Forge BPV

[Skywlkr]

What color springs is everyone using that has a Forge BPV?

 

[1quickturbosix]

Blue + 2 shims... though I just switched to blue + 1 shim.. didnt notice anything

 

[FMFDoc85]

just finished the install. blue with 1 shim. have yet to test drive. This is from forge's website:

Valve Spring color coding


Green - 5-15 PSI


Yellow - 15-23 PSI


Blue - 23-30 PSI


Red - 30 + PSI

 

[Marauder.45]

Where would I find more about this without asking noob questions in this thread? (angel)













Are you running that much boost? Or do you run the blue for safety?

Decided to do it anyway!(upyours)

 

[patty AT forge]

just finished the install. blue with 1 shim. have yet to test drive. This is from forge's website:

Valve Spring color coding


Green - 5-15 PSI


Yellow - 15-23 PSI


Blue - 23-30 PSI


Red - 30 + PSI

That info is really only applicable to the VW/Audi 1.8T engine. Here is my generic cut and paste MS3/6 reply to spring questions:

"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."

 

[Blendercloud]

This does help. Thank you.

 

[Marauder.45]

good answer (yippy)

 

[FMFDoc85]

That info is really only applicable to the VW/Audi 1.8T engine. Here is my generic cut and paste MS3/6 reply to spring questions:

"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."

My bad guys, thought I pulled it from our part number, didnt mean to mislead.

 

[FMFDoc85]

if it means anything.... been running blue with one shim for the last week and its doin great. I think i got the very few of one stock bpv that leaked. boost is great.

 

[FMFDoc85]

cuase believe me, i dont want to screw anybody over sorry if my info was misleading, i was trying to avoid it and had checked sources, i guess i was still wrong.....see you guys at eecmm?

 

[Blendercloud]

Blue, two shims.

 

[MX5RACER]

Can anyone tell me the correct way to put the shims in? Does the shim go above or below the spring, or does it not matter?

 

[Blendercloud]

Put them below the spring. If you'll notice, above the spring on the cap of the BPV there is a seat for the spring to sit in.

 

[FMFDoc85]

Put them below the spring. If you'll notice, above the spring on the cap of the BPV there is a seat for the spring to sit in.

same as i did

 

[vrspeedemon]

I running yellow with 2 shims right now...think I might switch back to blue or blue + a shim or 2.

 

[Qwik6]

Blue no shims here.

 

[wannabe]

i ran yellow for a while (way it shipped to me from Ken) and then switched to blue and then blue with a shim. i recently noticed the blue with a shim kinda sputtering a bit more, so i dropped back down the the yellow, but it seems to release quicker/not hold as well.

i'll probably settle on blue no shims.

patty: is there any type of maintenance needed for those of us fiddling with the springs? do we need to lube anything or something when changes are made?

 

[Mistersix]

blue with no shims. seems to be the best balance between civility and strong boost response.

yellow seems to be the best one to start out with. sometimes i'd even throw the stocker back on for comparisons sake. gives you a better idea of what you goin fur!

 

[ukrms6]

I running yellow with 2 shims right now...think I might switch back to blue or blue + a shim or 2.

stupid question ... but how do you change the springs?

 

[Flightmedic]

stupid question ... but how do you change the springs?

Just unscrew the cap of the BPV and the spring pops right out. Put the new spring in and then screw the cap back on and voila your good to go.