S3 - Stock / Standard Quad Exhaust Flow - Should all 4 pipes flow the same.

[jungle650]

Morning...

Just happened to be wiping my exhaust tips whilst having the engine still running and noticed that the left outer exhaust pipe (passenger side) seemed to have very little (if any) flow from it.

I know the inner pipes seem to have the majority of the exit flow as these soot far quicker. But if I compare to the drivers side outer exhaust pipe for example, this seems to exhibit a decent amount of flow when compared to the passenger outer exhaust pipe. ( if that makes sense).

Now I know that there must be some residual flow out of it, as after a drive all 4 do exhibit some minor sooting, obviously the inner ones more. Normally I wipe my pipes down after every drive to make cleaning them super easy, but normally the car is off.. This time it was still running and noticed the above anomaly.

So my question is... Can any of you that happen to be out for a drive this morning / cleaning your cars, put your hand / cloth over each of your 4 pipes to check your standard / stock exhaust flow.. i.e. is the above normal?

Many Thanks
Jungle.

 

[rajeevx5]

The outer tail pipes are valved which are closed unless in dynamic mode above something like 3k rpm. Many people including myself have permanently opened the flaps using vcds or disconnnecting the connector. This makes the soot build up more even and makes the car sound better too

 

[jungle650]

The outer tail pipes are valved which are closed unless in dynamic mode above something like 3k rpm. Many people including myself have permanently opened the flaps using vcds or disconnnecting the connector. This makes the soot build up more even and makes the car sound better too

Thx .. Yes I have my valves open anyway via vcds. So I would have thought all 4 should see flow? Would be interested to hear those who have and have not opened valves what they can feel from the 4 pipes/ tips

 

[S32B]

Many people including myself have permanently opened the flaps

There's a joke in there but I better not

 

[GSB]

The gas flow at idle is minimal, and could easily be dealt with by just one of the tips. Given four to choose from, it'll be a case of going through whichever path offers least resistance. Its actually incredibly difficult to engineer a system that splits even two flow streams exactly equally, to split four flows equally without some mechanism for adjusting the balance is next to impossible.

 

[jungle650]

The gas flow at idle is minimal, and could easily be dealt with by just one of the tips. Given four to choose from, it'll be a case of going through whichever path offers least resistance. Its actually incredibly difficult to engineer a system that splits even two flow streams exactly equally, to split four flows equally without some mechanism for adjusting the balance is next to impossible.

Thx @GSB I do not dispute the theory. But very interested what others are seeing? Its interesting that I have 3 out of 4 flowing nicely on tick over. Come on @Rob2k68 , @batch , @jassyo06 , @RO65ERS ,@Simon L ... Anything for ne???

 

[batch]

Thx @GSB I do not dispute the theory. But very interested what others are seeing? Its interesting that I have 3 out of 4 flowing nicely on tick over. Come on @Rob2k68 , @batch , @jassyo06 , @RO65ERS ,@Simon L ... Anything for ne???

I haven't had the flap mod done, as I like the difference when you jab the throttle. But my middle two pipes are always worse. Not yet noticed any difference between these two?

 

[WarwickL]

I have had the flaps disabled (physically) and flow was as you say - irregular but out all four (right side outer less flow than left side outer).

I reconnected them some time ago (prefer the sound and the change in sound under throttle) and now very even - inner pipes more flow and equal, outer pipes less flow but equal.

 

[jungle650]

I have had the flaps disabled (physically) and flow was as you say - irregular but out all four (right side outer less flow than left side outer).

I reconnected them some time ago (prefer the sound and the change in sound under throttle) and now very even - inner pipes more flow and equal, outer pipes less flow but equal.

Thx guys.

Middle two pipes consistent and agreed always the worse as these have the majority of the flow- flaps open or not.

I will put the flaps back to normal via VCDS and see what I get. My 2 outer pipes do seem to flow differently to each other. Will also have to lay down on the floor and just check the pipes to make sure there isnt any obstruction.

Thx
Regds
Jungle

 

[Rob2k68]

With flaps standard ie connected I'd say both inners have 10-15% more flow than the outers - certainly warmer too.

 

[RO65ERS]

I've not driven her in the last 6k...which the mrs has done in 6 weeks! ...
i don't even know what tail pipes are anymore!

 

[RS3 S.]

Sorry to be a pain but could you please post the "flap open mode" through the VCDS system please?. Can't seem to find the link. Cheers guys.

 

[steeve]

Where's VEEEEEight when you need him?

 

[jungle650]

Sorry to be a pain but could you please post the "flap open mode" through the VCDS system please?. Can't seem to find the link. Cheers guys.

Exhaust flaps all open

===================
1 – Engine module
Exhaust Flaps deactivate
Byte 9
Bit 2 - Exhaust Flaps installed check box default activated – deactivate it and save as usual.

Rgds
Jungle

 

[RS3 S.]

Exhaust flaps all open

===================
1 – Engine module
Exhaust Flaps deactivate
Byte 9
Bit 2 - Exhaust Flaps installed check box default activated – deactivate it and save as usual.

Rgds
Jungle

.........thanks.

 

[jungle650]

.........thanks.

I have mine closed (ie back to stock) and the exhaust is quieter. Especially on a motorway run. But I do miss the increased noise, especially around town!

 

[Liquidfusion-S3]

I have mine closed (ie back to stock) and the exhaust is quieter. Especially on a motorway run. But I do miss the increased noise, especially around town!

Same here, I couldn't bare the humming noise so had to go back to stock after the VCD change.

 

[RS3 S.]

If you set it so the ''flaps'' are open all the time do you still get the exhaust ''fart'' on the up shift ?.

 

[jungle650]

If you set it so the ''flaps'' are open all the time do you still get the exhaust ''fart'' on the up shift ?.

Yes

 

[RS3 S.]

Thanks jungle.

 

[S3_Blue]

Is this any different to having the exhaust/engine set to dynamic on the individual mode?

Exhaust flaps all open

===================
1 – Engine module
Exhaust Flaps deactivate
Byte 9
Bit 2 - Exhaust Flaps installed check box default activated – deactivate it and save as usual.

Rgds
Jungle

 

[Rob2k68]

Is this any different to having the exhaust/engine set to dynamic on the individual mode?

Yes, even with dynamic I think they only opened dependant on throttle input and rpm so they are more noticeable with this mod. Also not sure if flap position is variable as open to just full open or full closed, I've had them open for a month or so now and quite like it - definitely less soot out of the inner pipes too!

 

[itsPaz_]

Should there be flow from all 4 pipes if the car is idle without disconnecting valves?

I've just disconnected my valves but can't hear any extra noise, in fact feels like i may have closed them by accident. However put car in efficiency and parked up, flow from all 4 pipes. Is this normal or would there only be flow from 2 pipes usually?

 

[jungle650]

Just the 2 inner pipes flow when the flaps are closed / left as per factory. They only open allowing all 4 pipes to flow when in Dynamic setting over 4k rpm or if you have completed the VCDS mod to artificially keep flaps open or physically unplugged them.

Jungle

Here is a vid

 

[-Ju-]

Just the 2 inner pipes flow when the flaps are closed / left as per factory. They only open allowing all 4 pipes to flow when in Dynamic setting over 4k rpm or if you have completed the VCDS mod to artificially keep flaps open or physically unplugged them.

Jungle

Or fitted a valve switch such as the ASR component RX1

 

[oli356]

Or fitted a valve switch such as the ASR component RX1

These things are so expensive for what they are.. I really don't understand why! It's just a remote to send a signal which tells the valves to open or close... How hard can that be :s but.. What do I know

(I have the AWE system which is equally as stupid)