Finally getting a Forge

[BrianFiebig]

OK, its official, the Paypal has been sent, and thanks to Pro5, Im getting my Forge BPV. NOW the eternal, Im sure much debated, and often searched for question:
Spring and shim combo.

Based on what Ive seen on Forge webpage, for a car with just the AEM/MSCAI with air straightener, the best option seems to be either Yellow w/ 1 shim or straight up with the blue, tho I would guess that getting the green and jamming both shims in there would get the boost right and let off the excess on shifts with a nice rushing sound.
Vote please, and post your thoughts.

 

[detonnation]

From Patty at Forge

Vacuum alone is enough to lift the piston in our valve even with our stiffest spring so the valve will open regardless of boost pressure with any of the springs. The only issue comes in very specific instances when manifold vacuum and charge pipe pressure are both very close to atmospheric and the pressure differential between the two are so low that the valve will "flutter" open and closed as that differential cycles back and forth around the pressure needed to crack the spring. Nothign to worry about as the forces involved are very low. That being said, here is my cut and paste "spring" reply:

The springs are used to account for variances in atmospheric conditions, and the relationship between boost and vacuum that different cars will see. To simplify it greatly the more boost that you are running the stiffer a base spring pressure you will need to compensate for the pressure differential between the manifold and the charge piping right at initial boost onset. Cars with few modifications running at or near factory boost seem to respond best with the yellow or blue springs. Cars running a bit more boost the blue and a few shims. The red spring is best used on cars running upper teens or low twenties.

That out of the way let me quickly go over how to adjust the valve. I recommend using three different spring tensions and performing some real world testing. Say for instance the yellow, blue, and blue with shims. Drive normally for a few miles (part throttle shifting, stop and go, merging and passing for some wide open data) then do a few wide open throttle runs. Do this with all three setups and compare the results, with "seat of the pants" or with data logging. If there is no difference use the softest setup. If the middle seems best that is the setup to use, if the stiffest works best perform the same tests with the next stiffest and compare.

That is the more complex answer. The easy quick answer is "use the blue spring if the cars is modified, if the car seems sluggish add two shims to the valve". 95% of the cars out there using the valve are using the blue spring.

Hope this helps. Let me know if you have any other questions.

 

[MikeHTally]

Blue +2

 

[john blutarski]

I used to use blue + 2 as did most of the people on here.

 

[PaPaSpeed]

I'm using the blue + 1, seem to work fine.

 

[Circle9]

Blue + 1 for me as well

 

[zx2man]

If your stock bpv isnt leaking and seems to be running fine, Would i be wasting my money if I went with a forge bpv?

 

[PaPaSpeed]

If your stock bpv isnt leaking and seems to be running fine, Would i be wasting my money if I went with a forge bpv?

You are never wasting money when you buy parts for your car, at least that's what I tell my wife.
Plus the looks alone are worth it.

 

[Silver Ecstasy]

I voted yellow+2 shims because it reacts the closest to stock while maintaining some good boost.

Blue+2 can be pretty rough to drive smooth, it shudders and hesitates a lot. The partial boost or the mid throttle on/off situation makes the car feel jerky sometimes.

 

[vrspeedemon]

yellow plus 2 shims when over 30 degrees, blue with no shims when below 30 degrees.....don't ask me why but just seems to work best for my speed6

 

[Silver Ecstasy]

yellow plus 2 shims when over 30 degrees, blue with no shims when below 30 degrees.....don't ask me why but just seems to work best for my speed6

That's an interesting philosophy. Technically speaking, you're going to run into boost cut in the wintertime anyways with the severe changes in temperature and pressure..so running a stiffer spring? Technically it's the other way around, atleast it is with the guys in my area. They tend to run Blue+2 in the summer, and remove the shims in the winter.

I liked the way yellow drove and i'm back to stock now and I like it the same, only it's so damn quiet..

 

[SPEED305]

yellow + 2 for me!

 

[karl hungus]

blue sans shims has worked for me. i'm too lazy to experiment.

 

[SomnoSpeed3]

I like the look and sound of these things. I just have MSCAI and the Cobb AP for mods. Is it worth it for me to get it from a performance standpoint? How about an all of the above standpoint? Combo of looks, sound, performance.
I don't think I can do it on looks and sound alone.

 

[detonnation]

I just installed mine. I went Yellow 2 shims. Seems to be running good. First thing I notice is the engine climbs nicely to 6k in first and second. Will take it out more later. I figured keeping it yellow since my only mod so far is the cpe SRI... Next will be a TMIC, maybe at the end of the summer...
Got the silver, looks awesome. Sounds cool and the engine seems more responsive. First gear was feeling a bit lazy after the cpe install, now its more responsive. Took all of 15 minutes! Im getting to think Im some kind of mechanic.. heh. Not really.
Mike

 

[Sport6]

yellow + 2 shims here.

 

[mr_mazda329]

I'm using just the blue spring. I may spike at 18 no or then.

 

[TKMS3]

So you are the person who beat me to the sale :mad:. Have fun with it

 

[240ka]

So you are the person who beat me to the sale :mad:. Have fun with it

theres another up for sale, go to the marketplace.

 

[BrianFiebig]

Hey, not my fault I sent a PM first. Besides, I got beat out onabout 10 before I got this one, not counting all of the forge and HKS units i got sniped on on ebay.
Looks to me like blue or blue +1 is the way to go...