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I have a HKS SSQV atm dump valve and power fc in my rb25det, I'm having problems with the engine stalling when I rev it then push the clutch and let go of the throttle. It often happens in stoplight crossing etc and is really annoying.

Is there any settings in PowerFC I can adjust to make it stable when falling down towards idle? I've tried rising the idle rev up to 1k rpm but it does not help.

Is the only fix to resirk the dumped air back after the maf? I've heard you can tighten the ssqv spring?

So this is something a dyno tuner can fix when they map the powerfc?

what do you mean "get a real bov", it is a genuine HKS SSQV, not a ebay fake. I also bought the resirk kit but have not installed it since because it will be about 1.5meter with 35mm air hose to resirkulate the air back to the inlet after the maf.

#1

map tracer

repeat the stall

then tune those areas it runs across when it stalls

or

#2

get a real bov

#2 is easier

There is a quick, free fix. Put the stock BOV back on.

Thats what Paul means by a real BOV, one thats actually designed for a purpose :D

A tuner can tune out the stalling if they know what they are doing.

2 seconds with the datalogit and i gaurantee no stalling no matter what bov. It is all a matter of catching the idle.... bit of timing tweaking and fuel fiddling and all will be sweet.

Yep reall BOV well one that recirculates or "plumbs back" into the intake after the afm and before the compressor, problem solved, although it can be tuned out aswell but as mentioned recirc is easier

The original GTS25t bov is rumored to leak above 1bar boost, so I bought the HKS ssqv. I have the resirkulation kit but I kinda fell in love with the atm dump sound :D I just got the engine up and running after a complete rebuild so im taking it to a dyno tuner shop next week. I only now how to set up the basic settings in powerfc to make sure it runs on safe AFR values and not leans out.

So then it is settled, I'll let the tuners program powerfc with a laptop and the stalling problem will be solved!

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