Adjusting A Forge Vta Dump Valve

[badbaz]

Can anyone advise on the best way to obtain the correct setting of this valve using the springs/shims? What's the correct way to achieve this? I take it you need a boost gauge to aid set up but can't get my head round getting it right!

My thinking is to get it a couple of notches above where it would leak under load but this isn't easily measured as far as I can see!

Help!

PS It's fitted to an Andy F mapped 05 STI, tried the red spring but it wouldn't dump, it's now got the blue spring it came with in and it dumps but want to be sure all's well. Any tips?

[badbaz]

No one know?

Has everyone else just got their fingers crossed?

There's gotta be a method, surely?

[AlanG]

Did Andy say there was a problem with the dump valve and suggest what to do to rectify?

[fiestajohn]

I had a Forge recirculating dump valve fitted to my car for a while, and I tried all the different combinations of springs and shims but I could never get it working right, so eventually I just put the standard one back on.

[badbaz]

Car was fine with original, just fancied the VTA one to go with the overrun banging and the rally decals, the whole package if you like, childish I know, but the car is not discreet to start with.

So, the new one on with red spring, no dump, this is bad as can wreck turbo I believe, red out, blue in and it dumps, not loud, but does dump. The thing is the car is differnet to drive now, it's more eager under light throttle and I'm wonder if my recirc one was done? Anyway, there's got to be a science to setting it correctly so who can tell all?