forge bpv recommendations?

[patty AT forge]

That would be flutter. Engine vacuum alone is enough to open the valve with the red spring so ****in theory**** it is fine for any set-up and boost levels on these cars.

In practice it is a bit more complicated. Ideally you do not want flutter but if tuning out the flutter leads you to use a spring that is too soft then the trade off is slower boost response and potentially lower boost levels.

Think about that for a second... what is causing the increased spool time and the boost to lower? Its a leak. Now turbochargers are feedback systems. Diverter valves and blow off valves ARE NOT boost control systems. If spring tension is causing your boost to lower than the boost control mechanisms (wastegate, solenoid, etc) are still trying to regulate boost to that higher level. This means that your shaft speeds are drastically increased to make the same boost level or in extreme cases LESS boost. This is terrible for turbo longevity and once the turbo ends up operating outside of its efficiency range it can have a detrimental effect on engine life also.

The flutter you are hearing is caused by a pressure differential of a few psi and isn't really something to be concerned with. That being said if you notice no performance difference with the blue spring and shims go with that arrangement. If there is no difference go with the softer set-up.

 

[zaka]

Thanks Patty

I could feel the difference between red and blue (1 or 2 shims). Red holds really better and built boost is stronger but a little bit slowly than the blue one.
I think I will take the safe mode -> blue+2. less flutter than the red one.
Blue+1: No flutter, but don't hold boost

 

[ericrapp]

I have played around with this for awhile. I am running blue and two. Flutter is what you might hear. as i do. Thats ok.

 

[Willieville]

how did you guys get the forge open, I tried my hardest to open it, but it wouldn't open. I bought mine from another member (not here) and all I got was the yellow and red spring, the yellow is def not holding the boost I want so I want to switch it out for the red.

 

[08cosmic3]

how did you guys get the forge open, I tried my hardest to open it, but it wouldn't open. I bought mine from another member (not here) and all I got was the yellow and red spring, the yellow is def not holding the boost I want so I want to switch it out for the red.

I use a large set of channel lock pliers and a peice of leather so not to scratch the BPV. I run Blue spring w/2 shims. Where is the blue spring? Do you have the shims? Try yellow with two shims. You will need the blue spring IMO. The red is mostly for those running high boost. Call Forge and order the blue spring form them, should be cheap.

 

[Willieville]

not sure where the blue spring is, I think I might try the red for a bit without any shims first and if I don't like it I'll contact forge. now to get into the damn thing!!! atleast it sounds great.

 

[ericrapp]

Hey there, Willieville. I also push down on the cap when i loosen or tighten. Please remember to keep the internals clean when playing with it. I would suggest the yellow spring with a shim or two first till you contact Patty@Forge. you can pm and you will get excellent service and advice too. 08cosmic3 is giving good advice here. The outer ring will unscrew from the body removing the cap or hat, exposing the spring and shims.