Exhaust flaps (S3) - modify?

Itguy

Itguy

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Ok people, let's get some collective brain power on this one.


The exhaust flaps on our S3s must have a way of being tied open all the time surely - either electrically or manually with wire.


I'm interested in this because my inner pipes are such a PITA to clean, the bit of black soot seems to just weld itself on and I'm having to resort to fine wire wool every wash now.


I remember on the Aston V8 vantage it was a fuse that could be removed to leave them open all the time and I seem to remember there was something on the old RS3 that someone figured out.


Anyone got any ideas how they work on our cars? Anyone got their standard exhaust on the bench after having a whole new system fitted?


Are the flaps usually shut and then powered open or the other way around?


Cheers
 
Certainly on the R32 Golf I had you disconnected the pipe to the mechanism on the silencer and plugged it with something most people used a bolt.
Not sure if the S3 is the same, I'm sure some one on here will know.
 
Think you might need to use a proper metal cleaner rather than worrying about adjusting the exhaust system.

My A1 185 has the same issue with carbon heavy deposits on the exhaust. Really annoyed me when I got it as my Mk5 GTI never did it. In the end I found this stuff the best Meguiars NXT Generation All Metal Polish - Clean Your Car.

Over time fine wire wool will take the lustre away from the pipes. Using this stuff seems to build up a bit of a resistance for deposits sticking.
 
steeve said:
Certainly on the R32 Golf I had you disconnected the pipe to the mechanism on the silencer and plugged it with something most people used a bolt.
Not sure if the S3 is the same, I'm sure some one on here will know.
Click to expand...
That was using a vacuum actuator, same with the 8P S3. Just plug the vacuum pipe, and tie the valve flap rod open.


Unfortunately the 8V is an electrically actuated (motor) system. You could try unplugging the motor and see if it throws up any Faults in VCDS.


edit: Actually, don't do that. It may need VCDS to clear the fault code.
From memory, the flaps open at idle, then shut until around 3000rpm, then open again. In Dynamic mode, they might be open all the time? If you do force them open 100% of the time, you could get unwanted boominess in the cabin.
 
Last edited:
Pulp84 said:
Think you might need to use a proper metal cleaner rather than worrying about adjusting the exhaust system.

My A1 185 has the same issue with carbon heavy deposits on the exhaust. Really annoyed me when I got it as my Mk5 GTI never did it. In the end I found this stuff the best Meguiars NXT Generation All Metal Polish - Clean Your Car.

Over time fine wire wool will take the lustre away from the pipes. Using this stuff seems to build up a bit of a resistance for deposits sticking.
Click to expand...

Yep, that's the metal polish I've been using and it almost works but not really well enough and I certainly haven't been expecting to have to *polish* them every single week - wash yes! Polish no.
 
Itguy said:
Yep, that's the metal polish I've been using and it almost works but not really well enough and I certainly haven't been expecting to have to *polish* them every single week - wash yes! Polish no.
Click to expand...

I'm very surprised by that as it's fantastic stuff! Bit worried now for when mine comes!
 
I was thinking exactly the same the other day. I have VCDS so if anything needs resetting, that's ok, and I don't mind being a guinea pig. I thought the flaps opened >2500rpm or something like that?
 
Why don't you just set the exhaust to dynamic mode in the individual setting in the mmi to begin with?

I can confirm that when unplugged it does show an exhaust flap fault in vcds.
 
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RobH_S3 said:
Why don't you just set the exhaust to dynamic mode in the individual setting in the mmi to begin with?

I can confirm that when unplugged it does show an exhaust flap fault in vcds.
Click to expand...

I have and always have had it in this setting. It still seems as though the flaps only open at 2.5k revs.

Now I wonder if there is somewhere in VCDS that you can adjust the flap opening rpm?!
 
RobH_S3 said:
Why don't you just set the exhaust to dynamic mode in the individual setting in the mmi to begin with?

