no no, not at all...Thank you for all your info

 

anytime...just shoot me a PM...

 

First this is just my opinion and I do not claim to be a turbo expert. I'm just an engineer who needed to know how this BPV thing worked. I was just intrigued by so many contradictive explaination.

Yes, Agree if you are losing boost on acceleration your valve is bad. After reading all weekend on BPV operation I finally found the best info on this topic. The search was for "Vacume transfer valve". The operation of this value is controller by the size of the air chambers on each side of the diaphram. One air chamber is smaller than the other. So under acceleration the smaller chamber on top of the value pressurization changes faster (needs less air) this pushes the valve closed. So no matter how much boost pressure you are running a BPV should not leak. If your valve opens at steady state (constant boost pressure) your spring is too light. How can you tell this is happening I don't know? Is should be closed at idle.

So changing this spring and increasing the tension will make the valve open later during deceleration and it will stay open shorter as a greater differential is required to keep it open. From a manual transmission point of view this seems like a good Idea - helps your shift points. But for an auto I don't know. It's definatly a personal setting you'll have to try. I wish someone made a set of spring with different tensions. This way you could adjust for your driving style.

 

Got mine today and put it on, not fun unless you have real small hands, took it out for a drive didn`t seem any different to me, but then again $12 bucks, what should I expect

 

did you install it right? not saying your not mechanically inclinded but It works...

 

don`t know how you could install it wrong, just didn`t notice any difference, have gm stage 1 kit already installed, fells the same and doesn`t sound any different when I let off after full (21 psi) boost maybe I was expecting to much or it maybe better with an auto (mine is a 5 speed)

PS. yes i`m ASC certified

 

ASC huh? I'm ASS certified... LOL

 

I have driven it much today, might notice more tomorrow, no biggie $12 dollars and fifteen minutes, worth a try

 

you notice it more if your un-tuned after the GM tune it takes all the sensors to their max pretty much. But let the car learn it and see?

 

I installed the spring this past weekend, when iI removed the piping to gain access to the spring I noticed an oily residue at the bottom elbow of the piping. This must be the same oily residue that the tech at the dealer said was caused by my drop in K&N filter and resulted in them wanting to charge me close to $300 for a new filter and MAF sensor. That trip to the dealer was back in Feb, haven't been back since. I was having all kinds of problems with inconsistency in boost levels. Sometimes it would hit 20+psi and other times only 12-15psi and sometimes 0psi and it would throw code P0101.....MAF sensor. Only seen total loss of boost once since then where it threw the same code. Still see some inconsistent levels though even after installing the spring. I have the GM tune on an auto. Took some pics but not sure how to upload them. Any thoughts on why I have this presence of oil in that piping?

On another note I'm looking at doing another mod but not sure which direction to go? Cat back 3'' hahn exhaust........or do I do the IC upgrade and piping? Which one in your opinion will I see the best performance gain? Looking to add a little more punch to the GM tune.