Question for Forge DV Owners

[PeteRR]

Quick question chaps. For those running mostly stock engines/boost, which spring do you have fitted in your Forge Diverter Valve?.
Mine came supplied with a yellow one after telling Forge I had a standard 12 psi of boost pressure.

I seem to get a lack of response (possibly lag?) after a change up of a gear under full throttle. Would I be better off with the weaker green Forge spring for a stock engine?

(The valve doesn't seem to give any noise at all under wide throttle changes, is this usual?. I want to make sure its actually working!)

[jameswkr]

Pete. Is it a piston or diaphragm type ? Which way round do you have it installed ( std or reversed ? ) Are you sure the connections are leak free ? ( Have you checked the hard pipe (behind the cam belt ) is transferring boost/vacuum ? How long was it installed before you noticed potential problems ?

[PeteRR]

Hi James,
It's the piston type of valve (FMCL007P or something like that).
I first installed it upright (if you can imagine on a ur) as the original, with the vac. pipe connection uppermost and the right angled port connected into the air intake hose.

This gave a bit of a noise when lifting off (suppose it does work then), but it wasn't really a good noise so I reversed the valve and now its silent.
I could do with checking the pipe you mention (if the ur has one). The other connections are checked regulary and most vac. hoses are new (a 4mm SFS one on the DV). I have a boost gauge which is telling me I'm getting full boost under full throttle (approx. 0.85 kg/cm2) and lots of vacuum when lifting off.

The car pulls like a train low down and when on boost, but when I change up and go again it seems a bit flat. (though the gauge indicated heathly boost). Just wonder if it is lag or another issue. (plugs, leads, lambda, maf, frequency valve etc. are all basically new).

According to the Forge website the Yellow spring is meant for higher boost pressures than I have, but Forge originally said its ok. What do you reckon?

[jameswkr]

Pete, what fuel are you using ? If your boost gauge says Ok and the car is not performing maybe the knock sensors are retarding sparks ? You appear to have re installed as standard ( with boost hitting the side of the piston ) - how long has the Forge been on the car ? When was it last serviced ? Have you got a spare DV to test against it ?
I have had bad experience with sticking piston DV and have gone back to latest S3 Bosch as recommended by Mr Cotet...

[PeteRR]

James, I am using BP Ultimate at the moment (though the ur 20V is designed for 95 octane unleaded, 91 with loss of power).
I was using a S3 valve but I had a problem with it (poss split diaphragm) though I'm thinking now that it was installed the wrong way round. I do still have the original valve I might try. The Forge has been on for a few months now and the car is over-serviced if anything (oil every 3K miles etc.).

Talking of knock sensors, one significant thing is that I recently had a new dizzy fitted. I found that I initially had only half the proper boost pressure, probably due to misalignment. I had it readjusted, but wonder if it is actually spot on, though boost pressure is correct? (Where exactly is the 'window' to check flywheel position?)

[jameswkr]

Pete, its not the petrol then...unless you had a bad fill. Sorry, I meant servicing the DV. If its only been on a few months it "should " be ok. I'm ABY so not very familiar with dizzy but the flywheel window is on NS of bellhousing. I recall a special plate mounts over the distributer ( with the cap off ) to set initial rotor position ..lots of other sites with more info on this ( I am sure others will chime in ASAP ). Did you check your Bosch DV with Mityvac /other to prove its really US? The spring in mine is much stronger than the one in my piston DV.

[PeteRR]

Cheers James, yeah, the DV has not been touched since fitting it, I may take it off and check its movement, and I could really do with getting the Mityvac with a gauge (I have the one without at the mo) to check both the old DV's.

Also want to confirm all the timing criteria is correct. Had a quick look previously but couldn't see the 'window'.

[volcano rs]

peteRR once you fit the dizzy you only have to turn it enough to start the car, you cant adjust the timing from the dizzy after that. the ecu does that .

[jameswkr]

Err..not sure about that. There is a recent post in the RR section on the quattroforum where tweaking the basic setting has restored lost boost....

[PeteRR]

Yeah, that was me!....it pulled like a train until boost hit about 6 psi and then nothing.
Got that sorted, but the dist. setting may still not be perfect.

[jameswkr]

Aah, should have sussed the location - Cheshire "PeterB" = "PeteRR"