Ordered VAG OE revision DV for S3

Since I have gone stage 2, I have noticed a marginal amount of DV flutter under full load.

One option was to back the boost off using the Revo Select switch, but that would be sensible and cheap. Instead I have decided to throw a few quid at the revised OE VAG diverter valve:

New revised DV (link - see bottom of page)







Older style DV (not my DV - web pics)






Ordered from JKM last night for about £50 inc postage. It looks OE, will raise no eyebrows when serviced, and should hopefully have better performance than the earlier revision version.

Will feedback with any observations once it's been fitted.

Cheers

Warren

DaveS3Turbo said:

How do you know what dv you have fitted. Mine being an 09 is it likely to have the newer oem dv fitted.

David

Click to expand...

Some time in '08 these became standard issue. Couldn't say when though, so yours is fine. On the pre revision ones, the orange gasket ruptured over time.

New DV arrived this morning, so I have used my lunch break to go and fit it. Truly is a 20 minute job at tops if your not taking photos of the task.

JKM sent the new DV for £40+VAT + registered next day post (around £50 in all), and here is a close up (including part number):



The major change to this revision D diverter valve is that there is no longer any soft perishable rubber bits on the plunger to overheat and be compromised. The new plunger head is hard plastic.

I also noticed when testing the plunger mechanism by hand, that they (the Japanese as its now made in Japan) have engineered a step into the piston action to create an initial friction in the movement before the valve then retracts. This is NOT present on the early unit which just opens freely. I am VERY much hoping this will remove any flutter.



I decided I wanted this to be an easy job, and wanted to do it without removing the engine cover. I have a Halfrauds Pro tool box (quantity as opposed to outright quality of parts), and this came in useful to build a very long tool to get to the bolts.



TOOLS USED:

T30 Torx
1/4" adaptor for attachments
Universal joint (1/4")
2-3 extenders (1/4" sized)
Ratchet or screwdriver handle (1/4")

JOB TIME: 15-20 mins
JOB DIFFICULTY: Simple

Now first I realised particularly with the larger intake, the torx bolts were not all accessible. However there is a hanger bolt which stabilises the DV unit against the engine bay (as you look into the engine bay from the front of the car this is the bolt furthest to the left but nearest the engine itself - you can't miss it, it's the only one with a black metal bracket attached to it). Take great care not to drop the bolt into the bay (like I did). Once this is removed, you can move the DV towards you to remove the remaining 3 torx bolts.

Picture 1 - Remove the locator torx bolt



PICTURE 2: Locator bolt removed


PICTURE 3: Use universal joint to get around obstacles to the bolts


PICTURE 5: Remove all torx bolts


COMPARING THE DV's

As you can see thre is a significant difference in the size of the heads on the plunger. Also the design concept has changed considerably indicating the 2008 revision unit was significantly flawed.



I decided to deconstruct the old style DV to look inside and see what made it tick. My valve was in perfect condition internally, but just purely lacked the capacity with the extra boost, to hold back the pressure until release was actuated.



I then refitted the new valve (YOU WILL SEE IN THE PHOTOS THERE IS A LITTLE MOUNTING LOCATOR LIKE A ROUND PLASTIC SPOT - ENSURE YOU LOCATE THE DV WITH THIS IN PLACE!!!), conducted the reverse of the above instructions, and reconnected the electrical contact connector to the head of the DV. I fired the car up, and started as sweet as a nut. No engine lights or problems, so when I go out tonight to see Stealth wagon hopefully I'll be able to give it a test and see if the stepped resistance of the new style DV can hold the boost better.



PLEASE BE SURE TO CHECK YOUR DV MODEL NUMBER BEFORE EMBARKING ON THIS MOD. I AM NOT CERTAIN WHEN IN 2008 IT WILL HAVE BECOME THE STANDARD ISSUE PART, BUT CHECK THE REVISION LETTER AT THE END OF THE PART NUMBER BEFORE BUYING ONE.

THE PART NUMBER OF THE LATEST REVISION DV IS MADE IN JAPAN PART NO: 06H-145-710-D
SEE BELOW

THE PART NUMBER OF THE EARLIER VERSION DV IS MADE IN GERMANY PART NO: 06F-145-710-C
(SEE BELOW)

As always, any questions just ask away.

Next mod, whiter daylight running bulbs!!

Flutter (appears) to be gone.

Need to give it one more proper caning at the weekend, but I honestly believe part of the problem with the OE DV could not maintain boost. Surge felt sustained and hard tonight, but then the air temp was much cooler so want to confirm this with warm day air temps.

Went to see Andy Oram (Big Andy S3 / Stealth) tonight, and that is a proper S3. Thread with photos to follow tomorrow. What a revelation. Made my car feel impotent!

Iggu said:

I'm not convinced about this. Although I now have a Forge I had my pre-revision OEM DV on whilst I was running both Stage 1 and Stage 2+ and did loads of Vagcom logging. The OEM DV held boost at steady pressures of 1.5/1.6 (even 1.7) right through the midrange and beyond. From the measurements I took the OEM valve has no problem holding pressure - even Revo Stage 2+ pressure on Boost 9. The only reason I have a Forge now is because I had an opportunity to get a new one for £40 and I like the noise - but the OEM DV was more than up to the job. The K04 turbo is maxed out at around 1.6 anyway.

Click to expand...

DV's on VAG cars have been notoriously unreliable for years. Some have been through so many revisions they end up half way round the alphabet.

I take your point with the above, but if the OE DV was up to the job, why would VAG spend the money having it redeveloped so radically away from the C specification. It's not 'value engineered' as such because the body is the same, just with different internals. If you talk to many tuners they will openly admit that it is a weak spot and a likely point of failure once you run significant upgrades. Because I wasn't logging the car at the time we heard the flutter noise I cannot confirm 100% that it was DV related, but both parties in the car immediately from the sound/characteristics said that it sounded DV like (and between us we must have 30 odd years of VAG experience - not to say that we were guaranteed to be right).

This thread is as much about highlighting the differences in the revisions as opposed to saying 'buy this DV, it will change your car for the better'. So far all signs on the 25 odd miles I have driven is that pick up is very slightly improved, and I don't seem to be getting the same flutter at the red line (but I caviat that with wanting to do more long term testing in more extreme conditions). Also I think in part this provides '07/early '08 cars an alternative to the Forge should their valve fail, as there aren't a surplus of Forge DV's kicking about at £40, particularly if owners are intent on keeping an OE look.

The OE DV may have been more than up to the job, but having perishable parts it is far more likely to fail. This option is less likely to leave you at the side of the road waiting for the 4th emergency service to coming rolling by.