I can confirm that when unplugged it does show an exhaust flap fault in vcds.
Click to expand...

Did it make a sound difference with it unplugged?
 
Logging Measuring Blocks 245, 246 and 247 will tell you at what RPM the flaps are open or shut.

It's either fully closed, or fully (90%) open. No in between.
 
veeeight said:
Logging Measuring Blocks 245, 246 and 247 will tell you at what RPM the flaps are open or shut.

It's either fully closed, or fully (90%) open. No in between.
Click to expand...

Interesting. Thanks. I just unplugged what I assume are the flaps lol but not sure whether it's made a difference or not. I'll get VCDS and check what's going on
 
Ok we have fault codes

2 Faults Found:
21388 - Valve for Exhaust Flap 1 (N321)
P3019 00 [047] - Open Circuit
Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 2
Fault Frequency: 1
Mileage: 3879 km
Date: 2014.03.29
Time: 20:28:48

21399 - Valve for Exhaust Flap 2 (N322)
P3023 00 [039] - Open Circuit
Not Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 2
Fault Frequency: 1
Mileage: 3879 km
Date: 2014.03.29
Time: 20:33:30

No warning lights

Sounds quite loud on idle in front of the garage. I will do some testing tomorrow and see what someone else thinks. I will also check measuring blocks but the battery on my laptop was 2% so it died before I was able to
 
Ok I'm not convinced I can tell a difference. If anything, it might be quieter at higher RPM's. I guess the flaps would need to be disconnected when they are open e.g. >2500rpm otherwise they would simply stay closed?
 
veeeight said:
I think they are open by default when the car is switched off.
Click to expand...

I think you're right actually as I remember VCDS saying 'Open' when it was idling

Anyway I'll give it a blast tomorrow and see what I think

Need to tape up the connectors so they don't get dirty too
 
Good lad, waiting with bated breath!

Would probably be easy to see if the flap was open when car off too by inserting something flexible up the pipe maybe?
 
Itguy said:
Good lad, waiting with bated breath!

Would probably be easy to see if the flap was open when car off too by inserting something flexible up the pipe maybe?
Click to expand...

I'll let you insert something flexible up the exhaust haha :p
 
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Are you offering up your exhaust Scott ;)

Form an orderly queue :p
 
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Pulp84 said:
Think you might need to use a proper metal cleaner rather than worrying about adjusting the exhaust system.

My A1 185 has the same issue with carbon heavy deposits on the exhaust. Really annoyed me when I got it as my Mk5 GTI never did it. In the end I found this stuff the best Meguiars NXT Generation All Metal Polish - Clean Your Car.

Over time fine wire wool will take the lustre away from the pipes. Using this stuff seems to build up a bit of a resistance for deposits sticking.
Click to expand...

I've found a quick raid in the kitchen to get some of this stuff works a treat.

Cif | Stainless Steel

Use with very fine wire wool if/when stubborn blackness needs removing, then just wipe clean... Mrs isn't that impressed though ;-)

On the noise front.. it's a bit annoying that at 75-85mph in 6th the noise is at it's most annoying. Just the sort of motorway/autoroute cruising speed I like!
 
Well I've just been outside to see what I could test (don't have VCDS) and it seems like the valves are open when the car is off, and with the ignition on and with the car running at idle. I used a long flexible grabber that I've got in the garage and it certainly went in far enough to go past where the valve is located. Obviously couldn't test it at 3 or 4k rpm to see if the valve was open, shut etc. So maybe to only closes between off-idle and 2.5k??
 
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Lol.

Ok all looks good to me. Doesn't sound too loud/boomy. I haven't tested on the motorway but I've tested on some quiet A roads. 30mph in 4th sounds louder, but not too loud, and certainly not noticeable with the windows closed/music up :laugh:

Still no warning lights, just the faults logged on VCDS.

Easy enough to tape up the plugs/connectors with some electrical tape to protect them.

I'd recommend it.
 
