Reversing DV

[simonelman]

An interesting post by Forge Motorsport on VWVortex

"We are reliably informed by VAG senior engineers that the reason the
OEM bosch valves are fitted the way they are IS because of the noise.

In the original position they are less efficent but quieter."

So reverse the DV so it runs horizontally it will hold the boost longer run
more efficently and sound better.

This applies to all Audi DV`s

Simon S3MTM

[johneroberts]

Someone else has mentioned this to me annd apparently...most have been fitted the other way around...funny that they have only just notified everyone
[img]images/graemlins/smirk.gif[/img]
cheers
jr

[Paul-RS]

And i have seen other posts on the South African Audi club sites by Andre (audi nut) about problems with them being fitted wrong way round from factory...

concluded vacuum hose should be uppermost, as intended...

[s2driver]

I had to do this.

I bought a secondhand one (with a new ally piston). Re-built it, fitted to car in the same orientation as the original and it would peak at 1 bar (instead of 1.15 ish). Noticed the lack of boost instantly.

I contacted Forge by email to ask if the spring was strong enough and whether they could sell me a replacement, stronger one. Same day I had a response and they stated to first try reversing it. If that didn't work they offered to send me a load of springs to try. Failing that they promised to send me a brand new unit free of charge.

Swapping ports over sorted it but I must say I was totally impressed with Forge. Offering to send me a new unit in return for a second hand one! Top company [img]images/graemlins/clap.gif[/img]! Can't comment on fitting instructions....I didn't have any.

[Doug_RS2]

I have a forge one and i think i've noticed a drop in performance - which way round id it in an S2. I have a new standard one that I was going to swap in - just to check it was that.

Thanks

[s2driver]

I will take a photo of the way mine is installed over the weekend and post it for you to see. Not sure how clear it would be because it is extremely tight where it is situated.

Check all of your hoses too if you are suffering boost problems: easiest place to look and the cheapest to fix yourself. I have a pressure tapping teed off just before the ECU which I can plug my 5inch industrial, calibrated pressure gauge to see how boost is varying with loads and temperatures.

(need to get that VAG-COM ordered so I can get more telemetry!!)

[Doug_RS2]

I have VAG-COM but it doesn't log boost pressure on the S2.

[Joshie]

Have a look at this link.
http://home.attbi.com/~mistertam33/THE_ ... e_FACE.htm

it tells you all you ever wanted to know about DV's and the benefits of reversing them. Seems that some models when reversed will enhance performance and can be reversed (like Forge's) and others while reversing will not damage anything there will not be a performance benefit.

I serviced mine about a month ago - there seemed to be more of a whoosh under full boost after servicing, but the issue I have been having is that I sometimes get power drop off - lifting off the throttle end then gently edging the power on cures it but I am convinced that the DV or DV's are sticking. I was considering reversing them or trying the new latest Bosch ones for about £16 each - anyone know the model number?

Otherwise here is the link to the full resource for the 2.7 Bi Turbo engine which is a font of knowledge.
http://www.s4biturbo.com/

[Paul-RS]

The post i referred to...

Click Here. SA audi forum

[Joshie]

Acording to the diagram in the link DV's fitted to all RS4's and S4's by Audi are the wrong way around - this can't be right. In fact if they are fitted as suggested with the vacuum pipe end pointing upwards the S4 - biturbo cover will not be able to seated in place.

I beliebve that the vacuum pipe end pointing upwards is definately the wrong way around for this reason.

Yesterday I checked my Forge DV's - one is not holding the vacuum and I need a servicing kit with new rubber seals to remedy this. In the meantime I am using the original Bosch DV's which are working perfectly.

[Paul-RS]

certainly the s3 item is upper most like pic. Mine hasnt been touched from factory...

[johneroberts]

The benefit is non existant ... the only difference is that it makes more noise [img]images/graemlins/smirk.gif[/img]
I have spoken to a couple of people"In the Know" and they concurr.
Cheers
jr

[Joshie]

Yeah but the point surely is that there is no right or wrong way as far as Audi are concenrned anyway - in the [img]images/graemlins/s3addict.gif[/img] the DV is positioned with the vacuum hose end pointing up and in the S4 / [img]images/graemlins/rs4-button.jpg[/img] the DV is positioned with the vacuum hose horizontal. [img]images/graemlins/confused.gif[/img]

[qquattrO]

Gentlemen,

While it is possible that different orientation of the DV on some (??) cars will not make much difference apart from the noise, do not allow anyone to mislead you into saying there is no real orientation. There always is! Just think for a second what the purpose of the dump valve is and then visualise which way the pressurised air travels to and from the intercoolers, etc. and you will soon realise it is pretty well defined what connects to the top, side or bottom ports.

q.

[toasty]

I was considering reversing them or trying the new latest Bosch ones for about £16 each - anyone know the model number?

Just bought some myself from VAG Parts the code is 034 145 710B (apparently £20.09+vat each)

I also went for the following just in case:

# 078 133 356T (1 off) (Throttle Body Boot)
# 078 133 343 (1 off) (main clamp for TBB)
# 078 133 343 A (2 off) (small clamps for TBB boot)
N 904 11901 (1 off) (boost sensor clamp)

Came to about £60 in all.
-Dan