forge bov

[Tagkat]

I'm a noob what does surge feel like I have the blue spring in mine and don't have any problems, I think.

 

[nypest]

It seems to me thats it only issue as EVERYone says that the blue spring works for them

 

[SicSpeed]

Its almost like the BPV with the blue spring doesent dump all the boost when you let off in patrial throttle low boost situations. Like a quick pass on the highway maybe like 5PSI if i take my foot off the gas at all either the valve doesent relese the pressure at all or just not all of it so it surges back to the turbo. I thought it was because the blue spring might have had to high a rate and when i looked it up the blue spring was rated for 23+ PSI. So naturally i went to the yellow and it stopped but it held boost better with the blue, so i added a shim and that seemed to work the best for me. It seems to me thats it only my issue as EVERYone says that the blue spring works for them.... no idea?

Heres some info

Valve Fluttering:

Valve fluttering is commonly thought to be an automatic indicator of compressor surging, and I would like to put that rumor to rest right now. This could not be further from the truth.

Compressor surging (caused by a bypass valve) implies that the bypass valve is not opening fully to allow the optimal amount of airflow required to keep the compressor wheel of the turbo spinning at an optimal speed.

Bypass valve fluttering will occur under various circumstances, so please consider under what situations you are experiencing fluttering before you presume that compressor surging is taking place, or more importantly, before it is assumed that a problem even exists.

Valve fluttering under wide open throttle or full boost throttle lift, again, typically means that a valve is tuned or adjusted to stiffly, and while this can lead to compressor surging and potential damage over an extended period of time, if the user fixes the issue quickly, no significant damage will occur. It would only be after prolonged use of a valve in an improperly tuned configuration that compressor surging MAY lead to damage or excessive wear on the turbocharger.

Valve fluttering under partial throttle or partial boost throttle lift, on the other hand, is a completely normal occurrence and IS NOT an indication of compressor surging by any measure.

Partial throttle or partial boost valve fluttering is solely an indication that the valve is directly responding to the inconsistent pressure differential on either side of the throttle plate (throttle body).

An internal combustion engine naturally creates a vacuum effect during the intake stroke of a given cylinder. When boost pressure is built from the turbocharger, it will reach a certain level inside the intercooler piping, but as it enters the intake manifold, it is almost instantly reduced by a given amount of vacuum created by the intake stroke of the engine, thus resulting in a marginally lesser amount of boost pressure inside the intake manifold compared to inside the intercooler piping.

Since the bypass valve sees references from both of these pressure sources, the sealing surface of the valve, be it a diaphragm or a piston, will respond to these differences in pressure, as minor or severe as they may be. This sealing surface response is what is creating the fluttering effect at partial throttle or partial boost throttle lift.


Im using blue myself.

 

[nypest]

Heres some info

Valve Fluttering:

Valve fluttering is commonly thought to be an automatic indicator of compressor surging, and I would like to put that rumor to rest right now. This could not be further from the truth.

Compressor surging (caused by a bypass valve) implies that the bypass valve is not opening fully to allow the optimal amount of airflow required to keep the compressor wheel of the turbo spinning at an optimal speed.

Bypass valve fluttering will occur under various circumstances, so please consider under what situations you are experiencing fluttering before you presume that compressor surging is taking place, or more importantly, before it is assumed that a problem even exists.

Valve fluttering under wide open throttle or full boost throttle lift, again, typically means that a valve is tuned or adjusted to stiffly, and while this can lead to compressor surging and potential damage over an extended period of time, if the user fixes the issue quickly, no significant damage will occur. It would only be after prolonged use of a valve in an improperly tuned configuration that compressor surging MAY lead to damage or excessive wear on the turbocharger.

Valve fluttering under partial throttle or partial boost throttle lift, on the other hand, is a completely normal occurrence and IS NOT an indication of compressor surging by any measure.

Partial throttle or partial boost valve fluttering is solely an indication that the valve is directly responding to the inconsistent pressure differential on either side of the throttle plate (throttle body).

An internal combustion engine naturally creates a vacuum effect during the intake stroke of a given cylinder. When boost pressure is built from the turbocharger, it will reach a certain level inside the intercooler piping, but as it enters the intake manifold, it is almost instantly reduced by a given amount of vacuum created by the intake stroke of the engine, thus resulting in a marginally lesser amount of boost pressure inside the intake manifold compared to inside the intercooler piping.

Since the bypass valve sees references from both of these pressure sources, the sealing surface of the valve, be it a diaphragm or a piston, will respond to these differences in pressure, as minor or severe as they may be. This sealing surface response is what is creating the fluttering effect at partial throttle or partial boost throttle lift.


Im using blue myself.

