that now stays open at idle. Is this a problem that a stiffer spring can fix or would adjusting the BISS screw and TPS be the solution? I'll have to check later on, but I want to say that my idle is around -11hg. Also, running the 7psi spring in the bov.

 

[hediki12]

use the 11psi spring

 

[jjrock5]

Is checking the engine vacuum the only way to check if the Tial is open at idle?

 

[snowborder714]

You should just be able to look at the bov and see if it's open.

Swapping in a stiffer spring should be an easy test and won't take long at all.

 

[okm12346]

what's so weird about that? At idle you have -20 hg/inch at the manifold - well that some serious vacuum there. And where's the BOV line connected to - the intake manifold, so there's vacuum applied to the BOV so it is open. When you hit the gas the BOV closes immediately and when you let off the gas, there's vacuum applied again so it opens and lets all the air out...making the cool sound.

 

[badas93tsi]

On an SD car it's no big deal, but on a MAF car, that is a big source of unmetered air. Get the stiffer spring and be done with it. It takes all of 5 minutes to swap them out.

 

[JusMX141]

At idle the throttle plate is 100% closed but the turbo is still spinning. If the BOV is closed, where do you expect the small amount of airflow the compressor wheel is generating to go?

 

[snowborder714]

At idle the throttle plate is 100% closed but the turbo is still spinning.

100% closed, but not perfectly sealed. There's still a very tiny bit of space between the plate and the wall that some air can pass by.

 

[okm12346]

On an SD car it's no big deal, but on a MAF car, that is a big source of unmetered air. Get the stiffer spring and be done with it. It takes all of 5 minutes to swap them out.

Yeah, that's why the BOVs are recirculated, not vented. You need to have the BOV before the MAF and use GM MAF + MAFT to achieve this.

But why are we discussing this, I thought this was common knowledge

 

[andy4g63]

The Tial BOV should be CLOSED at idle, period.. If you give it a little gas , then opens and closes again... Otherwise you do not have the right spring inside... If your vacuum it's about 11in/Hg, you have to use the black spring, which rated@7PSI and is for vacuum between 10-13in/Hg...

 

[redyute1]

I got the tial Q always open at idle,i've tried a stiffer spring but i got compressor surge.I run jackal sd so i switch back to my softer spring and let her stay open at idle,doesn't affect me cause i ran sd.

 

[talonalex92]

I got the tial Q always open at idle,i've tried a stiffer spring but i got compressor surge.I run jackal sd so i switch back to my softer spring and let her stay open at idle,doesn't affect me cause i ran sd.

Ditto. Not the q tho, just the standard tial 50mm.

 

[9!'clipseDOHC]

I'm having the same issue. Tial 50mm BOV. With the black spring the bov is open at idle and I get occasional idle surge but it functions perfectly under boost. If I move up to the unpainted spring it stays clossed at idle and the idle surge goes away but it won't open at low to mid boost and I get compressor surge. I'm going to swap back to the black spring, but I was wondering if anyone has figured out a way to keep it closed at idle with the softer spring.

 

[turboglenn]

damn do the tials not have the adjustent screw on top for dialing this in like most others do/ I don't own one myself and can't remember from the last time i saw my buddies

 

[9!'clipseDOHC]

damn do the tials not have the adjustent screw on top for dialing this in like most others do/ I don't own one myself and can't remember from the last time i saw my buddies

No adjustment screw (although that would be nice). They are only adjustable by swapping the springs. I think I am going to try shimming the black spring with a large washer.

 

[9!'clipseDOHC]

Just to update this, the black spring shimmed with three washers made it perform perfectly. No idle issues and it opens perfectly under low and high boost.