My M5 debuts @ a track event this weekend: suggested tire pressures? - The Unofficial BMW M5 Messageboard (m5board.com)

masmole · 29th March 2006, 08:38

I'm thinking of going +3 psi above door jamb suggested numbers on all corners to start with.... then using some tire chalk, I can monitor sidewall roll (especially the front tires) and vary pressures accordingly. I don't have a device to measure comparative tire temps so I'm leaving it to tire chalk and how the car behaves. Other than that, any suggestions from those who have tracked their M5's on what cold tire pressures to start with?

This oughta be good wholesome fun tearing-up (literally) the stock Contis at the track. I'm also anxious as to how the stock brakes will hold up at this 3-day lapping event (3.5 mile circuit). Ideally, I'd be much more comfortable with a set of Hawk pads or something more track-worthy than the stock pads but alas they're not available in the M5's fitments yet. Also, a set of Pirelli Corsas would've been nice as well but too late to fuss about that now since the event starts on Friday.

I have also installed a camera mount and will be taking some in-car vids as I maneuver this great road course. I will of course edit the footage and post only my best laps with the best racing lines taken here on M5board so that none of you will notice my (lack of) mad race driving skills

Most of all, I'm just very excited to see how this heavy luxury car will fare in trying to impersonate a race car. I'm fairly optimistic with the results despite knowing full well how the laws of physics apply to a 4100 lb piece of machinery at speed.

NobleM400 · 29th March 2006, 09:10

Even without a pyrometer, you can use your hand to just feel the tires. That'll give you at least a rough estimate. It's not perfect, but works ok.

Did you get an alignment yet?

DrKevM5 · 29th March 2006, 13:15

I usually start 5lbs. above recommendations, then adjust accordingly. Good luck!

SCORPIO · 29th March 2006, 16:25

I used +5lbs for my tracking last weekend - seemed to work well, I was quite surprised at how well the Contis held up and how sticky they get!

Brake fade will be an issue for you - just remember, it is a big, heavy understeering car...have fun!!

6speed · 29th March 2006, 16:40

Are you going to Road America? If so, that place is phenominal.

Cheers ///

SGM5 · 29th March 2006, 20:56

Right--let us know how it goes. I'm taking mine to Mid-Ohio the following weekend for a club drivers school, so I'm interested in what tire pressures work for you, if you end up staggering the pressures, how the tires hold up, and especially how the brakes hold up.

Mid-Ohio is not as hard on brakes as Road America (if that's where you're going), but this is a fast, heavy car on stock pads, so I'm real curious as to how it will hold up. You're able to get some real speed up in the longer straights at Road America, and hauling it down lap after lap will really test the brakes. I've used competition pads on my E46 M3 and had no issues, but I've seen E39 M5s on stock pads go through them in a day at Road America.

By the way, a friend who's a pretty good driver--B run group--in an E46 M3 said a guy in an E60 M5 ran away from him a couple of weeks ago at VIR. Maybe it was somebody on this board. So you should have a good time.

qpilot · 29th March 2006, 23:10

I did an autocross about 2 weeks ago and ran 40 front and 42 back. Stock tires held up quite well after 6 runs. Understeer is an understatement. BTW, I never even bothered with P500 and my car was 1000+lbs heavier than all the other cars there!
It was fun though - see attached

qpilot · 29th March 2006, 23:11

And no - I didn't get any of those cones :-)

DrKevM5 · 29th March 2006, 23:15

Autocross pressures will differ greatly from track pressures.

petesamprs · 30th March 2006, 00:12

NobleM400 · 30th March 2006, 01:24

Quote:

Originally Posted by petesamprs

How?

You'll generally experience lower temperatures for autox.