Greddy + BOV's = stalling?
 

Anyone ever hear of BOV (mounted before MAF) causing car to sporadically stall? Any input on reason & solution would be great. Thx in advance guys.

Super AFC II will fix that problem.

Re: Greddy + BOV's = stalling?
 

Let me elaborate the question.

1. Would a BOV mounted after the MAF before the throttle body cause engine stall after severe engine braking on the Greddy TT kit set up.
( It does on our first TT kit and still doing it. It doesn't do it all the times but enough to be annoying. Right Jordan?)
Possible solution.... tighting up the BOV valve so it let out less air....possible....

2. Would a BOV mounted before the MAF but after the turbo cause engine stalling problem or any other ill effects on the MAF long term wise on the Greddy TT kit set up.
( never tried it but have been told the MAF might be damaged long term wise...maybe it's a myth but no one with a Z has the turbo kit long enough to confirm anything.)
This is probably the best solution if you want a BOV integrated in your TT setup.

I also like to know how can SAFC2 fix the problem since I have never used that unit before. ( sorry, SAFC1 is the last kind of piggyback unit I have used, everything else is standalone. Not familiar with the new functions.)

another member just got his Greddy kit installed. His post is a couple threads down. Something like t32zz or such.

Anyway, they had to remove the Tial wastgate because it was venting too much Air during shifts, and even during idle.

They switched to the greddy BOV, which allowed them to adjust to correct the problem.

Jotech did his install. I think his thread has about 70 or so responses.

thanks

These two quotes are from the 450HP Jotech Greddy kit thread.

It's not that they changed out the Tial wastegate but they first used a Tial BOV and found it to be not adjustable and leaked air so they later changed to Greddy unit so it can be adjustable. They mounted their BOV after the MAF Before the throttle body. They also tighten up the Greddy BOV adjusting valve IMO to avoid stalling.

Dollar99 - I don't think SAFC2 can fix the stalling problem caused by the BOV. I think you read wrong in that same thread unless it really have a anti-BOV stalling function or some kind of trick to fool the MAF just for the BOV venting.

you need something like the "decel air" feature of the super afc2.
this basically lies to the ECU and says a lot less air is coming in when you let off, so the engine does not stall on too much fuel.

i have this and so does tim (t32gzz).

stalling problem will exist no matter where the BOV is, if it is blowing off to atmosphere.

Thx for chimming in, do you have pix of where you mounted yours?

LOL, mystery solved. Thank you.

mounted my super-afc2 , or bov?

here is where my MAF is:
https://my350z.com/albums/albur86/abw.sized.jpg

here is where my BOV is:
https://my350z.com/albums/albur86/aca.sized.jpg

michael

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If you think about....unless you are using an APexi AFC-II to enable the use of the "decel air" function the placement of the MAF before the BOV would not work well. As the BOV vents to the outside the MAF would still see air movement past it and would register airflow to the ecu giving a rich stall problem. If you go the other way an install the BOV before the MAF then when the throttle plate shuts the intake air movement past the MAF would stop and you would not get a reading for the ecu to add fuel. The pre-MAF placement of the BOV would be the better solution if you were not using the Apexi unit.

the bov after the maf is perfectly fine. the bov vents when you shut the throttle. if the throttle is shut the computer is not adding fuel anyway, so it doesn't matter what the maf is reading. the closer to the tb the bov is mounted, the more responsive it is.

I don't know if this is necessarily true for the 350Z. It would seem that the Apexi "decel air" function may be required to make this work with the MAF before the BOV. At the least I think the computer would throw a code because it would be getting a larger airflow reading from the MAF even with a closed throttle position. I bet these 2 conflicting inputs would make the ecu freak.

What about the negative effects (if any) on the MAF if the BOV was mounted before the MAF?

I think the effects would be minimal because boost would be vented before the MAF...the MAF would not see the boosted charge once the throttle closed. If you kept the MAF in the stock location and put the BOV in the driver front corner ( only are with any room) I think that would be the closest set up to factory that you could get realistically while boosting an N/A car.

g356, so with your suggestion, that would be placing the BOV before or after the MAF? Sorry for the stupid question.

If the BOV is placed prior to the MAF, and it does not vent fast enough to cause air to reverse direction through the MAF, it would not be possible for the BOV to mess with your air/fuel. The MAF would still read exactly how much air mass your engine is consuming.

Even if depressurization causes air to reverse through the MAF, it will still give a more accurate reading with BOV pre MAF than post MAF. There is a certain amount of air pressure in the throttle and plenum that has to go somewhere. I'm guessing most is consumed by the engine, and a little bit if any will go back through the MAF and out the BOV. That will give a far better reading than evacuating the entire volume of the intercooler and the majority of the piping through the MAF.

It's not a stupid question at all.With the Greddy kit the BOV will go down in the driver front corner before the MAF on my car. There are a few of us who are adding the BOV because it does not come with one in the kit from Greddy. I think it is a must for any kit.....apparently Greddy thinks they do not need it. Possibly for emissions reasons.:)

like deviousZ did ?

Did he experience any problems?