[lfelunden]

So I see many people around do the BOV DIY mod to hear any leaks on the DVs. I don't even have to lol, I can hear them leak sometimes even without the BOV mod - I hear a whistling sound and when it's gone at WOT, car just pulls hard.

I got yellow springs in my forge DVs, mounted on an ER chargepipe.

Any fix for this crap? I'm really tired of them, I unplugged them today and put in grease, that didn't help either. Has anyone experienced the same? If yes PLEASE tell me what the fix for it was.

[Dmacc]

Originally Posted by lfelunden

So I see many people around do the BOV DIY mod to hear any leaks on the DVs. I don't even have to lol, I can hear them leak sometimes even without the BOV mod - I hear a whistling sound and when it's gone at WOT, car just pulls hard.

I got yellow springs in my forge DVs, mounted on an ER chargepipe.

Any fix for this crap? I'm really tired of them, I unplugged them today and put in grease, that didn't help either. Has anyone experienced the same? If yes PLEASE tell me what the fix for it was.

I would contact forge and get a rebuild kit. It comes with grease, new pistons, and o-rings.

[Jeff@TopGearSolutions]

Originally Posted by Dmacc

I would contact forge and get a rebuild kit. It comes with grease, new pistons, and o-rings.

That or sell charge pipe and go Tial, less maintenance.

[lfelunden]

Originally Posted by Dmacc

I would contact forge and get a rebuild kit. It comes with grease, new pistons, and o-rings.

It's brand new!

[Dmacc]

Originally Posted by lfelunden

It's brand new!

I had a similar problem with mine, I rebuilt them and they still made the leaking sound. Turned out to be a vacuum issue.

[OB]

how does your logs look? sure it's not a brittle vacuum hose or something else?

[Marcadelic]

I'm having a problem with my ER pipe too but I'm on stock DV's

[Wes335XI]

Originally Posted by Jeff@TopGearSolutions

That or sell charge pipe and go Tial, less maintenance.

Tial all the way!

[lfelunden]

Originally Posted by Dmacc

I had a similar problem with mine, I rebuilt them and they still made the leaking sound. Turned out to be a vacuum issue.

All my vacuum hoses should be new aswell.. Where did you locate the problem?

[lfelunden]

Originally Posted by OB

how does your logs look? sure it's not a brittle vacuum hose or something else?

Boost oscillations post gearchanges and at wot it just don't push me directly forward, there is minor pause then suddenly the power just comes lol

[lfelunden]

So I think I will try this:

That's basicly what is happening right now I guess

[lfelunden]

Originally Posted by OB

how does your logs look? sure it's not a brittle vacuum hose or something else?

http://datazap.me/u/lfelunden/alpina...log=0&data=1-4

Here is a log of my car, it's not even hitting max boost until redline

[ajsalida]

Did you install the DV's pointing the correct way? It is easy to install them with flow backwards (ask me how I know this). Top of valves with Forge logo should be facing each other and the vacuum ports pointing towards the engine. Like this

[whosdady]

Originally Posted by ajsalida

Did you install the DV's pointing the correct way? It is easy to install them with flow backwards (ask me how I know this). Top of valves with Forge logo should be facing each other and the vacuum ports pointing towards the engine. Like this

So what happened while you had them the wrong way? Any damage or lack of performance? Why did you even think to check? I better check mine

[ajsalida]

Originally Posted by whosdady

So what happened while you had them the wrong way? Any damage or lack of performance? Why did you even think to check? I better check mine

There were no directions, even the ones on the Forge website were not clear, and the CP I bought did not have the holes in the same place as stock. Also I had to disassemble and put the right springs in, so I was looking at how the valve worked and couldn't figure which way they were supposed to go. Put them on and then kept looking for pictures, realized I'd done it wrong.

I am not sure it matters, the valve is vacuum operated, but it seems like one way it works with boost, the other way against it. No damage I can tell.

The way it works is, when the throttle is closed quickly under heavy boost, and there is vacuum inside the intake manifold, the valves are supposed to open and let the boost pressure off from the other side of the throttle so it doesn't bounce back into the turbos. It dumps off the excess compressed air into each intake tract pre-turbo. Going one way the flow in the valve is easier than the other, I cannot remember now which is which. Bottom line is you end up with either a bit too much transient boost or too little, but the valves still work. Under normal conditions it doesn't matter.

I never understood how the springs worked, and this may be part of it if the flow is not an issue. The spring holds the valve closed and basically determines how much vacuum you have to pull inside the intake manifold before the valve opens, and then how fast it closes once vacuum is gone. You put the valves in backwards and it messes that rate & trigger level up. It does not prevent them from opening or closing.

