Which WGFV?

[waad_uk]

Hi Guys,

I am thinking about fitting a new WGFV to see if it cures my sometimes variable boost. I have seen in the past some people have used an S3 WGFV as opposed to the original S2 one...

What are the pros and cons of using an S3 one?

[Jamo]

Hi mate, do you mean dump valve?

If so yes it is better than the stock one, i personally use an aftermarket Forge one and also have a dahlback one on my avant.

The WGFV is the waste gate frequency valve which the ecu uses to control boost pressure.

[waad_uk]

Hmm, perhaps it was the S3 WG they used.

So I should just go for the standard WGFV (Which is what I want to change)

[S2central.net]

Are you sure you aren't getting your WGFV mixed up with your TBV ?

I know some folk use the S3 TBV as its supposedly more robust than the S2 item.

The WGFV (solenoid thing with three pipes) is vehicle specific due to location and size of the three pipes. Functionally they are all the same with two inputs (entry and ext side of compressor) and single output (to WG)... The 3B WGFV is angled differently from ABY... I dunno if an S3 WGFV would fit the ABY, but even if it did I would expect no difference in performance versus from a fresh ABY one.

If you have the original WGFV on the car, then its DEFFO worth renewing it - they can be electrically perfect after years of abuse but what does degrade over time is the WGFVs ability to modulate the on-off instructions from the ECU quickly enough so as to control boost properly...

If you have a WGFV that moves too slowly then it can result in target boost pressure not being achieved... by nature of the mechanical spring in the WG taking more control than it should - which results in lower boost due to Audis failsafe design.

Paul

[porkkis]

OT

Actually I find it a good idea using the newer and faster WFGV from 1.8t. The software should of course be changed so the boost level would be the same with the different valve.

1.8t guys are using S2 valves to get slightly increased boost. Doing the opposite with proper mapping sounds like a good idea to me

[Fat Audi 80]

I changed the WGFV and the TBV at the same time (both with standard ABY parts) and noticed a slight increase in boost holding ability in the upper rev range and a smoother gearchange as a result. Well worth £50 and an hour with drivers side headlight out...

[waad_uk]

Cheers Guys. Yeah, I must have been getting confused when I read a previous post.

I have just ordered up a Std WGFV from VAG Parts, so we will see if it improves things....

[iain1067]

S3 valve is the one i have and works with no probs