I have been thinking... S4 1/4 Times...

[shineydave]

the warning light comes on. round orange light with a triangle in the middle

[smurfbus]

I did not watch my inst. cluster but I can feel it using the brakes sometimes, it kills the accel when its bad. So by disconnecting the ABS-harness you can temporarily disable ABS and EDL, but remember to reconnect it when you go back to road. There are nice diagrams how to do it with a diode, but I'm too lazy for that + I only need it maybe twice a year.

[GrahamS4]

Sorry for going OT. I'll start a new thread if I need to know more. I thought EDL was something fitted to all S4s, not just post FL with ASR or ESP.

However I've span a front wheel turning into corners and never seen light come on of felt the power reigned in, so I guess I was wrong. Simple old Quattro for me it seems!

[smurfbus]

<OT there is a speedlimit that deactivates EDL maybe 40kmph? I dont remember seeing the light either. MY99/2. All S4s have EDL as there is no mechanical differential. Stasis has a nice LSD but $$$.

End OT>

[KayGee]

Don't get a warning light with pre facelifts. US guys use switch and a diode. Search AW for EDL defeat. Seen claims of .2 improvements. Suspect that is on crappy 1/4 strips. Never had a problem at Santa Pod.

[ZeroK66]

Interesting, did not know this. I assume on a facelift disabling ESP would also kill diff lock? Diff lock surely be a good thing for launches?

[GrahamS4]

I wash brushing up on this from what I could find on the Audi site. Generically, Audis that have ASR, still have EDL and likewise cars with ESP have ASR and EDL! Disabling (button) ASR kills ASR EDL still active, disabling ESP (button) kills ASR, EDL still active.

It now makes sense all S4s have EDL (Quattro IV). I'm sure it's in my manual. Believe on S4s and other performance models the system is good up to 80Km/h instead of 40. I can't help that think EDL must be good for launching. OK a diff that locked properly is what you really want, but anything, even an electronic system that brakes the spinning wheel has to be better than a totally open diff.

I have to say EDL either only steps in really late or it's very unobtrusive (does not cut engine power, that's ASR) as like I say I have many a time tucked into a sharp turn and had the inside front pick up and spin and never noticed a traction aid cut in.

[ZeroK66]

Ahh, EDL works by braking the wheel... Mmm... right. Well in that case it cant be good for launches.

I have never noticed the car being held back and I do some agressive launches from time to time, but interesting to know.

[GrahamS4]

Ahh, EDL works by braking the wheel... Mmm... right. Well in that case it cant be good for launches.

I have never noticed the car being held back and I do some agressive launches from time to time, but interesting to know.

But it's the reason it brakes the wheel!!

It brakes the wheel that's spinning, to force the power back to the other wheel on the axel, imittating what a limited slip diff would do, to a limited (no pun) extent.

If EDL didn't brake the wheel, it would just spin and power would NOT be transferred to the wheel which is not spinning.

As this is done without cutting power or revs, unlike traction control systems, I think this is good.

Unless people have fitted mechanical LSDs, I don't see how defeating EDL can help with better times.

There's yarns of this type of discussion on the AW forums.

Then you get into the what if one wheel is off the ground theories.......