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Discussion Starter #1
is anyone elses bov doing this? while on cruise control or just cruising at the same pedal pressure on autobahns the bov opens and closes repeatedly. its annoying as hell. is there a way to get this damn thing to just stay closed like its supposed to until the pedal is released?
 

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Is it a rapid noise? If so that isn't the bov it's your throttle body your hearing. If it isn't Rapid remember these turbos spool really quick. If your contently in and out of boost it will contently vent. You don't have to fully release the throttle to get out of boost. Just back off enough to were the car goes into vacuum. Alot of people will blame the solenoid. It's just the nature of a small, fast spooling turbo.

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Discussion Starter #4
i had a turbosmart 50/50 and now a boomba. it has done this with both. its not rapid. its very annoying. none of my other boosted cars ever did this. had a 1g dsm and my evo ix with both the stock turbo and the gtx3582 dint do this. this is the first time im encountering it.
 

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Turbosmart 50/50 sometimes mine will vent when I am sure I am not letting off the throttle. Sounds like a long drawn out "ttttttttttttttssssssssssssshhhht" about 2-4 seconds. Is that the same as you are hearing?

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Yes, you need to have your tuner tune the BOV tables or run manifold pressure directly to the valve and tune the hardware yourself.
Joe can you elaborate?

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Joe can you elaborate?

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Sure, there are parameters in the calibration which then commands the BPV to open or close. Simply, while the BPV is actuated based on vacuum or boost, there is as solenoid that controls the operation. On a traditional BPV, a reference line is run from after the throttle body which feeds the valve manifold vacuum and boost. You tune the spring based on manifold vacuum and done.

On the ST, there are two possible references. The vacuum pump which is constant vacuum, and the compressor outlet which almost always in positive pressure if off-idle or decel (and higher pressure than the manifold ever will be). The solenoid then switches between providing the valve vacuum which will always open it, or boost from the compressor outlet which will always keep it closed. Once you change the valve design and spring tension, the stock table which commands the solenoid to switch sources isn't calibrated correctly anymore. This can cause surge, the valve to cycle on and off, constant venting, etc.

If you run a manifold reference, most aftermarket valves can have springs swapped or tension adjusted to tune it to manifold vacuum. If you keep the OEM solenoid control, you're doing the same thing, but with the calibration tables.
 

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Discussion Starter #10
so basically i could get me one of those sound symposer block off plates with a vacuum port and run the line directly to the bov couldnt i? because this **** is next level annoying
 

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so basically i could get me one of those sound symposer block off plates with a vacuum port and run the line directly to the bov couldnt i? because this **** is next level annoying
Yes. And don't forget to cap off the vacuum line solenoid when you do this.
 

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so basically i could get me one of those sound symposer block off plates with a vacuum port and run the line directly to the bov couldnt i? because this **** is next level annoying
I wouldn't. The valve that is in your turbo has a spring that works with the factory solenoid. If you attach it directly to your symposer delete the valve will be open at idle. Now if your running a TiAL, Hks or other bov attached to a charge pipe you can by making sure you have the correct spring installed.

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I wouldn't. The valve that is in your turbo has a spring that works with the factory solenoid. If you attach it directly to your symposer delete the valve will be open at idle. Now if your running a TiAL, Hks or other bov attached to a charge pipe you can by making sure you have the correct spring installed.

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That shouldn't be a problem (open at idle). Most other cars are this way. Even if it were a MAF car, that's all metered air.
 

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Discussion Starter #16
its supposed to be closed at idle, thats what the spring is for to match the idle mecury inches or whatever the hell its called while the engine is idling to keep it shut
 

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99% sure it would be open. The BPV is very similar to a single piston BOV. In order to run a BOV on a MAF car, you need a dual piston which stays closed at idle. There is a second piston which is not affected by manifold vacuum and stays closed.

A BPV (not electronically controlled) and single piston BOV would both be open at idle if adjusted properly. If the spring was stiff enough to stay closed at idle vacuum, you would get a lot of surge when lifting throttle out of boost, but where the turbo is beginning to spool.

Just one example:

http://www.turbosmart.com.au/technical-articles/can-a-bov-damage-my-engine/
Standard BOV’s are designed to be open at low vacuum levels which aid in reducing emissions. Most standard cars idle between 18 – 21 inHg. This means that when the engine is between full vacuum and 5 inHg, the valve is open, not allowing the turbocharger to pressurize the intercooler and piping. When the valve closes, the turbocharger needs to pressurize the intercooler and intercooler piping, before the intake manifold is pressurized resulting in a delay in boost pressure.

Due to the spring force required to keep the BOV closed at idle, the response of the BOV is reduced at low throttle openings which may result in light cavitation from the turbo charger at low RPM (Joe - This refers to the TurboSmart valve, not OEM). This level of cavitation is negligible as the turbo speed is relatively low which means the resulting stresses on the bearings are low.
 

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99% sure it would be open. The BPV is very similar to a single piston BOV. In order to run a BOV on a MAF car, you need a dual piston which stays closed at idle. There is a second piston which is not affected by manifold vacuum and stays closed.

A BPV (not electronically controlled) and single piston BOV would both be open at idle if adjusted properly. If the spring was stiff enough to stay closed at idle vacuum, you would get a lot of surge when lifting throttle out of boost, but where the turbo is beginning to spool.

Just one example:

http://www.turbosmart.com.au/technical-articles/can-a-bov-damage-my-engine/
With the correct spring for our cars and running off the intake manifold the TiAL valve stays closed. This is not a dual piston design like you stated and no sign of compressor surge.

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With the correct spring for our cars and running off the intake manifold the TiAL valve stays closed. This is not a dual piston design like you stated and no sign of compressor surge.

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I would say that spring is too stiff then. Does it release cleanly when lifting in vacuum?
 

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I would say that spring is too stiff then. Does it release cleanly when lifting in vacuum?
Are you asking myself or the OP?

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