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Tial BOV issue

Discussion in 'The Blower Bistro' started by Blinkwow74, Sep 1, 2019.

  1. Blinkwow74

    Blinkwow74 Member Established Member

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    looking for some assistance here....
    2011 mustang gt with a Paxton 2200SL installed with all the various things also attached.
    I had the car tuned about 5 days ago and everything was running great. Then a day ago I started losing power and all I could hear was the woosh sound you hear when you normally let off the gas back when it was running normal.
    So I pulled the bumper off then figured I check all my t-band clamps on every coupling. All were still tight and no holes present. So I started my car and at idle seen my tial BOV was open which it should be because of the vacuum. When I shut the car off it closes as it should. But when I rev up the rpm alll I hear it the woooshing sound. Had a friend come over and he confirmed it was staying open as I went from 3k - 5k.
    So I took off the BOV (not fun gaining access by the way after everything is installed) and checked it out. Both O-rings were still in tact. And so was the bladder but I guess that’s obvious since it was opening up at idle. Also the Green spring was present and intact. I put the lightest of coats of CLP gun cleaning oil and preservative on the oring think maybe it was just sticking in the open position.
    I reinstalled everything back to how it was and still I’m getting the same results.
    I disconnected my boost gauge from the system as well (sealed the open end of the t-fitting) to perhaps count that out as a bad actor. Same results... if it matters yes I’m hooked off the line coming from the brake booster per the install instructions.

    Any suggestions? My tuner is wondering what I did and did nothing. I haven’t even raced it since he did the tune.

    Update I disconnected the brake booster and connected the line straight to the bov... to eliminate the possibility I had a leak in my brake booster diaphragm. Still same issue.
     
    Last edited: Sep 1, 2019
  2. slo984now

    slo984now AKA 01yellerCobra Established Member

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    Just revving it isn't going to close the BOV. It needs to hit 0 vacuum which it needs a load to do. You could've hook up a vacuum pump and see if it holds. Are you not making any boost at all?
     
  3. Blinkwow74

    Blinkwow74 Member Established Member

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    None it’s going to atmosphere through the bov... I drove it a few minutes ago with the brake booster disconnected.... and still doing the same....
     
  4. Blinkwow74

    Blinkwow74 Member Established Member

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    At idle
     

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  5. Blinkwow74

    Blinkwow74 Member Established Member

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    On the road with a load on the engine... constantly lunging.... and BOV woooshing
     

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  6. PC03GT

    PC03GT Well-Known Member Established Member

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  7. 1996MysticSnake

    1996MysticSnake Active Member Established Member

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    Isn't the supercharger spring pink?

    Pretty sure that's what's in mine. Also that pic of your boost gauge while driving, your barely at 0 vac, the bov should still be slightly open.

    Sent from my Pixel 3 XL using Tapatalk
     
  8. Blinkwow74

    Blinkwow74 Member Established Member

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    I was at 5k
    The spring is green for the bov’s Made after 2012
     
  9. Blinkwow74

    Blinkwow74 Member Established Member

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    When i get back from the hurricane evac I’ll give that a try
     
  10. PC03GT

    PC03GT Well-Known Member Established Member

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    Good luck and be safe out there
     
  11. slo984now

    slo984now AKA 01yellerCobra Established Member

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    For whatever reason I can't watch the video. When you say load were you at WOT or just hanging it at part throttle?
     
  12. Blinkwow74

    Blinkwow74 Member Established Member

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    So I got a reply from Tial pasted below. I’ve really already done all of this so I will be replying with my sn#. But it shows that even without a load the bob will close of functioning correctly as you rev the engine and you are at -4.1hg or less. Mine is staying wide open he entire time. Until the motor is shut off. Haven’t gotten around to trying to swap out to the original one that came with the kit. Doesn’t look like that is going to be a fun process disconnecting and attaching the old


    Hi, George,

    For the Q-Series, the 'green' spring is what we recommend for supercharger applications, as the initial opening rating is very low (-2psi), so that the BOV remains open at idle and at part throttle, anytime engine negative pressure is greater than that rating.

    This means that, any time engine vacuum is greater than the spring rating (-2psi, or -4.1inHG), the valve will be open.

    This is perfectly normal for supercharged applications, and is actually required by the supercharger manufacturers, as the BOV is acting as a bypass, so that positive pressure does not create tuning or mechanical problems at idle and low speed.

    We do not recommend using a 'tee' or another device in line with the BOV. We recommend a 1/4" inner-diameter, reinforced hose or tube, routed directly from intake manifold pressure, downstream of the throttle, directly to the BOV, for best response

    The first thing we would recommend is to simply test the BOV, and you can use a hand vacuum pump, and the instructions here, to do so: http://tialsport.com/documents/BOV Static Testing.pdf

    If the BOV passes this testing, and you have it routed directly to the manifold as described above, the BOV will be open at idle, but any time that intake manifold pressure increases to a rate more positive than the negative rating of the spring (any intake manifold pressure greater than -2psi), the valve will then be forced closed by the spring group and the force of the engine intake manifold pressure applied to the diaphragm.