Now this may be more of an issue to get right with more aggressive tunes and mods, somebody who knows more than me about it could chime in on that. I think/hope the worst that could happen is the valves behave like you have the wrong spring in there and maybe make strange noises, perhaps trigger overboost faults etc. But it won't blow up.

edit: I seem to remember now that one (wrong) way depending on how strong the spring is, the boost could force the valve open WITHOUT any vacuum. Essentially like a wastegate spring but in the intake tract. That was the wrong way. It is supposed to be a diverter valve that only opens under overboost on abrupt throttle closure (hence the vacuum line). If you had it set up the wrong way depending on what your boost level was valve might be opening all the time once boost exceeds spring force and you may never hit proper boost levels. Would make noise too.

edit 2: OK here, this is what I finally found to install correctly:

http://www.namotorsports.net/docs/FMDVBM35B.pdf

The spring sits inside a sliding cup, the open end of the cup + spring faces the end of the DV with the vacuum nipple. Vacuum sucks against spring inside volume of open end of cup. The big end of the DV near the nipple is what should connect to the boosted part of the intake tract, exposing inside of cup to vacuum but preventing boost from pressing against other end of cup. If you reverse that the closed bullet end of the cup inside the DV is exposed to the high boost area, and thus can be pressed open by boost against spring pressure. Then it functions as a blow off valve (just boost opens it mechanically), and to some extent still as a diverter valve (vacuum still opens it but since boost is helping press against it, too soon). The problem is it seems like the spring was far weaker than whatever area of piston * peak target boost PSI was so it would always open too soon under normal operating conditions, ie as a very weak BOV.

[lfelunden]

Originally Posted by ajsalida

Did you install the DV's pointing the correct way? It is easy to install them with flow backwards (ask me how I know this). Top of valves with Forge logo should be facing each other and the vacuum ports pointing towards the engine. Like this

Hey.
I have the newer models, but aren't they vacuum operated and will that really matter??

[lfelunden]

Originally Posted by ajsalida

There were no directions, even the ones on the Forge website were not clear, and the CP I bought did not have the holes in the same place as stock. Also I had to disassemble and put the right springs in, so I was looking at how the valve worked and couldn't figure which way they were supposed to go. Put them on and then kept looking for pictures, realized I'd done it wrong.

I am not sure it matters, the valve is vacuum operated, but it seems like one way it works with boost, the other way against it. No damage I can tell.

The way it works is, when the throttle is closed quickly under heavy boost, and there is vacuum inside the intake manifold, the valves are supposed to open and let the boost pressure off from the other side of the throttle so it doesn't bounce back into the turbos. It dumps off the excess compressed air into each intake tract pre-turbo. Going one way the flow in the valve is easier than the other, I cannot remember now which is which. Bottom line is you end up with either a bit too much transient boost or too little, but the valves still work. Under normal conditions it doesn't matter.

I never understood how the springs worked, and this may be part of it if the flow is not an issue. The spring holds the valve closed and basically determines how much vacuum you have to pull inside the intake manifold before the valve opens, and then how fast it closes once vacuum is gone. You put the valves in backwards and it messes that rate & trigger level up. It does not prevent them from opening or closing.

Now this may be more of an issue to get right with more aggressive tunes and mods, somebody who knows more than me about it could chime in on that. I think/hope the worst that could happen is the valves behave like you have the wrong spring in there and maybe make strange noises, perhaps trigger overboost faults etc. But it won't blow up.

edit: I seem to remember now that one (wrong) way depending on how strong the spring is, the boost could force the valve open WITHOUT any vacuum. Essentially like a wastegate spring but in the intake tract. That was the wrong way. It is supposed to be a diverter valve that only opens under overboost on abrupt throttle closure (hence the vacuum line). If you had it set up the wrong way depending on what your boost level was valve might be opening all the time once boost exceeds spring force and you may never hit proper boost levels. Would make noise too.

edit 2: OK here, this is what I finally found to install correctly:

http://www.namotorsports.net/docs/FMDVBM35B.pdf

The spring sits inside a sliding cup, the open end of the cup + spring faces the end of the DV with the vacuum nipple. Vacuum sucks against spring inside volume of open end of cup. The big end of the DV near the nipple is what should connect to the boosted part of the intake tract, exposing inside of cup to vacuum but preventing boost from pressing against other end of cup. If you reverse that the closed bullet end of the cup inside the DV is exposed to the high boost area, and thus can be pressed open by boost against spring pressure. Then it functions as a blow off valve (just boost opens it mechanically), and to some extent still as a diverter valve (vacuum still opens it but since boost is helping press against it, too soon). The problem is it seems like the spring was far weaker than whatever area of piston * peak target boost PSI was so it would always open too soon under normal operating conditions, ie as a very weak BOV.

