bs

For all of you who own the Forge diverter valve I was just wondering if you had cracked it open to see which spring was inside? I installed mine in both orientations and experienced an annoying screeching and fluttering noise when it released. So out of curiosity I cracked it open and it had the blue spring inside, which from Forge's site appears to be the third stiffest spring. At anyrate I have the yellow spring(weakest) so I installed it and I'm going to go test it out. FYI I also have an AVCR set at 1.4kg/cm2 for the street and 1.5kg/cm2 for those special occasions so the boost is slightly higher than stock.

JeffWels

I too get the fluttering no matter what orientaion, although I don't get any screatch sound. I was under the impression that from forge the DV's came with the softest spring available. I would assume the fix to the fluttering would be a stiffer valve not a softer one? If I take the car to redline and shift I get a large blow off surge then a more slight flutter. like a pshhhhhh psh. hahaha only way I can describe it.

Jeff

KK

iTrader: (4)

Fluttering is usually a sign of compressor surge, which is bad. You'll need a lighter spring like bs mentioned. I'll be opening my Forge DV to see what spring was installed. I do have the yellow to test as well and a boost gauge so I can let everyone know if I see any boost leaking.

Mark

timzcat

iTrader: (10)

Mine came with Green which I guess is one stiffer than yellow.
Works really well, no flutter or anything. Nice and smooth.
Still running stock boost levels though. FYI

tpm17

iTrader: (38)

I was gettin the most annoying fluttering sound after I installed my RMR Air filter kit. I immediately removed the Forge DV and installed the stock BOV. The stock BOV releases in one nice swoosh, although the sound is incredibly quiet. I immediately called Forge and ordered their tuning kit. Curious to see what spring I had in my DV to my amazment I found it was blue. I thought KK said in his Project Evo write up that Forge DV come with the softest spring which was green I believe. If I"m getting the fluttering sound which should I replace the blue spring with? A softer spring or a harder spring?

2Cool

Weird... I am not up to undoing all the allen bolts to check my Forge spring, but I get only a very loud sigh/sneeze sound with the RMR intake. I do mean loud, as in a lot like a VTA valve.

bs

mine sounded almost like tires screeching.......people i was passing probably thought i was chirping the tires in all gears The blue spring does seem to be to stiff and the yellow seemed to work much better. For those concerned that the softer spring won't hold boost as well that doesn't seem to be a concern. I don't know maybe the green one is really the right one, but all i have is the blue one that came in the valve and the yellow one. it is interesting that people are getting the same valve for the same car and it is coming with different springs.....must be where we got them from. where did you guys get yours from? i picked mine up from vivid

tpm17

iTrader: (38)

Mine came with blue directly from Forge and they gave me no other springs. I had to pay $20.50 for the spring tuning kit which will be arriving today and I guess I'm going to have to test them all to see which one work the best.

tpm17

iTrader: (38)

I just got my tuning springs from Forge and they kinda ****ed up. They gave me a yellow spring, red spring and blue spring but I already have blue. I gotta contact them about this. I installed the yellow spring and there is no more fluttering sound, but I also have a question. With my tuning springs I also received 3 disks the diameter of the springs themselve. What do I do with them? I got no instructions with the springs.

RENN-ART

iTrader: (11)

The shims are meant to fine-tune the spring tensions of the springs you have.

For example, if you wanted something not as hard as the blue spring, but a little harder than the yellow or green spring..

The order of tension is as follows (not down to a science, but pretty good theory to follow):

Yellow = softest (for lower boost applications)
Green = soft (good overall spring for most boost applications)
Blue = hard (for most 20+psi boost applications)
Red = very hard (for very high boost applications)

ForgeMotorsport

I am looking into this right now. Our latest batches of valves have all come in with blue springs. I know our own EVO 8 has the VTA with the blue spring in it. I have run the recirc valves with the blue spring and it was fine, although way too quiet. I will test the yellow and green springs in the recirc valves on our car tonight, if it doesn't rain. Unfortunately, our car is still stock, except for the valve, so it may not be able to duplicate on cars with intake, exhaust, boost controllers, etc....

tpm17

iTrader: (38)

Forge didn't give me a green spring and I have the yellow installed. Am I screwing up my car??? I hope Forge sends me the green spring they didn't send me in my tuning kit.

FORGE PLEASE HELP!!!

ForgeMotorsport

Actually, green is the softest, then yellow, blue, and red. The Tuning kit is shims, yellow, blue, and red springs. This is due to the tuning kit being for VW and Audi valves which come with the green spring.

TPM17, give me your name and i will get you a green spring sent out today.

If you call, please specify EVO valve and I will discuss this with everyone at Forge to make sure we know which valve we are assembling a tuning kit for. We are looking at changing the pricing and including all the tuning kit springs and shims along with the valve. We have also just made a new piston to stop the "dead bird" sound, as one of our customers called it, on cars with aftermarket intakes. If anyone would like to try it out please give me a call with your info and I can get one of those out to you.

We stand behind our valves with our 100% warranty. If there is any issue, we will take care of it. Feel free to email or call me if anyone has any issues.

timzcat

iTrader: (10)

FYI to everyone.
I spoke to Tom at Forge and am getting the new piston and I ordered the spring kit for my DV valve. I will report back here how everything goes with it.
I am currently running green and am planning on trying the blue.
This is on stock boost.
For the squeak noise I will try the other piston and see if it eliminates the noise.

Tom,
I had a thread a while back about the advantages and disadvantages of two DV valves.
Basically it boils down to the advatage of getting rid of more air at once thus being better for the turbo as far as surge and allowing the turbo to continue spinning as fast as allowed because there would be less pressure in the IC to inhibit it.

The disadvantage would be the total loss of pressure in the IC pipe might affect performance when the throttle is opened back up after a shift.

It's a matter of how fast a turbo that is spinning at it optimum speed can rebuild the pressure when the valves close, versus a turbo seeing more resistance from the pressure in the pipe, but that same pressure is advantages for performance.
The two valves could also be independently sprung to open at slightly different rate. Ideally you would thing two would better protect the turbo, the question is at what performance cost.

tpm17

iTrader: (38)

KK do you have a report on the testing of the different springs you said you might do? Talked with Tom from Forge and I must say they are really top notch people. They're sending me out the green spring which I did not recieve in my tuner kit, and we had a nice long talk about the different results people are seeing from their DVs. I currently have only an RMR air filter kit and the blue spring was causing a fluttering sound. I installed the yellow spring today and everything is great, but I'd like to know if I'm leaking boost pressure with a really soft spring. Tom said green is the softest, then yellow, then blue, and lastly red is the stiffest.