[s-cars] While we are on the subject of WGFVs...
Strangconst at rogers.com
Wed Jan 11 21:37:21 EST 2006
I undo my post, I can't read or type tonight... I'm taking my toys and going
----- Original Message -----
From: "Mark Strangways" <Strangconst at rogers.com>
To: <s-car-list at audifans.com>
Sent: Wednesday, January 11, 2006 8:23 PM
Subject: Re: [s-cars] While we are on the subject of WGFVs...
>I kinda don't see it that way.
> I always felt that the wastegate would only see boost when the WGFV is
> open or energized, otherwise it see the "vacuum" stream on the inlet side
> of the compressor. I am not 100% convinced that there is enough vacuum
> generated to do much good.
> That has been discussed to death in previous emails, and I ain't going
> there with out proper ammo :-)
> Mark S
> ----- Original Message -----
> From: "Theodore Chen" <tedebearp at yahoo.com>
> To: <Djdawson2 at aol.com>; <bob at chips-ur-s.com>; <s-car-list at audifans.com>
> Sent: Wednesday, January 11, 2006 8:15 PM
> Subject: Re: [s-cars] While we are on the subject of WGFVs...
>> are you sure that's how it works on the UrS4/S6?
>> i agree with your description of the configuration, but
>> note that the WGFV is plumbed to the lower chamber of the
>> the WGFV has three ports on it. the left port goes to the
>> wastegate. the right port goes to the turbo intake. the
>> bottom port goes to the turbo output. normally, the
>> bottom port is connected to the left port and air can pass
>> freely. normally, the bottom port is not connected to the
>> right port and air cannot pass between these two ports.
>> when the WGFV is actuated, all three ports are connected
>> to each other. i verified this by applying 12v to the WGFV
>> and blowing through each of the ports.
>> the way the wastegate is plumbed on the UrS4 is that boost
>> is used to open the wastegate. if the ECU wants more boost,
>> the ECU implements this by actuating the WGFV, thereby bleeding
>> boost off into the intake. if the ECU never actuates the
>> WGFV, all the boost from the turbo goes to the wastegate
>> and the wastegate will open at the default pressure.
>> --- Djdawson2 at aol.com wrote:
>>> The WGFV is basically a switch used to control the boost level at which
>>> WG will open. It is also used to "increase" or "decrease" the
>>> strength of
>>> the WG spring when required.
>>> There are 3 ports on the WGFV. 1 of the ports goes to the wastegate,
>>> basically is the means by which the ECU's desires are communicated to
>>> The other 2 ports provide the ECU the mechanical means to either
>>> or "weaken" the wastegate spring. 1 of those 2 ports goes to vacuum,
>>> at the turbo inlet. The other 1 goes to boost, found on the scroll of
>>> turbo's compressor housing.
>>> If the ECU decides that all conditions are good for high boost
>>> the WGFV allows the vacuum source to pass through it to the WG, and this
>>> effectively increases the WG's ability to remain closed. Net result...
>>> remains closed to a higher boost level than would be attainable with the
>>> If the ECU decides that conditions are not good for high boost
>>> the WGFV begins to cycle the boost port open, allowing boost to pass
>>> to the WG, and this effectively decreases the WG's ability to remain
>>> Net result... the WG remains closed to a lower boost level than would
>>> attainable with the spring alone.
>>> If you take the ECU out of the picture by removing the WGFV, or
>>> disconnecting the line to the WG, you will find that the stock WG spring
>>> allow about
>>> 14-15psi of boost. If you are running a header, you will discover that
>>> stock WG spring is capable of holding the WG shut up to 25-28psi of
>>> This can only be due to the fact that the exhaust restriction, and
>>> pressure built up between the cylinder head and the turbine, is greatly
>>> Hope that helps,
>> Do You Yahoo!?
>> Tired of spam? Yahoo! Mail has the best spam protection around
>> S-CAR-List mailing list
>> S-CAR-List at audifans.com
> S-CAR-List mailing list
> S-CAR-List at audifans.com
More information about the S-CAR-List