Sixty1

I have seen otherposts on the dual mass flywheels. Has anyone run a lighter and/or single mass flywheel and what pros/cons have you noticed?
I have a 2004 S4 B6 which I love in the high gears, but the lack of return to idle, impairs the lowend fun factor. I know this mill has great compression, but the clutch feel is inconsistent. Thoughts....

DrGP

How much of this problem might be attributed to the DBW program?

Sixty1

I guess some of it could be that, but it is when I come off the throttle, the revs come down slow. The potentiometer should be progressive both ways, but since I do not know the algorithm for this I can't say. I do know, when you rev it up, it comes down slow in comparison to other performance vehicles I have driven. I would much rather flash the program than change a flywheel

Sia Bani

Wouldn't something mechanical like the flywheel be consistent in up-rev and down? I don't see why it would be slower to rev back down because of a flywheel.

Now for the stuff i do know...

The reason why our cars rev back down slowly is for emissions apparently. You can search the archives to read more about emissions, dbw, and the revs being controlled as such to limit the smog dump as someone put it on here...

bhvrdr

you'll get gear chatter and mild vibration at idle and in any gear under 3000rpm. Car will sound a bit like a diesel Mercedes. Accereation was not improved and clutch is harder to modulate off idle but rev-matching and throttle control is otherwise improved. The cons are dramatic. The benefits...not as dramatic.

ESFO

Some good reading:
https://forums.audiworld.com/s4b6/msgs/121379.phtml
https://forums.audiworld.com/s4b6/msgs/121512.phtml
https://forums.audiworld.com/s4b6/msgs/121694.phtml
https://forums.audiworld.com/s4b6/msgs/122185.phtml
http://est.org/S4b6throttle/index.html

bhvrdr

and revmatching is a delight but otherwise they are noisy as all hell and vibrate. The stock DMFW is very very heavy and is the cause of much of the slowness in throttle response (DBW responsible for its own share). A lighter DM unit would be something i'd love to find.

bhvrdr

It will cause funny things like a lack of response when blipping the throttle, and hesitation off the line but the slow return to idle is likely the heavy *** DMFW we have. When using a 12lb SM unit mine dropped incredibly fast as soon as the clutch was engaged. Blipping and rev matching was much more responsive and better controllable.

Sixty1

So I could see how the CPU could dictate behavior of these kind of engine parameters for smog and other factors. Are there any aftermarket progams that not only give you more power but improve throttle response?
As for the flywheel... spinning the motor up you are putting energy into the flywheel by combustion. When you lift your foot off the accelerator on a simple motor (in neutral), a light fly wheel will return to idel faster than a heavy fly wheel (more mass=more intertia) with all things else remainning the same. So I read that audi's run dual mass flywheels, which makes sense to this behavior. It is helpful to know that the electronic may contribute to the characteristic as well. I would like to improve throttle response in general. Any ideas on how to do that?
Thanks for the feed back... keep it comming.

Sixty1

Re: are there different grades of LWSMFW's? Happy medium?