Dump Valves

[Pete_RS2]

I've had a weird noise on my RS2 since it was remapped. A foghorn is the nearest I can describe the noise which only comes on under boost. Tom (audiman) has heard it.

Anyway I took it to the guys at The Autopool today and they reckon it's a broken DV. I told them I put a brand new S3 one on there a few months ago & they said it probably wasn't the right thing to do (especially as it's now boosting to around 1.8 bar) as the S3 one was designed for lower boost so the spring pressure would be lower.

Which leads me to ask what DV's are the high boost guys using ? Are the S2 & RS2 DV's the same ?

[robo]

I use forge dv,

http://www.forgemotorsport.co.uk/content.asp?inc=product&cat=0006&product=FMCL007P

[DAVIDP20V]

I also have a forge one but I have the 006 ......

[alg]

Try a Forge diaphragm one. Saw it on website. Looked good to me

[PeteRR]

Hmmm, Dont want to highjack your thread, but I've recently fitted a S3 div. valve and have noticed a 'honk' sort of a noise, but only when the engine has just been started from cold and when the revs drop. (say when changing gear). I previously had put this down as a drive-belt noise or something.

Doesn't make the same noise after running for a few mins, but does seem to give an occasional 'whoosh' noise when lifting of the gas at high-ish revs, under boost.

Performance seems a bit flat lately too, but the boost gauge says its boosting fully.

Do you think it could be the valve?? ......time for a Forge??? (or the original one back in!).

[Doug_RS2]

The S3 one is better than any other stock one. It lasted fine on my car at 2.15 bar. Make sure it is the correct way round, as high boost and the wrong way round can tear them.

I use a Forge metal piston type most of the time.

[s2avant95M]

forge one for me too. its nice and shiny, thats the main thing.

[PeteRR]

The S3 one is better than any other stock one. It lasted fine on my car at 2.15 bar. Make sure it is the correct way round, as high boost and the wrong way round can tear them.

I fitted it in the same orientation as the original Doug, if thats right.
Just a bit concerned with the flat performance and 'honk' sort of noise when cold.

I'm assuming my car is standard, but it looks as if someones been in the wastegate as the plug covering the allen screw is missing.

[Pete_RS2]

The S3 one is better than any other stock one. It lasted fine on my car at 2.15 bar. Make sure it is the correct way round, as high boost and the wrong way round can tear them.

I use a Forge metal piston type most of the time.

It should be the right way round as Tom fitted my Samco DV hose recently. I'll probably order a Forge one and get somebody to double check at Billing.

[Martynf]

the honk was a classic sign on the early TT's that the DV had expired, as Doug says they should be fine, but make sure they are fitted the right way round, too easy to fit them wrong. Flat performance could easily be a dv expired yes. Yup, I too have used a Forge piston valve for the last 2 years with no issues at all. Forge ones work superb, just the cost is about 6x the price of a OE one!!

[audiman]

Petes car performs OK. No flat spots. I ran an S3 DV at 2bar+ for ages with no probs, but i quess it could be fooked. The car doesnt chatter on gearchanges tho. That is the main tell tale sign of a DV dead.

[HPmuirt]

Petes car performs OK. No flat spots. I ran an S3 DV at 2bar+ for ages with no probs, but i quess it could be fooked. The car doesnt chatter on gearchanges tho. That is the main tell tale sign of a DV dead.

Appologies to Pete_RS2 for the apparent highjack but my following dumb question sounds like your problem......

When I change gear, I get a strange noise, particularly if on some boost, but since I cannot really describe the noise (beyond the fact that it sounds like a knackered thrust bearing in a Triumph bell housing) I have never asked what it might be.

I had always hoped/assumed that it was actually the DV bleeding pressure out (since it is an Audi not a Triumph) rather than a problem. If this is the 'chatter' that Tom mentions, then does that mean my car is supposed to make this noise and therefore Pete_RS2's problem is indeed a dead DV?

Cheers n

Si

[Pete_RS2]

Petes car performs OK. No flat spots. I ran an S3 DV at 2bar+ for ages with no probs, but i quess it could be fooked. The car doesnt chatter on gearchanges tho. That is the main tell tale sign of a DV dead.

It does chatter now Tom. You get that 'fog horn' type noise when boost kicks in and then as soon as you lift off it chatters. That's what made the Autopool guys think it was the DV.

[audiman]

It never used to chatter tho did it?? I dont remember that

[Pete_RS2]

No I don't remember it chattering when you looked at it. I'll order a new DV & see.