# E39 M5 DSC Performance



## Islip335 (May 4, 2004)

Changed 3 months ago from an E34 540 to a 1999 E39 M5 and find the
traction control incredibly intrusive. On the 540 it came in very
progressively, but allowed maximum performance.

In the M5 even quite moderate acceleration at any speed can produce
severe 'braking' from the DSC - it makes overtaking potentially
dangerous as you don't know what the DSC might decide to do.

I have turned it off in the dry and on the same road at the same
speed there seems to be plenty of grip, so why does the DSC cut in so
violently?

What are others experiences and is there a software upgrade from BMW
to improve it?


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## rost12 (Dec 22, 2001)

I usually turn it off in the dry, so yeah, I too find it overly intrusive. AFAIK, no software updates were ever issued to correct it, and BMW DSC's intrusive nature has been noted by most car mag. reviewers as well.

Just do the two button salute when you get into the car!  (DSC off & sport mode on)


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## 528i (May 1, 2004)

The UK got an e39 M5 in 99? I guess I must do some homework


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## DZeckhausen (Mar 11, 2003)

IslipM5 said:


> Changed 3 months ago from an E34 540 to a 1999 E39 M5 and find the
> traction control incredibly intrusive. On the 540 it came in very
> progressively, but allowed maximum performance.
> 
> ...


What tires are you running?

I have the M5 limited slip differential in my E39 540i and found that it dramatically reduced the interference from DSC. However, when I install winter tires, the DSC again rears its ugly head, cutting power and applying brakes to kill my forward momentum. The wheel speed sensors detect the tread flex of my winter tires and think they are about to lose traction. The DSC tries to preempt that "traction loss" by cutting power. It's not as bad as it was before the limited slip installation, but it's still pretty significant.

Could it be that you are using low performance tires? Have you tried a set of Michelin Pilot Sport 2 or Goodyear Eagle F1 GSD3 tires to see if the problem is reduced or eliminated?


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## Islip335 (May 4, 2004)

I had thought about tyres as well - I ran Michelin Pilot Sport on the 540 and found them excellent. The M5 has Dunlop SP Sport 9000 on the rear, which will be replaced with Michelins in a few month's time. Be interesting to see if there is a diffference.

Thanks for the suggestion.

Richard


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## mottati (Apr 15, 2003)

IslipM5 said:


> I had thought about tyres as well - I ran Michelin Pilot Sport on the 540 and found them excellent. The M5 has Dunlop SP Sport 9000 on the rear, which will be replaced with Michelins in a few month's time. Be interesting to see if there is a diffference.
> 
> Thanks for the suggestion.
> 
> Richard


When I did the "M5 driving experience" about a year ago, one thing i remember is how much better grip the car's on michellin pilot sports had vs the cars on dunlops. I have pilot sports on my 00 M5, and even so, the DSC is intrusive. As mentioned above, before i drive off, i usually press the dsc off and the sport on.
Mike


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