Got this in the mail today... now I can go WOOOOOSH!!!

[[email protected]]

Got a Forge 004 to replace the 007 that no longer recirculates to the TIP.

Anyone know what color spring is inside the unit by default?

[romell]

yeah thats it.. .its really easy

and its sounds SEXY

[7speed]

hey I just baught one of those today as well ! What spring will you be using ? I installed and instantly missed the sound of Splitter valve

[onceover]

willing to sell your 007 to me?

[7speed]

oh and it doesnt go woosh ! it's like a low pitch whistle

[romell]

^ why you didnt lik how loud it was?


and im guessing when ou have the Revo BT file... you can run a BOV with no problem right?

[7speed]

My splitter valve was buku loud, the 004 not so much, but it sure is pretty

[romell]

^ haha

sweet.

[[email protected]]

Well the open dump to atmosphere of the 007 just sounds like a blast of air so I assumed the 004 would sound the same.

I can understand how it would whistle due to all the small holes the air has to pass through.

I was planning on running the yellow spring with one or two shims.

[A4 Moda]

oooh looks like a spaceship

[A4 TSCHUSS]

oh and it doesnt go woosh ! it's like a low pitch whistle

weird mine sounds nothing like a low pitch wistle. It is a chhh chhhhh sound.

[dougyfresh]

What ever happened to Darth Vader?

[A4 TSCHUSS]

^ why you didnt lik how loud it was?


and im guessing when ou have the Revo BT file... you can run a BOV with no problem right?

you can run a bov no problem with a chipped car, a ko4 car, a gtrs car or a gt3076 car. Contrary to the belief of what you heard from someone else who heard it from someone else, the car works fine with a bov.

Ask A4ringedone8t, he ran a 004 on his car with k04, gtrs, 3071, 3076.

[dougyfresh]

weird mine sounds nothing like a low pitch wistle. It is a chhh chhhhh sound.

Like this?
http://www.youtube.com/watch?v=BQpa8whzwAE

[[email protected]]

weird mine sounds nothing like a low pitch wistle. It is a chhh chhhhh sound.

I'll find out tomorrow when I have it installed.

Did you change out your spring? Or did you order it with certain spring in it?

What ever happened to Darth Vader?

Darth is on the operating table

[dougyfresh]

Darth is on the operating table

Why? He already is Anakin. No need to operate..

[[email protected]]

Why? He already is Anakin. No need to operate..

He needed a new hat

[A4ringedONE8T]

Youll need the yellow boost spring and the heavier vac spring which you will have to call Forge directly and ask for

[A4ringedONE8T]

you can run a bov no problem with a chipped car, a ko4 car, a gtrs car or a gt3076 car. Contrary to the belief of what you heard from someone else who heard it from someone else, the car works fine with a bov.

Ask A4ringedone8t, he ran a 004 on his car with k04, gtrs, 3071, 3076.

I had the 004 with APR 1, 1+, K04, and the REVO GTRS and never had single problem, around 40k miles on those 4 setups

[J-jizzle]

Got a Forge 004 to replace the 007 that no longer recirculates to the TIP.

Anyone know what color spring is inside the unit by default?

I believe yellow. At least thats what mine came with. My car is stock so I put in a green spring and the car didn't like it on start up. Because where the car idles higher while it is warming up the green spring was to weak and would stay fully contracted not allowing the 2nd pistons spring to stay stiff enough to hold in the slightly extra pressure in the system. My experiences lead me to believe they put yellow in all the 004 standard. (hope my explanation makes sense)

I did however ask forge for stiffer vac spring like A4ringedONE8T said but they sent me the same one I had, so I stuck with the big Yellow spring and the original vac spring.

[[email protected]]

Youll need the yellow boost spring and the heavier vac spring which you will have to call Forge directly and ask for

Well I got the yellow spring but what is the vac spring you mentioned?

[J-jizzle]

Well I got the yellow spring but what is the vac spring you mentioned?

take it apart and you will see. It is the spring for the little piston under the big piston that keeps the system closed when the car is at idle.

[[email protected]]

Curiosity got the better of me so I got an allen key and went to work.



Look like the yellow spring is the stock unit now.



Here is the vacuum spring. So why does this need to be upgraded?



According to the Forge website this is the valve spring color coding

Green - 5-15 PSI
Yellow - 15-23 PSI
Blue - 23-30 PSI
Red - 30 + PSI

So I'm going to throw a shim I have from my Forge spring kit in there and I should be set!

WOOHOO!

