Are BOV's bad for a Z32 TT??

[z32_Chase]

So ive heard from some Z32 guys and im wondering if what they say is true? So the FAQ is are BOV's Bad for the VG30DETT? And if installing a MAP sensor would help (because a MAF sensor would tell the ECU to dump more fuel into the engine) SO????

[t.mcginley.jr]

The general rule for any turbo engine is:

MAF - recirc valves

MAP - BOVs

Using BOVs with just a MAF sensor (like our cars) will shorten turbo/engine life

[nissanfreak12]

Using BOVs with just a MAF sensor (like our cars) will shorten turbo/engine life

I want the proof!!!!


Honestly, this is the first time i heard that. I have heard it makes the car die when it releases pressure. Then I also heard you can get the ECU program to account for the loss of metered air.

[Metacom]

The 2nd previous owner of my Z installed BOV's. MAF and stock ECU. No problems here...

[agent4573]

Theoretically, if you installed the BOV between the turbo and the MAF it should make all these concerns go away right?

[t.mcginley.jr]

The main reason that I've found is that when the BOV releases, it greatly decreases the amount of metered air (already measured by the MAF) that is going into the combustion chamber and messes up the A/F ratio. Basically whenever you hear the BOV release when you let off after boosting, the engine will run extra rich for a short period. Eventually this will wear out piston rings faster than they otherwise would (and any cats if you have them). Theoretically I guess you can reduce this effect with a good tune and EMS, but whatever lol

Not sure if this adversely effects the turbos or not

[Metacom]

Its seems to be a point of argument when it comes up, there is an informative thread couple years ago on TT.net about BOV vs recircs

http://twinturbo.net/nissan/300zx/forum ... circs.html

Pros n cons for both. BOV's wont hurt anything when installed correctly. Its all a matter of what works best for you.

...but that noise off BOVs is kinda addicting...

[z32_Chase]

so what im hearing is it would be safer to run a MAP sensor with BOV's? without any tuning?

[z32_Chase]

also i am not sure where to buy a MAP sensor for the Z is there some sort of a conversion involved? / kit?

[nissanfreak12]

also i am not sure where to buy a MAP sensor for the Z is there some sort of a conversion involved? / kit?

There is and it is PRICEY!!!! That is if you can even find one. Run it with the MAF and get the ECU tuned to compensate for the loss metered air. That is your easiest and cheapest solution.

[NolimitZ32]

In theory there is a way to run MAF with BOVs and not hurt anything. By installing the MAF in blow-though configuration and downstream of the BOV you will actually meter the exact amount of air going into the engine at any given time even with the BOVs open. However I have never seen this done on a Z successfully and it would most certainly require fine tuning.

[ThisIsSparTTa]

Greg @ SZ is pretty respected and pretty opinionated on the topic: http://www.nicoclub.com/archives/z32-30 ... alves.html

[NolimitZ32]

^ Don't really understand whether you are trying to refute what I said or not but if you are I can guarantee you that you have already lost the argument. What I said has been done on many a MAF car. Doing a blow-through setup is only hindered on the Z32 by the limitations of tuning the factory ECU. A MAF sensor in essence is a better system than the MAP because it measures the actual amount of air coming in where as the MAP sensor uses pressure to pull values from a table. As for what I said, it stands true, its a mechanical/physical FACT, and it is possible to make it work on any MAF system the only difference is the amount of money you have to throw at it. Finally, it is impossible to properly tune for the opening moment and loss of metered air in a pull-through system, you can get close but you'll never get it exact.