Managing exhaust valves on Audi RS4 B7

[KIQUE]

Hello,

Sorry for my english ...
Does anybody know how to modify the software for exhaust valves ?
As you know even in sport mode "S" valves are closing at a particular range (I would say 2500 to 4500 ?) and also close when your foot is not on the throttle (when decelerating).

To make it simple, I would like to have them 100% open in sport mode.
(Unpluging the valves pipe is not a solution for me as I still need to calm down the exhaust on demand).

Thanks for your answer !

[harding]

The valves are not controlled by a software, it is fed by vacuum lines which opens the valves after 3800rpm on the 1,2,3d gear. In 4,5,6 the valves are open all the time. I would love to have the valves as you requested but i dont think its possible..

Oh, and the valves are open under 1000rpm aswell (i usually let the secondary air injector stop and hear the flaps open before i drive away, takes a minute or so)

[KIQUE]

Thanks for your answer.
I heard that RS Quattro in Belgium was able to modify the valve management ... But how ? Unfortunately it's too far from my place.

[MikeFish]

I don't think it is that much quieter in non-sport mode. Have you tried disconnecting the valves first to see if you can live with it like that. I think it is still quite quiet.
It must be worth just pulling them off for a day or 2 to see how noisy it is.

[KIQUE]

Yes I disconnected the pipes "manually".
It's much much better and louder on 1,2 and 3rd gear.
But I still I need to calm down the exhaust with the "S" mode on the steering wheel

[rwilsonrs4]

when you disconnected the pipes did you block the lines with a piece of vac pipe and a screw ? if you didnt it will cause vaccuum issues with the engine

[Paul-RS]

If the RS4 exhaust flaps are controlled via vacuum via solenoid valves, then there are loads of switchable versions of the
"Flapper mod" on the web.

Some cars have a vacuum / ECU operated "flap" in the exhaust tail pipe.
It is opened and closed at certain pre determined revs, speeds, gears , mostly to control noise etc. some cars like TTRS and also RS3 have a sport button that can influence the flap more, but still certain revs, speeds gears. When open on the RS there is a noticeable tone or volume difference, so much so, I think the second tail might take a less restrictive route through the back box internally.

Flapper mods vary from removing the pipe and sealing off, so 100% open to switchable on off, or standard,loud, quiet to fancy remote control, or extra vacuum valves that retain oem system, and provide an override Off function.

It was a real popular mod on R32's and has grown since.

I'm standard, with the factory sports button, and 100% on would do my head in, there are times where you just don't want the drone, like on motorways etc. This is where a switchable option comes in. There are loads and loads of different variants if you google switchable flapper mod.

I've looked into it, even found a relay board that I could be controlled with a iPhone. ( a first and a twist on the remote version , that I haven't seen before) it would be stealthy, and avoid drilling holes for a switch, but not so practical when driving!

For now, I'm standard, and I creak and rattle free, and like it that way, even if I could make it plug and play, I'm not sure I would want to pull my car apart to install it

The first link is very good, but only in German. ( it does mention some tuners can map the flaps on the RS3)

And the other links are just a few other ways it's been done before on various cars, but not RS4 specific. They might point you in the right direction for your cars.

http://www.luetz-hawranke.ch/Audirs3/Do ... uerung.pdf
( German to English pdf translation has so far eluded m, you can translate chunks with Google )

http://rdefined.com/phpbb/viewtopic.php?t=1651

http://forums.vwvortex.com/showthread.p ... mod-How-To

http://www.billswebspace.com/ExhaustSwi ... hrough.pdf

http://www.ttforum.co.uk/forum/viewtopi ... 9&t=333378

Hope this helps, happy reading.

Paul.

[KIQUE]

Thanks a lot for your answer.
If I understand your links, the solution is to place one more switch.
But I'm looking a way to remap the ECU controlling the valves.
Is it possible with Vag Com for example ?

[MikeFish]

Thanks a lot for your answer.
If I understand your links, the solution is to place one more switch.
But I'm looking a way to remap the ECU controlling the valves.
Is it possible with VAG COM for example ?

It's not possible with VCDS as far as I know. If you want to control it via ECU then you need to speak to the remappers. Douig from MRC will be able to tell you if this is possible.

I still can't believe you think it is too loud in sport mode with the standard exhaust. I have gutted pre-cats and disconnected valves and still think the exhaust is near silent. My air filter makes more noise.

[KIQUE]

Hi

I just fitted a scorpion exhaust
With standard exhaust my valves were disconnected like you did

[MikeFish]

Hi

I just fitted a scorpion exhaust
With standard exhaust my valves were disconnected like you did

Ah, ok now I see!!!

If you really want to do it via the sport button speak to Doug or your local / preferred remapper to see if it is possible.
Or you could look at installing a seperate sport buttion on the dashboard (like the cars with multifunction steering wheels have) and wire it to the vacuum reservoir that controls the exhaust valves so you have individiual switch not reliant upon the ECU.

[KIQUE]

Yes.
My local remapper does not know how to modify at the moment ...
I could ask MRC but as I won't meet them for this modification (too far in UK) I don't think they will answer me or answer my remapper

[rob-s]

I am not sure if a short answer have been given but simply it works so that you disconnect the vacuum tubes at rear at both sides, stuck them and put them back.

It is important that they are stuck and not left leaking. This is a very simple and worthwhile modification:)

[MikeFish]

Yes.
My local remapper does not know how to modify at the moment ...
I could ask MRC but as I won't meet them for this modification (too far in UK) I don't think they will answer me or answer my remapper

MRC might be too far but they should be able to tell you if it is possible or not.

[adsgreen]

I asked Doug at mrc about three years ago and he asked melinha on Skype and iirc it's not possible with the ecu mapping.
Easy to fabricate separate switch