Can't wait for tomorrow!

[A4 TSCHUSS]

Did you change out your spring? Or did you order it with certain spring in it?

didnt change anything.

[Phorte]

we can't wait either ;) put up some videos asap!

[mike-2ptzero]

It shouldn't matter which spring you use seeing that the 004 is a dual piston, so it isn't open at idle anyway. The springs doest effect how much boost you can run seeing thats why there is a vac/pressure hose connected to the top.

[[email protected]]

Then why do they offer a spring kit for the unit if it makes no difference in operation?

[A4 Moda]

Yeah I was always confused about how a bov was rated by "pressure".

I thought the vac line was there so that when your car engages boost, the vac line introduces, equal but opposite boost levels to keep that piston/diaphram from opening.

the purpose of the spring would be the counteract idle vacuum. AKa, when the car is sitting at a light the spring helps keep the piston from getting sucked open.

Winston, i've never used a forge Anything before. But, if your car holds a strong idle, and you don't hear compressor surge then you should be perfectly fine.

Z

[[email protected]]

I always get confused as well when I think about how these simple things work... just too simple I think.

I sucked on the upper nipple and watched the large piston move up but the smaller second piston stayed shut.

The I did some searching and found this description on Audiworld: http://forums.audiworld.com/a4/msgs/2239859.phtml

Now let's talk about the dual piston normally closed under vacuum BOV by forge. This valve while under vacuum by the intake signal at idle will stay shut as the first valve lifts up but the second stays shut this allows all of the air that was measure at the MAF before passing the BOV to make it's way into the intake. This valve will not cause your vehicle to run rich nor cause your vehicle to stall or even damage your motor in any way. The trick is to know how a DV works and why a BOV is bad and how the forge BOV does not have the problems associated with the Japanese's valve so in an effort to educate everyone we are going to make a video and provide a visual online.

So when there is vacuum in the system the main piston is pulled up from the suction on the top nipple. The bottom piston stays shut as the little spring keeps the system closed sealing the intake pipe.

When the system is in boost then the boost in the pipe pushes against the top of the main piston and at the bottom piston after it pushes the bottom piston out of the way. Equal and opposing as you put it.

When you lift the vacuum pulls the main piston up and the residual boost blasts out.

Where I still get confused is what does the main (the big yellow) spring do? Is its purpose purely to close the main piston after discharge?

[A4 Moda]

So when there is vacuum in the system the main valve is pulled up from the suction on the top nipple. The bottom valve stays shut as the little spring keeps the diaphragm closed and sealing the intake pipe.

That part confused the hell out of me. LOL
Okay, so for the sake of clarity, I'm going to refer to the following parts of the BOV:

1. White hat valve: HAT
2. Silver Phat cylinder: Piston
3. Pipe that comes off the Turbo Exit hose where the BOV will be installed:hose
4. Upper body portion of the BOV with the Nipple on it: TOP
5. Lower body portion of the BOV attached to the HOSE: Bottom

As I mentioned, I have no experience with this particular mechanical item, but here's my understanding of it, from your pictures and from Mr. Ecode's expose/

The Hat, is what keeps the PISTON closed at idle. The spring for the hat, (small spring) is pushing against the PISTON in order to get leverage to keep the vac line plugged. At the same time, the piston is in the closed position. Why does it stay there? it's the YELLOW spring that's pushing up against the inside of the TOP BOV body that's keeping that valve in the closed position. Yes you don't need the Yellow spring there, right? If the car also idles perfectly and the piston doesn't open, then why is the YELLOW spring there? The previous statement assumes that the piston will never open. HOwever, as you well know, the piston does open (every time you let out the throttle). As a direct consequence, that piston opens and you get a BOV sound.
But what happens after it opens? Of course, that's where the yellow spring comes in. It pushes the piston back in place. Thus, the car will hold idle and keep boosting after you let off the throttle.

But wati!?!?! If, at idle, the vac line is plugged by the HAT, how in the heck is that any different from when I let off the throttle? Why when I let off the throttle does the Piston open, and not when i'm at idle. Only thing I can think of to defuse this paradox is the little window of opportunity I like to call the vacuum margin. It may already be called a technical name, but this helps me remember. Vacuum at idle and vacuum right after you release the throttle is different.

Idle Vacuum: 18-20 in/hg
throttle vacuum: 20-24 in/hg

This is where I think the throttle vacuum sucks up the entire assembly altogether and purges the boost.

So you see, any BOV/DV, should be tuned for vacuum, NOT boost.