Thanks good stuff here so if i am getting a "flutter" i would be right in saying that the spring rate on the blue spring is to great! However im not going off of sound, im going off of feel. When i let off the throttle the car gripes foward. Using the yellow spring its all smooth and using the blue its all harsh....Maybe its not surge or flutter maybe its a normal reaction to the throttle fully closing while still making some boost(my driving style pehaps in this situtaion?) It just seems like unless im making greater than 10psi the BPV is not reacting proper(using the blue spring) Again im sure this is just me as the blue spring is the one everyone likes.

 

[tru-boost]

the best way to "tune" a bov is to go as stiff as possible without comp. surge. i have never at any boost level gotten surge with the blue spring, even with 2 shims. like mentioned above the flutter at low boost means you are set well. no matter what spring you use the forge valve will always open under vac. that is how it is designed. even with the red spring the valve is wide open at idle. the stiffer springs just make it hold boost better, and the release will require the engine to build slightly more vac. before it vents. i do get some surge with the red spring under low boost conditions, so i may go back to blue+2 shims....it sounds better IMO anyways.
the idea is for the valve to NOT vent all the air too quickly. that is where the performance gain comes in. if the spring is too loose, your spool up will be very long between shifts because it has to build all that boost all over again. a tight spring will only vent SOME air on a well executed shift. that means you will be back up to peak boost in the next gear much faster.

 

[nypest]

finally thank you !

 

[Ryz]

I like how everybody was giving me tons of crap for saying red spring before.

 

[ericrapp]

Not for the hybrid at all, it uses a conical spring and tension is adjusted by a ratcheting knob. The fact that the spring we use for the VAGs isn't stiff enough at the highest tension to get the spring to seal at idle on the 2.3 made me think to look into spring tensions on the MAZ3 valve.

Are you saying you would get surge while accelerating under those conditions or when lifting the throttle from one of them?

off topic, but it sure is cool a vendor/manufacturer gets involved with customer issues on the forum. bravo

 

[channah]

ya seriously thats dedication to the customer

 

[Haltech]

the best way to "tune" a bov is to go as stiff as possible without comp. surge. i have never at any boost level gotten surge with the blue spring, even with 2 shims. like mentioned above the flutter at low boost means you are set well. no matter what spring you use the forge valve will always open under vac. that is how it is designed. even with the red spring the valve is wide open at idle. the stiffer springs just make it hold boost better, and the release will require the engine to build slightly more vac. before it vents. i do get some surge with the red spring under low boost conditions, so i may go back to blue+2 shims....it sounds better IMO anyways.
the idea is for the valve to NOT vent all the air too quickly. that is where the performance gain comes in. if the spring is too loose, your spool up will be very long between shifts because it has to build all that boost all over again. a tight spring will only vent SOME air on a well executed shift. that means you will be back up to peak boost in the next gear much faster.

Hey Tru, do the shims go in first, than the spring, than tighten down the top?

 

[Haltech]

I like how everybody was giving me tons of crap for saying red spring before.

If you arent experiencing surge, dont worry about it. EVERY car is different!

 

[patty AT forge]

Hey Tru, do the shims go in first, than the spring, than tighten down the top?

Correct. Shims under the spring.

 

[Haltech]

Thanks Patty

 

[boosted3]

I knew I've heard the sound of the FBPV before, but I couldn't quite put my finger on it. It sounds like one of those Piccolo Pete/screaming fireworks things fizzing out.

http://www.youtube.com/watch?v=isPLMeTXKwM

right when it lights up is exactly what mine sounds like. heh(screwy)

 

[bbychvz]

LOL that thing sounds funny.......I'll still get one.

 

[driver311]

I like how everybody was giving me tons of crap for saying red spring before.

I run only the redspring and it blows off fine. i will run the red and shims at the track. the car holds boost way better with the redspring. On the dyno the car actually showed the differences with each spring. I s*** you not. I dynoed them all. God i have to much time

 

[numbnuts22715]

I run only the redspring and it blows off fine. i will run the red and shims at the track. the car holds boost way better with the redspring. On the dyno the car actually showed the differences with each spring. I s*** you not. I dynoed them all. God i have to much time

dunno if you posted these already, but i did a quick search and couldnt find it. Did you get your new dyno numbers?

 

[patty AT forge]

I'd like to see them too.

 

[Andrade08]

I run the blue spring with both shims. I have stock boost but I liked how it made the car feal at WOT when I shifted. Seemed to not drop off so much boost when I shifted fast. I get zero issues with this set up. I may be the first to say this but...........MAKE SURE your stock vacuum hose is tight on the nipple fitting. Mine wasn't while I was installing it. It is just some thing I have come to check after having vacuum leak headaches and issues on my last HotRod. I cut a little bit of the hose off and then put it back on with a little SS worm gear hose clamp. Sucker is tight now. This hose leaking could give you some low boost/vacuum malfunction?? Maybe??? I just knew I didn't like the way it was so I fixed it.

 

[kneedragger241]

Yikes, that is a pretty annoying sound.