Mosport on RA1

["Christian Sorensen" <sorensen@xxxxxxxxxxx>]

Well, I survived three full days of track running at Mosport this past
weekend, but my brand-new KFP pads didn't. I believe I have my Toyo RA-1
rubber to thank for this, as the greater stick allowed greater speeds which
necessitated (and allowed) greater braking. Over the course of 13 20-30
minute runs my front pads sacrificed themselves against the rotors, their
carcasses presumably vaporized into the southern Ontario winds.

It sure was fun! Even on 15-inch rims, the track rubber allowed dramatically
better grip than I'd ever experienced with street rubber.  Over the course
of the weekend as my lines became smoother and more consistent I was able
appreciate the difference on every single corner.  The most fun (and
breath-taking) was corner two, where I was able to power-slide down the hill
through the second apex.

Coming up the back straight hill I was consistently able to top an indicated
200km/h, which also made me marvel since I'd only ever seen 180km/h
previously.  Perhaps Bavarian Auto had performed some gratis engine mods
when they installed the pads and the cross-brace?  Then it dawned on me that
205-50x15 tires have significantly less circumference than my regular
225-50x16s, enough so that an indicated 200km/h amounts to 185km/h
calculated proportionally. One does perform the calculation as a proportion
of overall diameter, right?

I set my tire pressures at 34psi on the fronts and 31 on the rears, and used
these consistently throughout the weekend. I observed 'just the right'
amount of wear front and back according to my instructor.  Wear they did
indeed, as they certainly don't look new any more! I estimate that about
half of the tread depth is gone, which means I'm not going to be tempted to
use them in wet conditions. I believe that as long as the rubber is soft
they're still going to be good to use, but how will I tell the difference?
How do you tell when track tires are gone if they're not obviously corded?

Another problem with the tires cropped up during the weekend and that was
picking up a screw on Friday. Since I was changing back to the streets every
evening to go back home to Toronto I noticed it and had the thing plugged.
After that I switched it to rear-duty: it betrayed no noticable loss of
pressure for the rest of the weekend.

The only bummer of the weekend was getting hauled over by the OPP on Sunday
morning on the way to the track.  For this I naturally blame my partner in
crime, John Fulford-Brown, who was running with me in his fancy new blue M
Roadster.  Actually I do accept responsibility for this, its just a pain to
be nailed when cruising (literally) at 142km/h along a long, dead-straight,
stretch of 3-lane highway.  The laser unit was hidden over the crest of a
slight hill on the stretch of 401 just before Bowmanville: I'd seen the
cop's parked car and eased back on the throttle but not in time.  Just my
luck that John was following instead of leading then :(

All-in-all it was a very memorable time and marked my graduation into
serious track-junkiehood.  Now I've even changed pads myself at the track!
The June school is only 6 weekends away and I'm already plotting for it.


Christian Sorensen
VP-Data Recovery Labs
BMW 328i almost stock
BMWCC, BMWCCA

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End of bmw-digest V9 #1075
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