And, if i'm reading this correctly, the springs in the 004 are very fine as far as tuning.

The Hat spring is going to be tuned for 18-22 in/hg (IDLE)

Yellow spring only marginally stronger, at 22-24 in? perhaps. (Throttle )

[[email protected]]

Lets see if 2 blind mice can figure this out

At idle the system is in vacuum. The piston is sucked up due to the vacuum that is supplied to the TOP. I was able to suck the piston completely open just by attaching a vacuum line to the nipple on the TOP and sucking on the line. I connected the vacuum line to one of my boost gauges and I registered a max reading of -10mmHg so the -22mmHg at idle the engine makes will open the piston no problem.

When I remove the vacuum from the TOP the yellow spring pushes the piston down closing the BOV



Here you can see the HAT closed due to the spring pushing it down.





When the car is in boost the piston is pushed down due to the boost coming in from the TOP. Boost is also entering from the Bottom as the HAT is now pushed aside and equal but opposing boost is keeping the piston from opening.

When you lift the throttle the TOP is now in vacuum lifting the piston and venting the pressurized air from the hose. When all of this air is gone the HAT is pushed down by the spring sealing the intake pipe until you enter boost again.

I agree that the HAT spring must be tuned for vacuum at idle.

So the big yellow spring does nothing except push the piston back down? Hence Mikes comment above that the type of spring in there makes no difference?

Then why would they offer a spring kit for this unit?

[mike-2ptzero]

Then why do they offer a spring kit for the unit if it makes no difference in operation?

For setups that might have a different pressure drop and compression ratio. Not all cars are going to have the same vacuum when lifting off the throttle or a difference between the amount of boost at the IM vs the amount of pressure/boost at the bottom of the valve. A car with a setup that has a higher pressure drop will need a stiffer spring to keep the valve closed.




As for your question in your last post. The larger spring will still have an over all effect on how much pressure is being put on the HAT since both springs are pushing down on it. So the amount of pressure being put on the HAT is the total of both springs not just the lower one. This way you only need to make changes to the larger spring to effect both the piston and HAT.

It seems the piston is actually just there to make a seal so the vacuum can decrease the spring tension on the hat and then seal off the outlet holes during boost. The lower spring just allows for some give so that the piston has more travel.

[romell]

for shawn and s4 tushchss(sorry if i hacked it)


i ran a forge 004 when my car wasnt chipped. it ran fine for like 2-3 days then it started sputtering threw a code and went into limp mode.. is that casue i wasnt chipped or mabe my car doesnt like it... btw im revo.

[mike-2ptzero]

for shawn and s4 tushchss(sorry if i hacked it)


i ran a forge 004 when my car wasnt chipped. it ran fine for like 2-3 days then it started sputtering threw a code and went into limp mode.. is that casue i wasnt chipped or mabe my car doesnt like it... btw im revo.

Did you check to see what codes were thrown?

[romell]

=( no...

im scared to run it again cause i really dont want to throw a code.

[[email protected]]

So I installed the 004 this morning and it was simple swap where the 007 used to be.

I started the car and the main silver piston retracts and I see the smaller piston pushed down against the bottom.

Too the car for a spin and the discharge is a bit louder now that the air blows off in all directions vs. through the side vent on the 007.

I think I might have had a small vacuum leak as well when running the 007 venting to atmosphere for the last couple of weeks as the system isn't completely closed so I was running a tiny bit rich. AFR went from 14.7 to 13.7.

I've cleared the fuel trims with VAG and see how the AFR reacts now.

[J-jizzle]

for shawn and s4 tushchss(sorry if i hacked it)


i ran a forge 004 when my car wasnt chipped. it ran fine for like 2-3 days then it started sputtering threw a code and went into limp mode.. is that casue i wasnt chipped or mabe my car doesnt like it... btw im revo.

When did it sputter (at idle?) What color spring where you running? From my previous post I said that a green spring is to weak for the car when It warms up yada... yada... yada....I put the yellow spring back in and all was fine.

[Sp3C14L 3D]

sorry i dont know too much about the forge valves, my buddy just gave me a 004 and its decently loud. Is the splitter louder than the 004? and if so why? i know its a newbish question but hey im curious?

[7speed]

Yeah the splitter is way louder than the 004. My splitter was crazy loud. The splitter vents through a horn and the 004 through small circles.

[[email protected]]

Well I decided to move up to the Tial 50mm BOV as I still get a flutter.

Who wants a like new 004 or 007p?