Quote:
Originally Posted by biasword
fwiw i have blacktop with maf with a ssqv vented to atmosphere and have no issues. between shifts or otherwise
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1. SSQV does not hang open at idle nor does it release much if any airflow at low pressure, say 0 to 5psi. Instead, it forces compressor into surge condition which will wear out the turbocharger.
2. The OEM and PFC ecu have a fuel cut for TPS conditional < 1.5%? above roughly 1400rpm which means while the bypass is open there is no issue with overfueling the engine in my experience even with a maf sensor.
The issue with overfueling occurs on push-type bypass (like factory style) where it can hang open under 1400rpm preventing surge, the maf tries to idle the engine and the leaking air causes excess fuel and idle issues.
Correct solution is push style bypass recirculated, prevent surge, prevent over fuel condition. SSQV is a trade off, you give up turbocharger lifespan for the atmospheric blow off affect. Indeed we installed hundreds of SSQV back in the day because we knew it would keep the engine running smooth despite being atmospherically vented. However you can easily hear the surge conditional and now understand it means excess compressor wear.