[domrep]

Were they able to do a pressure test for you? Can i ask which local shop this is?

[troylin]

right now I have green springs installed and wants to change to yellow springs as everyone has suggested, but I am having difficulty to unscrew the cap, it is so tight and slippery, tried all methods but still cannot get it off.

Is there any trick to get it off easily? Can someone help, thanks!

[EastBayE90]

Originally Posted by troylin

right now I have green springs installed and wants to change to yellow springs as everyone has suggested, but I am having difficulty to unscrew the cap, it is so tight and slippery, tried all methods but still cannot get it off.

Is there any trick to get it off easily? Can someone help, thanks!

I used the bubble wrap it came in and just wrapped it around the end. The rubber on metal will stick well and should allow you to spin the cap. It was pretty difficult. The trick is to use something that won't slip on the metal surface and won't scratch it.

[Elie335]

good to read, I just ordered a set from forge DV, does anybody knows if now they comes with the yellow springs instead of the green?

[troylin]

Originally Posted by (-(ellblazer420

I used the bubble wrap it came in and just wrapped it around the end. The rubber on metal will stick well and should allow you to spin the cap. It was pretty difficult. The trick is to use something that won't slip on the metal surface and won't scratch it.

Thanks so much!

Finally got my yellow springs fitted!

[MikeVictor]

Originally Posted by Elie335

good to read, I just ordered a set from forge DV, does anybody knows if now they comes with the yellow springs instead of the green?

You should get all three sets, the green ones will be installed already. What you'll need to do is unscrew the end caps and install the yellows as per the instructions. There's a "how to" on the Forge Motorsport website.

A reply to an email I sent to Patrick at Forge about spring selection contained the following,

"The springs aren't effected by maximum boost pressure so much as the pressure differential between where they are mounted and the pressure seen at the reference line connected to the manifold. A setup that sees 20 psi max with a pressure drop of 1 psi will use a softer spring than a setup running 10 psi with a drop of 3.

Real world testing of the different springs is the best way to determine what will work best with your setup."

[Elie335]

Originally Posted by mattyv

You should get all three sets, the green ones will be installed already. What you'll need to do is unscrew the end caps and install the yellows as per the instructions. There's a "how to" on the Forge Motorsport website.

A reply to an email I sent to Patrick at Forge about spring selection contained the following,

"The springs aren't effected by maximum boost pressure so much as the pressure differential between where they are mounted and the pressure seen at the reference line connected to the manifold. A setup that sees 20 psi max with a pressure drop of 1 psi will use a softer spring than a setup running 10 psi with a drop of 3.

Real world testing of the different springs is the best way to determine what will work best with your setup."

Thanks for showing the mail, now things are more clear....

but I'm not understanding/not sure what he meant by " pressure differential between where they are mounted and the pressure seen at the reference line connected to the manifold "

[DaFish]

thanks for this, I just ordered them !

[BMW1986]

Originally Posted by Belarus

Unless you provide the actual code it will be a speculative discussion. Since LIMP can be caused by many things, boost leak, mis-fire, over boost, HPFP, injectors and etc....

Interesting I pulled a bulletin this morning that discusses this code. The guys in my shop feel it could be the turbos going. I cleared the code and I want to see if it comes back. I installed the Yellow Springs from the start on my DV.

Originally Posted by RR80

Are you having the 5-10 map in the procede? the underboost code for the map is a known issue and 5-25 already fix that!

Yes, I am running the 5-25 Maps in my procede. The car doesn't seem like it has an odd/low boost issue.

[BMW1986]

Anyone had to get their turbos replaced with this code?

[**335i**]

in here http://www.ardesign.info/store/bmw-1...-ddv-kit.html# 2 options:

Anodized Black

Polished

which one most popular?

[Elie335]

Originally Posted by **335i**

in here http://www.ardesign.info/store/bmw-1...-ddv-kit.html# 2 options:

Anodized Black

Polished

which one most popular?

dude... are you serious? just pick your favorite color lol

[TT3 iN NyC]

I got the Stett Chargepipe with forged diverter valves. Are the dv's that come with the Stett kit the same as the ones mentioned here? Both springs included?

