Regards Bov to Air
Apr 8, 2003, 04:21 PM
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Regards Bov to Air
I been driving the the evo with the greddy type S venting into air for a couple of weeks.. I finally got it adjusted so that my car was buidling back to full boost instead of the partial.. Anyways One thing i realized.. After a little of spirited driving and venting at 5k rpm.. if you put the car in neutral right after it vents in slower speed.. the rpm will drop below 500 and i had it go on me once.. never had it go on me during Higher speed( dude that would be scary) anyways Just dont' let it idle longer then necessary after you vent.. or don't blow off at higher rpm at lower speed, then put in neutral.. everythign should be fine!!
Apr 8, 2003, 04:42 PM
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I have noticed mine doing that without any modifications. It doesn't stall but if I push hard then stop at a light it will drop very low and idle very rough. If I rev it once it will settle back ot the regular idle speed.
Apr 8, 2003, 04:48 PM
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this is the irratic idle associated with open bovs. and what i was affraid of. i got the hks, but have yet to install. the greddy type s on my stealth tt open loop stalled too much, and had a terrible idle. so i set it back into the intake... it was still just as loud because of the intake, but the stall went away. i may have to sell the hks and go with a closed design. try putting an intake on your car, and then route it just like the factory bov was. it should drive fine, and you should be able to hear it pretty loud.
Apr 8, 2003, 04:48 PM
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i really dont understand this blow off vavle BS. does the stock valve open and vent air during idle? i hope and think that it wouldnt, and if it doesnt, y the hell would the car run like crap with an aftermarket blow off valve that also remains shut under idle.......
Apr 8, 2003, 04:59 PM
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Originally posted by ADMstunna
i really dont understand this blow off vavle BS. does the stock valve open and vent air during idle? i hope and think that it wouldnt, and if it doesnt, y the hell would the car run like crap with an aftermarket blow off valve that also remains shut under idle.......
i really dont understand this blow off vavle BS. does the stock valve open and vent air during idle? i hope and think that it wouldnt, and if it doesnt, y the hell would the car run like crap with an aftermarket blow off valve that also remains shut under idle.......
Apr 8, 2003, 05:18 PM
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I have no problem at all with my HKS blowoff valve, never got stalled after I rev high, 
Originally posted by rt turbo
when an open loop bov vents durring idle it is different than the factory because the factory vents into the air intake. the open loop is venting out into air so the measured air is gone, and hence... not measured. when an aftermarket bov doesnt not vent durring idle the car should IN THEORY idle better. this is my hopes with the HKS, because it remains closed always until venting pressure is required. the greddy type s is designed to vent durring idle because it is designed to be recirculated, and act as a factory replacement, only better, with better sound. that is why the greddy s will cause the irratic idle and maybe even stalling. the blitz ssbov wont make a car stal, but it will give a bad idle. it closes imediatly after venting, but opens once car is at idle, which stops stalling, but still gives irratic idle. so, i hope the hks will work.
when an open loop bov vents durring idle it is different than the factory because the factory vents into the air intake. the open loop is venting out into air so the measured air is gone, and hence... not measured. when an aftermarket bov doesnt not vent durring idle the car should IN THEORY idle better. this is my hopes with the HKS, because it remains closed always until venting pressure is required. the greddy type s is designed to vent durring idle because it is designed to be recirculated, and act as a factory replacement, only better, with better sound. that is why the greddy s will cause the irratic idle and maybe even stalling. the blitz ssbov wont make a car stal, but it will give a bad idle. it closes imediatly after venting, but opens once car is at idle, which stops stalling, but still gives irratic idle. so, i hope the hks will work.
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Apr 8, 2003, 05:24 PM
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Originally posted by wing240
I have no problem at all with my HKS blowoff valve, never got stalled after I rev high,
I have no problem at all with my HKS blowoff valve, never got stalled after I rev high,
Apr 8, 2003, 06:31 PM
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at idle is'nt the car under vacuum? if so how the hell is and why the hell is air escaping/ venting?
damn this blow off valve bs is gettin me all agitated and i dont even have one.
damn this blow off valve bs is gettin me all agitated and i dont even have one.
Apr 8, 2003, 06:59 PM
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Originally posted by rt turbo
when an open loop bov vents durring idle it is different than the factory because the factory vents into the air intake. the open loop is venting out into air so the measured air is gone, and hence... not measured. when an aftermarket bov doesnt not vent durring idle the car should IN THEORY idle better. this is my hopes with the HKS, because it remains closed always until venting pressure is required. the greddy type s is designed to vent durring idle because it is designed to be recirculated, and act as a factory replacement, only better, with better sound. that is why the greddy s will cause the irratic idle and maybe even stalling. the blitz ssbov wont make a car stal, but it will give a bad idle. it closes imediatly after venting, but opens once car is at idle, which stops stalling, but still gives irratic idle. so, i hope the hks will work.
when an open loop bov vents durring idle it is different than the factory because the factory vents into the air intake. the open loop is venting out into air so the measured air is gone, and hence... not measured. when an aftermarket bov doesnt not vent durring idle the car should IN THEORY idle better. this is my hopes with the HKS, because it remains closed always until venting pressure is required. the greddy type s is designed to vent durring idle because it is designed to be recirculated, and act as a factory replacement, only better, with better sound. that is why the greddy s will cause the irratic idle and maybe even stalling. the blitz ssbov wont make a car stal, but it will give a bad idle. it closes imediatly after venting, but opens once car is at idle, which stops stalling, but still gives irratic idle. so, i hope the hks will work.
Blow off valves that vent to atmosphere are fine when a car uses a MAP (Manifold Air Pressure, also known some times as speed/density) system for fuel management. A MAP system measures the pressure inside the intake, after the throttle body, and then adds fuel based on this amount of air. The air is not measured until it actually makes it into the intake
Recirulating Blow off valves (really a compressor bypass valve since they don't vent) direct the air back into the intake track before the turbo. They are used on systems that use MAF (Mass Air Flow - AKA hot wire) systems. The MAF system Mesaures the air coming into the engine at the near the beginning of the intake tract. Think about a turbo system and you have several feet worth of intake plumming. These cubic feet of air have been measured, and fuel has been added to match that amount of air.
When you add a blow-off valve that vents to atmosphere on a system that uses a MAF it causes problems with the Air/Fuel mixture, every time it is venting. This is why cars will stumble/stutter/stall during gear changes. The reason is the air that is being vented has already been measured and had fuel added for that mass of air. The blow off valve just vented all that pressure outside the intake tract. Your A/F ratio is now something like 7:1 or worse. So the car bogs from the way over-rich A/F ratio.