# BOV on 80's Z?



## preluder3084 (Mar 29, 2004)

ive been looking around and i know there are turbo Z's but i havnt seen many people with BOV's. IS there a reason for this or something. just looking for some info.


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## 0341TODD (Nov 15, 2003)

you dont really need one man since the car doesnt boost over 7.5 psi with the pop off valve. but once you take the pop off valve off the plenum and start boosting higher you need to get one- I have an apex integration one that I need to get a flange welded for, but Im deciding where and how to run my intercooler.


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## 0341TODD (Nov 15, 2003)

let me rephrase that- you dont really need a blow off at 5 psi or below- sorry from what I know .......obviously a bov is good to have in any case since you wont have any kind of compressor surge as long as it is adjusted right.


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## preluder3084 (Mar 29, 2004)

hehe, but i do like the noise it makes, i know it sounds ricy but i do like it, and since you were talkign about the intercooler where the hell is the stock one or is there one?would it hurt the car putting a BOV on it anyways if only boosting at 7 PSI


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## 0341TODD (Nov 15, 2003)

no there is not a stock one and no it wouldnt hurt if you put a bov on at 7 psi- but you want to plug the pop off valve opening.


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## 87_300zxT (Nov 18, 2003)

It would be better to just buy an adjustable pop-off valve form jim wolf, that would minimize boost loss, or a non atmospheric valve(not sure on that) a compressor bypass valve I believe, I have heard of people modding the bypass valve from stock turbo dsm's and slapping them on their older z. They are from what I here excellent, but so sa far with the good ol twin chamber blow off valve you gotta watch for boost leak, cause on a car like the older z any lost in boost pressure would be detrimental on your hp numbers(the max on the stock turbo is like 15-16psi, appropiately modded, over that it will spike) so you see there is not a huge range to work in and a loss of pressure would not be efficient

But im definately going to take precautions against compressor surge, I hear the HKS tc bov is great and dosn't leak


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## morepower2 (Apr 19, 2002)

preluder3084 said:


> ive been looking around and i know there are turbo Z's but i havnt seen many people with BOV's. IS there a reason for this or something. just looking for some info.


It is needed if you you run 10 psi or more of boost. It has to be recirculated behind the MAF as well, not just dumped to the atmosphere.

Mike


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## Zen31ZR (Mar 24, 2004)

morepower2 said:


> It is needed if you you run 10 psi or more of boost. It has to be recirculated behind the MAF as well, not just dumped to the atmosphere.
> 
> Mike


Unless you move the MAF to a post turbo location. There's a few tuners that have done that on various cars here. It's only real benefit IS to be able to dump the BOV to atmosphere without running rich , there is no other benefit otherwise.


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## morepower2 (Apr 19, 2002)

[email protected] said:


> Unless you move the MAF to a post turbo location. There's a few tuners that have done that on various cars here. It's only real benefit IS to be able to dump the BOV to atmosphere without running rich , there is no other benefit otherwise.


Have you had sucess with this? I would think that the turbo might cause wierd metering problems on overrun. Stillen tried that on their maxima supercharger kits and it didnt work.

Mike


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## Zen31ZR (Mar 24, 2004)

morepower2 said:


> Have you had sucess with this? I would think that the turbo might cause wierd metering problems on overrun. Stillen tried that on their maxima supercharger kits and it didnt work.
> 
> Mike


No , I'm not that far along in the Zs mods process yet. But I was considering it. I did it on my DSM and it worked ok.


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## morepower2 (Apr 19, 2002)

[email protected] said:


> No , I'm not that far along in the Zs mods process yet. But I was considering it. I did it on my DSM and it worked ok.


I was wondering because MAF's are pretty senstive and if you close the throttle, the turbo is still spinning and packing air in, the BOV opens but you got a lot of volume there. Cars that I have seen try this sometimes stall from too rich then. I never have tried it myself though.

Mike


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## Zen31ZR (Mar 24, 2004)

morepower2 said:


> I was wondering because MAF's are pretty senstive and if you close the throttle, the turbo is still spinning and packing air in, the BOV opens but you got a lot of volume there. Cars that I have seen try this sometimes stall from too rich then. I never have tried it myself though.
> 
> Mike


It doesn't work bad if you can put the BOV just in front of the MAF , rather than further back. Prevents the turbo from packing air into the MAF as you say , since the pressures all being jettisoned right at that point. My BOV on the DSM was only an inch or so away from the MAF. I know some of the guys who had it farther away , in the stock location , and the MAF right up by the TB had that problem. Still have the air thats past the BOV rushing into the MAF , even when the BOV opens.
Overall , it's still best to recirculate , especially on a street car with a normal ECU. I suspect with the AEMs and the Haltechs and etc , the over-rich effect can be tuned out.


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