    One way to confirm this would be to put a temporary tee in place, close to the BOV, and monitor exactly what you see for negative and positive pressure, and watch the valve. With a supercharged car, this can be done with the hood up and the transmission in Park, as the supercharger will build pressure even with no engine load. If you see the pressure rise above the spring pack, and the BOV closes, then stays closed until you decelerate, it's working exactly as it is designed to.

    If it's functioning correctly, and it's just a simple matter of changing the opening rate with a stiffer spring, this is perfectly acceptable, as long as you don't select a spring that would force the valve close at idle. If that's an option you want to explore, I would probably recommend taking a reading of engine vacuum, right at the BOV hose, at idle, then we can discuss the best choice for you.

    If the BOV does not pass the testing, please send a clear photo of the top cover, showing the serial number, so that I can research further.

    Best Regards,

    Mike Franke
    Tech Support
    TiAL Sport
    E- [email protected]
    W- tialsport.com
    P- 989-494-7268



    On Mon, Sep 2, 2019 at 1:19 AM TiAL Sport <[email protected]> wrote:
    Somebody sent you an email using the contact form on your website. This is what he entered:

    Name: George Charette
    Email: [email protected]
    Message: Hello,
    I have Tial Q50mm BOV for my 2011 Paxton 2200SL setup. It was tuned on Aug 28 and everything was working fine. But now I’m constantly hearing the woooshing sound at idle and at throttle... my boost gauge won’t go above zero. When I’m at idle my boost gauge shows -20 when I accelerate its lunging and obviously not boosting because all I hear is air even when I goto 5k rpm.
    I have checked all my couplings and they are all tight as well as the t-fitting coming off the brake booster for the 1/4 tubing that goes to the Bov.
    I checked the BOV and the diaphragm is in tact and as well as both o-rings. I have the green spring installed as well.
    One other thing I did try bypassing the break booster and connecting the bov straight to the hose coming off the manifold. Tried it on a empty secluded street since my brakes wouldn’t be working as well. Still the bov valve opens as idle like it should but then nothing but wooshing sound all through acceleration and I never actually go into boost. Any thoughts?
     
  13. geoffmt

    geoffmt Well-Known Member Established Member

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    Do you have a solenoid for a boost gauge? I’m running into similar issues as you with no boost but mine is maxing out at about 4 pounds I may have junk in the solenoids or some small debris that’s keeping it stuck open. I’ll look into that more this weekend on my end but just a thought


    Sent from my iPhone using svtperformance.com
     
  14. Blinkwow74

    Blinkwow74 Member Established Member

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    Na it’s a direct pressure type gauge.
     
  15. Blinkwow74

    Blinkwow74 Member Established Member

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    So I did the test with the vacuum hand pump. The tial bov unseats at -4hg at approx -10hg it’s fully seated to the top.
    As I release the vacuum it starts to release and is just barely open at -4hg.

    So currently confused why it doesn’t even move when I press on the gas. My boost gauge shows I’m at just under 0hg but the valve stays fully seated as though its at -10hg or greater vacuum.

    It weird because if I had a vacuum leak you’d think the valve would easily close shut.

    So my thoughts on this are. Once I accelerate to a point that it’s less than -4hg vacuum the bov should shut. The positive pressure from the supercharger is now filling the intake manifold. Where part of that positive pressure makes its way through the vacuum line to the diaphragm in the tial bov to make sure there is more pressure pushing the bov shut plus the 2psi spring. Then when you let off the gas there is a vacuum created and the valve is immediately opened to release that positive pressure to atmosphere.

    So what would cause the bov valve to maintain vacuum enough to remain fully seated in the bov valve in the open position. Even when at less than -4hg damm near zero

    My car friends are equally confused
     
    Last edited: Sep 12, 2019
  16. DSG2003Mach1

    DSG2003Mach1 Well-Known Member Premium Member Established Member

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    Vacuum line getting pinched or something? That’s odd
     
  17. Blinkwow74

    Blinkwow74 Member Established Member

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    Everything is fine and the individual line is not kinked nor obstructed...
     
    Last edited: Sep 13, 2019
  18. geoffmt

    geoffmt Well-Known Member Established Member

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    Do you have another blow off valve you can swap it with to see if it repeats?


    Sent from my iPhone using svtperformance.com
     
  19. slo984now

    slo984now AKA 01yellerCobra Established Member

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    It sounds like the BOV is never seeing boost. Have you tried a different location to hook it up? I tapped mine into the FRPS on my old set up. I'm assuming your car has one of course.
     
  20. DSG2003Mach1

    DSG2003Mach1 Well-Known Member Premium Member Established Member

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    I think you're right.

    1) did it ever make boost after leaving the dyno?
    2) has anyone seen the boost gauge show boost and not just vacuum at any time?

    Im wondering if the shop put something inline to log boost and mixed something up. I don't know how the vacuum for the brake booster setup works on your car but my thought being its only seeing vacuum. If you could post pics of where the vacuum line from the valve is T'd in you might get some help.

    I deleted my EGR and tapped a vacuum fitting into that to run to the valve
     

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