I wonder if there is anything that could be monitored in VCDS while driving to see what the normal flap behaviour is in the different individual modes (comfort, auto and dynamic)??

Interesting that you can hear a difference. Is it a noticeable change over 'dynamic' when just pottering around then (windows shut)?
 
Itguy said:
I wonder if there is anything that could be monitored in VCDS while driving to see what the normal flap behaviour is in the different individual modes (comfort, auto and dynamic)??
Click to expand...

Yes.
Logging Measuring Blocks 245, 246 and 247 (plus RPM) in all the different Drive Modes will tell you at what RPM the flaps are open or shut.
 
Scott, another one for you mate as you have VCDS. I wonder if it is worth also recording throttle angle as the behaviour might be linked to that too??
 
I'd like to do this. Scott, so it's just case of getting under the car and unplugging the connectors? The valves stay open all the time then?

I have VCDS so happy to do some logging if it helps the cause.
 
That's what I understand. The flaps are electric obviously and are in a normally open state so I figure that as long as they are unplugged while open, they will stay open. A short burst of logging would be interesting just to know when the flaps usually are open / shut so we can tell where abouts we should hear a difference after unplugging / always open
 
It's very slightly noticeably louder with the windows closed but certainly nothing to write home about. It's a louder at slow speed/low rev driving and on acceleration from low rpm. It's a good improvement IMO. And yeh, just unplug the connectors on both sides and tape them up with some electrical tape to keep 'em clean :)
 
I'll do some logging, if no one else has, next week as I'm off to Spain tomorrow (last minute thing)
 
Ok, have unplugged mine tonight without having to jack up the car etc, the plugs are easily accessible. Taped them up and cable tied the out of the way.

Have a very quick run up and down the road and didn't really see any difference but it was such a short run, tomorrow morning will be the tell-tail run.

As another thought, does the dash noise generator always work in all driving modes or does that change too? I like to drive my commute in efficiency mode but want it loud!
 
Itguy said:
Ok, have unplugged mine tonight without having to jack up the car etc, the plugs are easily accessible. Taped them up and cable tied the out of the way.

Have a very quick run up and down the road and didn't really see any difference but it was such a short run, tomorrow morning will be the tell-tail run.

As another thought, does the dash noise generator always work in all driving modes or does that change too? I like to drive my commute in efficiency mode but want it loud!
Click to expand...

The dash noise generator will open only on dynamic or set manually via individual.
Cant set efficiency and get sound :busted_cop:
 
Itguy said:
Ok, have unplugged mine tonight without having to jack up the car etc, the plugs are easily accessible. Taped them up and cable tied the out of the way.

Have a very quick run up and down the road and didn't really see any difference but it was such a short run, tomorrow morning will be the tell-tail run.

As another thought, does the dash noise generator always work in all driving modes or does that change too? I like to drive my commute in efficiency mode but want it loud!
Click to expand...

The only time you really notice (IMO) is when the engine is warm and slow speed stuff, pulling off, accelerating from low revs in high gears, it just gives a bit more sound. It's not noticeable at all really, but if you listen with the window down, it definitely makes a difference outside
 
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audi upgrades
I just did this mod today, definitely a slight difference in noise - more boom, think the car should have come stock like this IMHO. Have the rest of you left it unplugged or have you returned it back to stock?
 
Mines been unplugged for a week now. Makes all 4 exhausts equally dirty now and actually much easier to clean as the soot concentration is now over 4 pipes rather than 2.

I'm loving the sound and as I typically stick mine in Eco mode for my commute
 
audi upgrades
Itguy said:
Mines been unplugged for a week now. Makes all 4 exhausts equally dirty now and actually much easier to clean as the soot concentration is now over 4 pipes rather than 2.

I'm loving the sound and as I typically stick mine in Eco mode for my commute
Click to expand...

That's good! Always find it a pain having to clean the inner pipes if I don't wash it for more than a week
 
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