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read a post not to long ago about having the car stuble as the BOV opens due to the fact that the AFM is slamming shut. does thi happen on all stock EFI turbo datsun cars with the AFM an a aftermarket BOV?......wold i be better off just buying a 1G eclipse BOV and have it route back into the intake after the AFM?
i really want that sound...an would love the have a turbo XS type-h RFL but if im going to have problems then i wont waste the money

thanks!

-Sparky
72 240ZT
 

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if the BOV is venting into the air then the car is going to go rich suddenly. because the air has been metered and the ECU adds the necessary fuel but the BOV removes the air so the car goes rich. venting the BOV upstream of the AFM will cure this.

ALSO i have noticed there seems to be some confusion between the emergency pop-off valve and the blow off valve. to clarify just in case people are using the wrong terms the POP-OFF VALVE or EMERGENCY POP OFF VALVE, is the valve on your manifold that is spring loaded to vent gasses into the atmosphere in case of an overboost condition. if you increase the boost in your car\ you either need to remove and plug the hole or shim the spring with washers so the valve will open at a higher boost level.

the BLOW OFF VALVE. is the valve the re-routes the air in between the turbo and throttle body either into the atmosphere or back into the intake stream when the throttle is suddenly slammed @!#$ i.e. shifting and there is still pressurized air from the turbo that is trapped between the throttle body and the turbo. if the gasses were not vented it would travel back to the turbo causing alot of turbulance and stalling out the turbo. the 280zx does not come from the factory with the blow off valve. however it is a nice mod to have as it prevents turbo wear and allows the turbo to spool back up quicker in between shifts.
 

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I have a BOV venting to the atomosphere and yeah it does cause a rich situation when it does. But I heard about HKS having a device that is supposed to buffer the AFM readings during this time. I think it's called an EIDS. It comes on the Super AFR that they are selling now. The purpose of the EIDS is to reduce the rich situation from the BOV venting. That device should be able to allow you to have a BOV making the nice sounds while not ruining the driveability of your car.
John
 

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Just a trick. i used to just pull the thing open and let it snap shut a few times every once in a while. it seemed to help response at lower rpms. i also got down to the vacuum mechanism once and moved that around by hand and it seemed to help a little. it had been sitting a while and i figured it might be getting stuck open so i lose boost. you might just try that.
 

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i just put on a greddy type S bov today, its venting into the atmosphere, and i dont have any engine stall problems, i have an 83 turbo, and if i set the BOV to a softer setting, it will idle a little harsher, as if it has a vacuum leak, but once i tighten it back up towards the harder setting, it idles fine with no problems, when it vents to air, it has no problem keeping the engine running fine, if its going rich i can't tell, i may put an a/f ratio gauge on it, but as of right now, im having no problems
 
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