Traction problems at high speed?

Hi Holger!

I know it's an old thread but I've read it just now. Sometimes I feel the same like you but not just in the M5 but in other cars too /but not always / Some months before I could try an Impreza WRX STi with full of WRC components, there wasn't any free space under the engine hood: two intercoolers, turbo chargers, etc... everything what you can imagine Like a real rally car. So, I just want to tell you the run ->awesome We run more than 220 kmh in the city oohhh:
The car was all wheel drive of course and hold the road well but still that run was frightful, indeed!
So, I think you should choose a safe road or stage watchfully and your problem will play second fiddle, the first thing what will come to your mind will be the run and the pleasure:flag: It is possible that I am wrong but I think this If the conditions are perfect you will not hark to the mentioned question, perhaps.
On the other hand, if we look the M5s in general terms they don't meet with accidents, according my infos :3:
I think it is needless to install a bigger rear spoiler, but it is depends on you

Have a lot of great runs!
Best,
:flag:

Holger said:

My M5 runs real 185mph and starting at approx. 150mph the traction really sucks. It feels that the rear wheels haven't enough ground contact anymore and the suspension seems not to be made for this speed. Has anybody equal problems and exists there any kind of flaps or small spoilers to reduce this phenomen?

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I think it's extremely unlikely many people who are members of this board will even have hit the 155 mph limiter. The few people who have hit the limiter or gone above it almost certainly did it on a track or on the Autobahn.

The simple reason being that 185 mph would be highly illegal (instant ban / large fine / jail) in most countries.

It is possible that at very high speed, your tyres are centrifuging outwards in the centres, and reducing your traction, and it's also possible that you are lacking sufficient downforce on the rear end. Certainly it is possible that BMW would recommend different tyres for speeds over 155 mph, and they may well have envisioned different ride height and suspension geometry in their high speed tests. Designing a car to do 155 mph is a heck of a lot easier than designing one to do 185 mph (power required to overcome wind resistance varies as the cube of the speed, for example).

You would not get me driving at 185 mph in my car anywhere anytime. At that sort of speed, a tyre blowout (because of a nail, or whatever) would have fatal results.