BOV venting early, any suggestions/ideas?
 

Hey guys,

Recently installed a JDL turbo kit, having problems with my BOV venting wayyy too early. It seems to be building boost for 1,000 rpms or so...and just as I start getting into the powerband my BOV vents. It feels like being on a boat and the propeller shaft stalls. I have a 3 port boost solenoid that is plumbed as follows:
-Right Side/fitting#1 left alone/vta
-Top fitting/#3 goes to the barb on the cold side of my turbo
-Left side/Fitting #2 going to Lower Air port of Tial MVS wastegate

Vacuum source for the BOV is T'd from the brake booster line. I have confirmed that I am on the correct side of the check valve in the hose.

The wastegate is running a 7 PSI spring, and the BOV was running an 8 PSI spring...I swapped it out to a 12 PSI spring with the same results. I am very concerned at this point because my IAM is extremely low...in the 0.35 neighborhood. My mileage is low and I have never beaten on the car. Is it possible that because of the premature VTA that it could have caused my spark plugs to drastically wear due to exhaust gases not being able to meet the fuel being injected////big rich spikes? Idles like a champ and the low speed driveability is actually pretty good...although I can feel that the car is pulling back timing big time and it feels very sluggish. I am not able to hear any loud knocking or abnormal noises.

Please let me know if you have any suggestions or experience with the same issues I'm seeing. I'm running out of ideas and fear for the health of my car.

Are you sure it's the BOV and not the Wastegate? Sounds like a Wastegate issue to me.

Your tune cares what Springs you have in your BOV & Wastegate. Leave the 7psi WG spring in and install a small yellow in your BOV. The wastegate is the guy on your turbo header and your BOV is on you intake tube.

As of right now your BOV is unable to release pressure, it's to big. You can't just swap either or without tellING your tuner first.

BOV spring has nothing to do with tune... only thing that effects BOV spring consideration is idle vacuum.

The spring on the BOV is dependent on what is your idle vacuum. You're probably around -19 inHg vacuum so should be using either unpainted or yellow spring (I use the yellow spring). I see you've said you changed to the brown spring with the same results. It seems there is something wrongly installed.

You shouldn't be concerned about early BOV actuation causing any damage since it vents prior to the MAF sensor.

While the car is idling, is the BOV open? Also I'd check the BOV and WG are properly installed and have their O-rings properly installed (I can't remember if both have an O-ring).

http://www.full-race.com/store/image...-content-1.jpg

I am on a speed density tune so to my understanding it is not using MAF readings but rather preset values are input in place of the MAF. Before with the 8 PSI spring my BOV was open at idle, now with the 12 it is closed. I am positive that the O-Ring on my BOV is in place correctly, I honestly don't remember either if there was one on the wastegate. In regards to the low IAM, another thing I forgot to mention is that I had what I believe to be a Cam Angle Sensor wire touching my downpipe(which was wrapped). I've since threw a layer of electrical wire and gold foil around the wire that was touching.

I am currently using the Yellow/7.25 PSI spring in the wastegate. Initially my BOV came preassembled with an 8 PSI spring...JDL told me that due to the fact that it is so far from where it is reading vacuum that it would be fine. I switched to the 12 PSI spring because my tuner initially told me that was what he recommended.

Is it 100% on speed density or MAF for drivability and switches over to speed density at higher air velocity?

It's a weird issue for sure, can you clearly hear the BOV? I wonder if you have a boost leak and you are hearing the boost leak at whatever PSI it comes up...

It is a Delicious F&G, it is advertised as 100% SD....although MAF is one of the parameters he's having me log? The BOV is definitely venting...the sound with the 12 psi spring in now is unmistakable.


I took preemptive measures for boost leaks (clamped the evap hoses in back of the ac compressor, STI PCV Valve).

Speed density the maf shouldn't even be hooked up. Should be completely unplugged or running a block off plate with the wires going to the intake air temp sensor on the cold side.

Are you running an external waste gate or electronic boost controller ?

If the correct springs were installed I would check EVERWHERE for vacuum lines not being hooked up correctly of backwards. also are you sure it's the bov venting and not the waste gate dumping? Diaphragm in the waste gate could be damage. Like I said if all springs are correct I would check vacuum lines then check waste gate internals for damage.

May be different for your set up but my understand and what I have done in the past the waste gate spring should be set for half the psi of what you are wanting it to dump at so a 7lb Spring would dump at 14 psi

I was not aware of this, I just assumed that the MAF readings were ignored. I am using a Tial MVS External/Open Dump WG and a 3 port boost control solenoid. I am out of town at the moment, I plan on going back through everything when I get back. In regards to the O-Ring on the WG...I do remember there being a big orange one that seals the top and bottom half together. Should there be another one?

Just changed an external tial waste gate on a 15 Sti. There was just that orange diaphragm that seal it. If that gets damage it will leak. Also check ur gasket on the bov . If that has a leak it'll sound like blowing air under a loose piece of tape. As long as the tune is set for speed density then there should be no reason for the maf to be hooked up. Backwards vacuum lines can cause extremely high boost and the springs in your waste gate are the only thing saving u from over boosting and going boom.

Really double check that boost controller and make sure the lines are hooked up correctly going to the turbo/intake/and the waste gate.

As far as I know, the stock ECU does not do Speed Density, so Ecutek does a workaround for it, and it uses the MAF as a temperature reader as input into the VE calculation. So yes, the MAF is still used, just not as a MAF