[M3 Eater]

I was running yellow for a while and decided to try the green again with a set of the tuning disks that come with each kit. I figure each disks should be good for 2 psi taking the green 15 psi spring up to 17. Thats where I run and the car feels smooth. The yellows made the car leap forward quickly when I stepped on the gas but put a shit load more back pressure on the turbos. A very popular DV company claims that a car should use the lightest springs possible to remove as much back pressure as possible.

Your spring change that fixed your leak may have just been you re sealing the Forge unit to an air tight seal and prob had nothing to do with the color of your springs.

[Alpina_B3_Lux]

Originally Posted by TT3 iN NyC

I got the Stett Chargepipe with forged diverter valves. Are the dv's that come with the Stett kit the same as the ones mentioned here? Both springs included?

Yes, they're the same. I'm running that setup (don't know which spring though, was too long ago that they've been installed).

Alpina_B3_Lux

[TT3 iN NyC]

Great info in this thread. Got the Stett Chargepipe with forged diverter valves installed this passed Saturday with ETS fmic and Stett CAI. You can definitely notice a difference but it's not substantial. I believe I'm running the green springs that came pre-installed. Once I install the PROcede and dps, I'm going to switch to the yellow springs to be on the safe side.

[TT3 iN NyC]

Originally Posted by Alpina_B3_Lux

Yes, they're the same. I'm running that setup (don't know which spring though, was too long ago that they've been installed).

Alpina_B3_Lux

Thanks for your response! :-)

[G.I.Joe]

Just thought I'd take the time to thank the OP and others for making this thread.

I had the new design Forge DV installed about 2 months ago, and initially I just had them installed in the original chargepipe with the gren springs. The guy who installed them said he had never heard of any problems with the gren springs and basically thought I was a bit nuts for wanting the yellow ones. Big mistake! I don't know how on earth Forge could have tested the fit and approved it. Terrible boost leaks from both DV's. Car ran pretty bad in the mid range, lost about 5 whp top end and frequently caused a limp due to 30FF fault (boost leak).

At any rate, I then ordered a STETT CP (very nice build quality), but am I the only one wh wonders why on earth the two mounts for the Forge DV's are so close together that the Forge DV basically cannot fit? I ended up making one tube longer than the other, so the new design Forge DV's would still fit sorta' one on top of the other.

Well, I still got the occasional 30FF code and a limp, usualy around 3000-3200 rpm. I never got the supplementary springs with me from the shop, and after several attempts to have him send them to me, I contacted the local Forge import office about buying a new set of yellow springs. Well, they basically started out by telling me I didn't need them and that they would have to order them from the UK etc. At this point I was all out of patience, and insisted that they just get me the springs. Turned out they actually had them in stock and could ship the same day......

I have now had the yellow springs in for a little over 2 weeks, and I have been pushing as hard as I could, and NO limp modes, NO more 30FF code.

Only good that has come of all this trouble and investnment, is that I now have a CP that is prepared for meth.....

I think I would've gained more performance from a cat-back exhaust, probably spend less money, and had a LOT less trouble as well.

The car is performing very well now, but honestly, I think for me, the Forge DV's has pretty much been a waste of money.

[yawn]

So I couldn't help but bring this thread back to life...

It seems that the general consensus here is that the more boost you run, the higher the spring rate you will need to prevent any leaks.

However, it seems that there is evidence out there to suggest that vacuum causes the valves to open - boost has nothing to do with it. In fact, boost is actually keeping the valves shut. Regardless of whether you're running 8psi or 20psi, the valve is shut. So shouldn't that mean that the spring we choose for these DVs (or any DV or BOV for that matter) should be entirely dependent on the vacuum we're pulling? Unless boost affects vacuum somehow...

[Deveray]

OK so this is a very old thread - but I have a new theory that could explain what people experienced. I am interested because I just got the Forge N54 diverter valves and was wondering what springs to use (for a Cobb stage 1+).

