Are you guys with the PMS able to vent the BOV into the atmosphere or do you recycle it back into the intake? I can't get the PMS to run the car very well at low RPM's (below 3000) and at idle possibly because I have a BOV venting to the atmosphere. I know the car runs like sh!t when venting to the atmosphere with only the stock ECU, so I'm hoping this is my problem, even though I was under the assumption that with the PMS I could vent to the atmosphere and the MAP sensor included with the PMS would allow it to run smoothly.

[This message has been edited by Armand Bonner (edited May 16, 2000).]

No, the MAS for the PMS still works the same way as the stock one. The air is counted before the turbo and anything you blow off from the valve is actually counted air, so the car will still stall or bog between shifts like a stock one would when you vent the BOV. If you want what you could try is to lean the idle setting a bit, and see if you can vent. For my car this kind of worked, but it was not perfect, the best solution I had was to get the Super Sequential from HKS, this allowed me to vent the atmosphere with no idle problems.

I've got a Blitz BOV. Is there any difference between the Blitz and HKS?

I am not 100% sure, so someone may need to correct me. The Blitz Blow-off is like many other valves, where it uses a spring in addition to boost on the diaphram side to keep the valve closed. When you let off or idle, there is vacuum present on the diaphram which will cause the car to hesitate or stall because the valve may be partially open. The HKS SSBOV works the opposite of this, the whole valve assembly is backwards. When the car is under boost, instead of boost working against the valve it is actually working for it, forcing it to close, and at idle, the vacuum does not pull the valve open.

Hmm,
I do have the Blitz Blow-off valve, and it is sequential. I've had not problems during shifting, but I did have the same problems at idle and at low rpm's.

I've since cured it by adjusting the fuel at idle to -10%, and as for the "bogginess" at low rpms, I set the accel snd to 2, and accel recv to 20. (Both in menu 900)

From what I've learned, I dont think that it is the BOV that gives the bogginess when using the PMS. It is the larger MAF that was meant for a V8, as opposed to our cars. The stock ecu is not compensating for, and that the PMS cannot adjust for at low rpm's. If you have an old PMS, there will be no accell feature in menu 900 as that was added after the first production. In that case, send it back and they will upgrade the chipset. If you do, fool around with the accel features, but 2/20 seems to be the best setting...

Try that, see if it works for you...

[This message has been edited by Alex Schulz (edited May 16, 2000).]

I hooked up the tube from the Blitz BOV back to the intake and instantly it ran like a new car. Doug from EFI systems told me that the tube must be hooked up to operate smoothly. At idle (vacuum), the valve is open and draws air through the valve and not through th MAS creating a lean condition as the ECU does not add fuel for this air. Even if you tune the PMS to compensate for the atmosphere venting, it will still run rich during shifts, making the car slower for a split second after mashing the gas after your shift. I think you would be able to vent to the atmosphere if it is possible to have the valve completely cloed during vacuum. I think I'll try to adjust it, because I like the pssst sound!

What I'm wondering is why no one has tried mounting the mass air meter AFTER the blow off valve. This would make everything so easy. The VPC is normally tapped into the TBE, why not stick a modded MAS in right before the TBE? That way you could have the BOV vented to the atmosphere with no problems and even a 3" cold air inlet from the stock I/C location (if you have a FMIC) and still retain the stock metering system. You could even run the turbo open-air on the track (no filter). The only defect I could see would be creating the mount for the honeycombs in the upper intercooler pipe. Anyone have any ideas why this wouldn't work?

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1992 Eagle Talon TSi AWD
BOOSTN on the flatlands

I don't think that would work because the air that is going through the MAS sensor is at atmospheric pressure. If the air was pressurized a variable amount (turbo) then there would be no way to determine the actual air going into the engine... that is unless the whole system was redesigned from the ground up (ECU etc...) by the factory. It would also have to have a MAP sensor to determine the pressure so that the actual air flowing into the engine could be derived from both the MAS reading and the intake pressure. It would be like having two systems, MAS and MAP.

[This message has been edited by Armand Bonner (edited May 16, 2000).]