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Discussion Starter #1
Had a blast today running the M5 in a local SCCA Solo II event (autocross). The M5 did alright, it beat most of the stockers there (couldn't beat my buddy with a 528 grrrrrrr . I was amused that they classify the E39 M5 as "Super Stock". So anyway, I was the only one in that class, got the trophy (by default), and got to run in the #1 spot to boot.

After the race (5 hot laps) I was inspecting the tires, and noticed the scrub marks on the front tires, and couldn't believe how far the tire was folding under. I was running 40 psi at all four corners. Is this normal? Wow.

:M5launch: -Bill




 

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:eek:

WOW Bill! I have never seen that much rollover, but then again, I only track and haven't done autocross.

When tracking, I am about 1/4" above the dots on the sidewall.

I did hit a berm on the track cutting through the esses once that split my passenger side front tire, but haven't seen rollover like that.

You musta been drivin' it like you stole it! :byee55amg
 

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Holy cow, that's way more rollover than you should see. It's a good thing you were only autocrossing, that much rollover on the track could have destroyed your tire. I don't track my M5 so I don't know what tire pressures to expect, on my M3 with R-compunds I start at about 28PSI cold and expect 35-36PSI when they are at track temps. Obviously if you are starting at 40PSI (I am assuming cold) then that isn't enough for autocross use at whatever ambient temperatures you saw yesterday. You should see the tire roll over to use all of the tread down to where the outside tread blocks end, but never scrub the tire onto the sidewall.

Regards
 

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Yowsa. That's a lot. It looks like you're running stock front wheels and 245 tires, yes? Maybe go to a set of rears on front? Are you running camber plates?
 

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Bill,

In years past I've done a ton of autocrossing, and my take is a bit different than above. If you notice, the "real" rollover was not that crazy...real meaning where the majority of the wear occurred. I've seen this exact type of thing in the past, and it is usually a result of bumps on the course during extreme cornering. This does not look like continuous rollover to me...more of a transient spike.

That said, camber plates will go a long way to making the front work like it should in an autocross. ;)
 

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Bill,
Congratulations on your big win!!! :7: :7: :7: You sound like me when I did those autox's with the local club last yr and the yr before--my BMW's would be like the only one's in the class-- ussually an easy win :biggrin: Seriously though, glad to see you taking your M5 on the track. The more I drive my M Coupe on the track and try to go back to the M5 even on the street, the more I realize what a potent, "manly" handful it can really be---shhhh, don't tell anyone I just admitted that.

Now to business. Not that I've done that many autox's and only two with my M5 in high speed autox events (2 mile road course), but I think CSBM5 may be on the right track (ha ha) with his analysis of your tire wear. You may just be scrapping them up, rather then rolling them over (?) Those are street tires, right? What was the course like? Was the surface flat or banked anywhere? Where was it set up? Did you do the chalk marking bit on your tires? Did you just do one 5 lap event on the course? OK enough with the questions!!!!!

Anita
 

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Discussion Starter #7
I think the surface had something to do with it. It was recently resurfaced, and it was very "course". I don't know what they did, but it was anything but smooth. Almost like a car painted with a broom - it was completely rough. And it got loose at the surface. One of the old-timers there said it was like racing on ball bearings. I thought it was more like a gravel or dirt track in the highly worn areas. Just a wierd parking lot, but maybe that's why the tires were scuffed up so high.

Anita: I remember you mentioning some first place finishes similar to this one!

:byebye:
 

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ELEVENS said:
I think the surface had something to do with it. It was recently resurfaced, and it was very "course". I don't know what they did, but it was anything but smooth. Almost like a car painted with a broom - it was completely rough. And it got loose at the surface. One of the old-timers there said it was like racing on ball bearings. I thought it was more like a gravel or dirt track in the highly worn areas. Just a wierd parking lot, but maybe that's why the tires were scuffed up so high.

Anita: I remember you mentioning some first place finishes similar to this one!

:byebye:
Did you get any feedback from the others that ran on that course, like your buddy with the 528i?
 

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Wow, thats some heavy cornering! The pic proves that you had fun!:biggrin:
 

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I use to do that to the tires of my 528 quite a bit, but that car also had 90 series sidewalls. ouich If it was a rough venue, the bumps can compress the sidewalls during hard cornering, and sometimes it will make contact with the road. At least it shows you were trying!
:thumbsup: to your buddy in the 528! I remember the good old days of picking on M5's through my favorite offramps with my 528. He does have a good advantage over you in the slow speed stuff with the all aluminium suspension. It would be better for him to get rid of his 90 series sidewalls too... :biggrin:
:cheers:
 
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