So here goes: each valve has 2 major hose connections, one underneath the (spring loaded) piston and one to the side. Looking at the fitting instructions today, it seems clear that the side connection is to the charge pipe (the inlet to the valve), and the one underneath the piston is the discharge. This means that whatever the boost pressure gets to in the charge pipe, the valve cannot be pushed open against the spring because the high pressure is above and to the side of the piston seal. The spring merely returns it after the vacuum actuation of the valve has opened the piston. But what if the valve is fitted the wrong way around (the hoses are the same size)? The high pressure from the charge pipe is now pushing underneath the piston against the spring, so that the boost pressure is able to overcome the spring pressure, it can move the piston, opens the valve, and you get a leak at high boost as described by the OP.
The OP's problem could have been solved because stronger springs prevented this, or alternatively that the mechanics doing the fitting had to look at the instructions to open the valves to change the springs.... and realized that they had put them in the wrong way but kept mum about it.
If this interpretation of the operation of the valve is correct, then the spring strength is only important during a gear change: the piston is immune to boost pressure from the side during a high boost pull, but the valve opens when the throttle is lifted off, and the spring re-closes it afterwards when the throttle is reapplied. At that point the boost pressure is indeed underneath the piston and the ratio of spring to boost becomes important to re-close the valve. So if the valve is fitted correctly, a too weak spring would only cause a delay in re-boost after liftoff (not desirable but relatively benign), and if fitted incorrectly would cause a boost leak constantly during a high throttle pull (more serious). The latter seems to fit the OPs observation more accurately.
So I will stick with the original (green) springs when I fit them.
Just interested in your thoughts on this theory.

[skyotee]

I installed Forge DVs a few months ago, correctly oriented , with the stock green springs installed. Running MHD Stage 1+. No issues.

[shlai]

Originally Posted by Deveray

OK so this is a very old thread - but I have a new theory that could explain what people experienced. I am interested because I just got the Forge N54 diverter valves and was wondering what springs to use (for a Cobb stage 1+).

So here goes: each valve has 2 major hose connections, one underneath the (spring loaded) piston and one to the side. Looking at the fitting instructions today, it seems clear that the side connection is to the charge pipe (the inlet to the valve), and the one underneath the piston is the discharge. This means that whatever the boost pressure gets to in the charge pipe, the valve cannot be pushed open against the spring because the high pressure is above and to the side of the piston seal. The spring merely returns it after the vacuum actuation of the valve has opened the piston. But what if the valve is fitted the wrong way around (the hoses are the same size)? The high pressure from the charge pipe is now pushing underneath the piston against the spring, so that the boost pressure is able to overcome the spring pressure, it can move the piston, opens the valve, and you get a leak at high boost as described by the OP.
The OP's problem could have been solved because stronger springs prevented this, or alternatively that the mechanics doing the fitting had to look at the instructions to open the valves to change the springs.... and realized that they had put them in the wrong way but kept mum about it.
If this interpretation of the operation of the valve is correct, then the spring strength is only important during a gear change: the piston is immune to boost pressure from the side during a high boost pull, but the valve opens when the throttle is lifted off, and the spring re-closes it afterwards when the throttle is reapplied. At that point the boost pressure is indeed underneath the piston and the ratio of spring to boost becomes important to re-close the valve. So if the valve is fitted correctly, a too weak spring would only cause a delay in re-boost after liftoff (not desirable but relatively benign), and if fitted incorrectly would cause a boost leak constantly during a high throttle pull (more serious). The latter seems to fit the OPs observation more accurately.
So I will stick with the original (green) springs when I fit them.
Just interested in your thoughts on this theory.

I am not an engineer but I think I know high school physics very well. I have read in many forums that the orientation of the DV does not matter, i.e., either ends can be the inlets. Even STETT told me the same. But I have put lots of thought and experimented the DV by disconnecting the outlet (of course plugged the pipes to the turbo) so that I can hear when the DV opens. I have the same conclusion as yours. The orientation does matter, at least for the FORGE DV design. This whole thing of green vs yellow springs is kind of misleading and is irrelvant if a DV orientation is the same as stock.