Freeloader

Fitte a forge dumpvalve to my classic impreza about 12 monthes ago, all worked fine up until about a week ago when it seemed to only dump at higher revs??? Before i used to get a small dump at lower revs and a large whoosh when giving it some. now its only after about 4000 revs and it is at the same volume all the time.
Had a look round it ant it all seems fine apart from when i disconect the vac hose, you can see it close inside, cant remember it ever doing that before.
Could it be the spring thats fooked over time? or is there a way to adjust it?

IainMilford

iTrader: (15)

You can get different springs (weaker - stronger etc) to tune the valve. I've been experimenting this weekend with mine, I find that a harder spring makes less of a noise but holds the boost better, whereas a weaker spring dumps at lower revs, and is loud at higher revs, but IMO the car isn't as good to drive. You can get a spring tuning kit from forge for the right side of £20.

dunx

iTrader: (3)

You can add a shim to up the spring rate, a bit of silicon grease might loosen it up a bit.

HTH

DunxC

simb 2

iTrader: (3)

Give Forge a call Forge, ask for a service kit aswell as replacing the seals and re-greasing it may also solve the problem.

DaveW

Sounds like it just needs a clean and re-grease. I used to clean mine at every oil change (3-4k miles).

scoobaru86

iTrader: (1)

Same happend to mine the spring wore and got too soft. sort it quick or it could cause fueling problems like mine

IainMilford

iTrader: (15)

can you advise which grease to use, and which bit to grease please, I'm assuming its the big silver bit which the spring sits in. very technical I know

simb 2

iTrader: (3)

Just grease that and the seals and your away

IainMilford

iTrader: (15)

what grease do you reccomend?

MR_MAJ

On the subject iv got some issues with a forge dump valve not releasing (99 V5). Opened it up to find a blue spring, piston slides freely.

Im using a silicon samco hose for the vacumm pipe.

Reckon it needs a yellow spring?

IainMilford

iTrader: (15)

worth trying a yellow spring, it is softer than the blue one