I got the evolution racing chargepipe, DVs do not sit as in the stock CP. About the springs, I'm using the yellow one, but I also got that "coin" for extra tension. So is it possible to put in the spring in the wrong direction?? If so, which side is which

[ajsalida]

Originally Posted by lfelunden

I got the evolution racing chargepipe, DVs do not sit as in the stock CP. About the springs, I'm using the yellow one, but I also got that "coin" for extra tension. So is it possible to put in the spring in the wrong direction?? If so, which side is which

I have the ER pipe too, that was what was so confusing. The holes for the DV are not in the same place as stock, and stick in weird directions with the extra hoses. I did not use the coins or shims, whatever. Shims on a DV spring are like preload, will make it harder to open. If you take the bottom of the valve off, press the cup in with one finger then hold another finger over the vacuum hole. It should seal well enough to hold the cup in place (valve open IOW) against the spring pressure. In fact this is how you are supposed to re-assemble them without ruining the o-ring.

I don't think it is possible to install spring or cup wrong direction inside, but I may be wrong. The spring needs to be inside the cup, and the bottom of the cup (open end) pointing towards the vacuum line hole, so vac can suck against the spring and pull the valve open against spring force.

Then position the DV WRT the two big external hoses so the pressurized post-FMIC part of the intake tract is NOT open to the blunt (closed) end of the cup. The blunt end should point to the air filter/intake pre-turbo side of the intake tract.

[lfelunden]

Originally Posted by ajsalida

I have the ER pipe too, that was what was so confusing. The holes for the DV are not in the same place as stock, and stick in weird directions with the extra hoses. I did not use the coins or shims, whatever. Shims on a DV spring are like preload, will make it harder to open. If you take the bottom of the valve off, press the cup in with one finger then hold another finger over the vacuum hole. It should seal well enough to hold the cup in place (valve open IOW) against the spring pressure. In fact this is how you are supposed to re-assemble them without ruining the o-ring.

I don't think it is possible to install spring or cup wrong direction inside, but I may be wrong. The spring needs to be inside the cup, and the bottom of the cup (open end) pointing towards the vacuum line hole, so vac can suck against the spring and pull the valve open against spring force.

Then position the DV WRT the two big external hoses so the pressurized post-FMIC part of the intake tract is NOT open to the blunt (closed) end of the cup. The blunt end should point to the air filter/intake pre-turbo side of the intake tract.

Could you post a picture of your setup please?

[lfelunden]

Originally Posted by ajsalida

I have the ER pipe too, that was what was so confusing. The holes for the DV are not in the same place as stock, and stick in weird directions with the extra hoses. I did not use the coins or shims, whatever. Shims on a DV spring are like preload, will make it harder to open. If you take the bottom of the valve off, press the cup in with one finger then hold another finger over the vacuum hole. It should seal well enough to hold the cup in place (valve open IOW) against the spring pressure. In fact this is how you are supposed to re-assemble them without ruining the o-ring.

I don't think it is possible to install spring or cup wrong direction inside, but I may be wrong. The spring needs to be inside the cup, and the bottom of the cup (open end) pointing towards the vacuum line hole, so vac can suck against the spring and pull the valve open against spring force.

Then position the DV WRT the two big external hoses so the pressurized post-FMIC part of the intake tract is NOT open to the blunt (closed) end of the cup. The blunt end should point to the air filter/intake pre-turbo side of the intake tract.

I don't understand the last part of what you've stated.
I have changed the springs - not a problem.

[ajsalida]

Originally Posted by lfelunden

Could you post a picture of your setup please?

It looks just like the pic above, except the DV's are farther apart. I would have to disassemble air cleaners, hoses, and so forth to get a good pic of mine. The ports that are not connected in the above photo then hook to the hoses that feed into the air cleaner (pre-turbo) side of each intake tract. The hoses that are connected in the above pic are connected to the charge pipe.

In the above pic the blunt end of the piston inside each DV is facing the unconnected (open) port. The open end of the piston and spring seat inside each DV face the connected port.

[lfelunden]

Originally Posted by ajsalida

It looks just like the pic above, except the DV's are farther apart. I would have to disassemble air cleaners, hoses, and so forth to get a good pic of mine. The ports that are not connected in the above photo then hook to the hoses that feed into the air cleaner (pre-turbo) side of each intake tract. The hoses that are connected in the above pic are connected to the charge pipe.

In the above pic the blunt end of the piston inside each DV is facing the unconnected (open) port. The open end of the piston and spring seat inside each DV face the connected port.

Check my next post for pictures