On Wed, 25 Apr 2001, Mike Eynon wrote:
> This last weekend I lost my autoX virginity down in Marina. I gotta say I
> was a little leery about letting anyone co-drive my car, but, I am now a
> believer. I learned more from Kevin Stevens than I ever thought possible.
> Plus, for someone who has not driven an M3 for quite a while, I was pretty
> darn impressed. He did things in that car that I did not think were
> possible, and he was as smooth as silk doing it. I have not seen the
> results yet, but I am pretty sure Kevin drove the winning lap in the AS
> class (Didn't stick around for the final results). Not bad considering we
> were running street tires.
I blame this entirely on Navid Kahangi. He keeps saying that M3s are SS
cars, and I guess it just sunk in. Come to think of it, maybe he wasn't
talking about the '98 model; but hey, all those foreign sedans look alike!
Actually I've never driven an M3 in a timed run before - had a couple in
the SCCA school three years ago, and I'd taken one fun run in Jim Ochi's
car. I was very impressed at how responsive and easy to drive your car
was. The only thing I did that I didn't think was possible was to fit in the
driver's seat without breaking my neck!
Note to the list - Mike isn't saying, but he did pretty darn well himself
for his first event! We'll have to see the results, but I know he beat my
first run a couple of times...
> Thanks Kevin... thanks a ton. You can co-drive my car anytime.
Back atcha.
> I have a couple of rookie observations and questions. First, I discovered
> (thanks to Kevin) that the most important part of the day was probably
> walking the course. I got huge amounts of information that was invaluable
> behind the wheel. Unfortunately Kevin will be away next weekend (May 6)
> when I plan to race Marina again. Can I get someone who is planning to go
> to walk the course with me? I think a couple more assisted walks and I will
> be proficient.
One thing we picked up from the course walk was the different lines that
were available. This particular Marina course was VERY wide, and there
were several turns that had looked quite tight - possible first gear -
while watching the earlier run groups. Upon walking the course, it was
clear that people had just been making problems for themselves, and by
taking wider lines we could run second gear throughout with no problem.
Also, in many cases, the wide line was clean enough to use, which isn't
always true. Marina is rapidly becoming my favorite site, it has cleaned
up very similarly to the McClellan concrete site in that regard.
Another note: while you usually have to go where the line is clean, don't
necessarily follow the black skid marks (especially the ones that make
really tight circles!). We saw many cases where the tire marks were from
people overshooting the turns.
> Also... when I got home I almost cried. I just went out and spent ~$1200 on
> 4 max performance tires that were nearly shredded on the outside edges (that
> was with bumping the pressure way up). My mechanic buddy said that if I
> continued to run on these tires, I could expect to run 3-4 more races before
> having to get new tires. He, along with many others, has suggested that I
> invest in a separate set of wheels with racing tires. Sounds like a plan to
> me, but I need a little advice.
First of all, don't worry about the current tires. We didn't do anything
that will shorten their normal road life expectancy; autox is just hard on
the shoulders with your car. It's kind of the reverse for driving autox
tires on the highway - all the wear is in the center, which isn't usually
where THEY wear out! Copacetic.
Second, remember when I said that I had an order on a M roadster but
decided to get a Corvette instead? One reason is that the BMWs have very
little camber adjustment available, so it's impossible (in Stock) to get
enough negative camber to make the tread surface flat during hard
cornering. By comparison, my C5 Corvette could easily get 2 degrees of
negative camber per wheel in the front (though it didn't need quite that
much).
Third, working on that "turn the wheel out" on corner exit will help quite
a bit with tire wear. One thing I forgot to mention was that, relatively
speaking, when you were driving we heard more screeching from the front of
the car (some of that was the passenger, though!), and when I was driving
we heard more screeching from the rear of the car. In the big back
sweeper/straight I was getting more rotation done early and getting the
front wheels straighter earlier.
> There seem to be 4 main types of Hoosier racing tires: Road Racing, Road
> Racing Wets, Sports Car DOT Bias, and Sports Car DOT Radial. What are the
> differences, and what should I be running. As well, should I also run all
> four the same size, or keep them staggered like stock. Being that I have a
> moderate amount of under steer with the stock setup, I would be more
> inclined to go with the same size all around.
Sports Car DOT Radial, autocross compound. Actually, for your car I'd
recommend looking at the Kumho tire, for several reasons:
a) They're cheaper!
b) They last somewhat longer!
c) One of the things your car does very well is to provide feedback, and
respond very linearly and precisely. Hoosiers tend to drive a bit
"looser", and I think you'd be giving up some precision with them that
is quite valuable, especially at this stage.
As for size, the first consideration would be whether with same-size tires
you could swap wheels front-to-back to even the wear. Unfortunately, your
car I believe has different width rims front and back, so that's out.
I didn't feel that your car had a understeer problem, but front tire grip
is usually the ultimate limiting factor in cornering with that type car,
so bigger is usually better.
Jim, Rex, Navid - anybody have Beemer setup tips for Mike?
KeS
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