Losing boost, Forge recirc spring advice needed

[xyber 1]

Just found im losing loads of boost through my forge 007, its only been fitted for 1500 miles and seems the green spring has worn out already as it seems alot softer that it first did, so spoke to forge who are sending me a yellow spring to try and sort it

Has anyone had this problem before

What colour spring are you using

What psi is your charger running

Where have you connected the vac line from the valve to

Thanks all

[cadguy77 0]

I'm using a blue on a 8psi pulley, no probs over the last year.

[xyber 1]

Ive just been out and had it apart and cleaned it up and the spring has definatly gone, really soft now and just spits out more air the more revs you give it

Plus side is with the new spring in and full boost, it should be more fun again with that initial "woohoo thats better!" moment

[xyber 1]

I'm using a blue on a 8psi pulley' date=' no probs over the last year.

[/quote']

Thought I remembered you mentioning that back along

Good rule of thumb then probably, your boost pressure x 2 (ie 8psi boost = 16psi spring)

[Lizard Racing 0]

I use a red spring now as the green one I had was leaking boost.

[xyber 1]

Ive been hunting around and it seems that a 6psi is its own force that it can exert on the piston/diaphram, so Its probably been leaking for ages and ive only just noticed now the weather has warmed up abit and ive got the windows open and heard the noise

quote from the forge site

Please Note:

The quoted spring pressure (Psi) relates to the un-assisted clamping force of the spring and should NOT be taken as an equivalent to boost pressure when determining suitability. Once a valve is fitted to a car it is subjected to various pressures that act upon the diaphragm or piston to aid its respective ability to seal or hold boost. An example of this, would be when using a FMCL007P valve on a 1.8T engine as found in the TT 225hp. The boost pressure on a "chipped" car can peak at 26psi. The recommended spring would be the Green or Yellow

[xyber 1]

Problem solved, yellow spring to the rescue, getting a proper bit of dumpage now when letting off I get a bit of a pssshhh, where as before only got that when giving it some

Wish I could go and try it out to see if there is an increase in boost but Ive done my back in, which is nice ;-(

[cadguy77 0]

glad you got it sorted

[xyber 1]

Cheers cadguy, just out of interest do you know how this valves work

They open off throttle to recycle the boost, but when your back on throttle do they close straight away or do they gradually close and then open instantly again off throttle?

Mine seems to close gradually, although that is stationary and not under normal loads

[cadguy77 0]

under throttle the valve is closed by the spring, so when you come from off throttle/vacuum to on throttle/boost the valve should close instantly minimising boost leak thru the valve.

Which way round have you installed your valve? bottom port to downstream charger side and side port to upstream charger side (if you get what i'm saying?)??

[xyber 1]

yep, in through bottom port, out through side

vac hose connected to the spare port on the brake booster line

so the second you hit the throttle it should close and let no boost through?

[cadguy77 0]

That's the way i see it, but i'm no expert. The spring needs a fair bit of vacuum to pull the spring up (dependant on spring rating), so unless you're hoovering around the magic vacuum figure to pull your spring then it should clamp closed under any lesser vacuum/boost conditions

[xyber 1]

Ill just have to keep and eye on it I suppose, feels alot better, accelerating alot more aggressivly so im pleased with the fix, cheers for your help mate

[cadguy77 0]

NP