Hey Dr. Bob,
We talked about that on the phone once, and I will admit it
totally slipped my mind, or I didn't register it as
significant enough. But it's a wonderful metric.
I could see this right at home on our Statistics dialog, on
the Summary page. That dialog is already rather large, but
hey, in for a penny in for a pound. Look for it on a coming
version. We'll be sure to give you credit in the Help
pages, too. THANKS DOC!
--Byron
"Dr. Bob Woods" wrote:
> I would like to share with you another number that we have found by
> plotting the average g's (average of the g-vector from the start to the
> finish of an autocross). The correlation is quite good and shows that an
> increase in 0.1 g's average results in 3.0 seconds on a 60-second course.
> This 0.1 g's can come from driver ability or from the tires. Further,
> tires drop by 0.1 to 0.2 g's as they wear from new to about 25% of the wear
> indicators left (I'm referring to racing slicks on a Formula SAE car).
>
> We use this average g's as a metric for evaluating our driving. This might
> be something that Byron might want to include in his metrics. Incidently,
> at SCCA nationals, we have recorded over 1.1 average g's (with no aero).
>
> Dr. Bob Woods
> Faculty Advisor, University of Texas at Arlington Formula SAE
> Amod driver
>
> At 12:25 PM 5/6/00 -0400, you wrote:
> >GH Sharp responded:
> >
> >>In a message dated 5/5/00 3:45:14 PM Eastern Daylight Time, Todd wrote:
> >>
> >>> I've specifically been focusing on being agressive this year and GEEZ
> >>> seems to reflect this, but I'm beginning to think I've reached the limit
> >>> on how far just raw pushing it can take me.
> >>>
> >>> My theory is that aggressiveness will take you to a certain level at
> >>> which you'll plateau. Only by being smoother can you keep the car
> >>> settled and put the power down (in a relatively high horsepower RWD
> >>> car) and ultimately generate more grip for better times.
> >>
> >>There is some truth to that, but more cornering grip and bigger lateral
> >>"numbers", regardless of how you obtain them, *may* not be the answer
> >>to a faster time. Bob is likely taking a better *line* than you are in
> >some
> >>places, and getting through certain parts of the course quicker than you
> >>even though you're pulling higher "numbers" in those areas. An example
> >>would be a slalom in which one driver pulls the maximum lateral g's that
> >>the car can generate around every cone, when another driver might be
> >>able to negotiate that slalom by running a tighter (and shorter) line
> >through
> >>the cones which might not necessarily generate the same peak lateral g's.
> >>
> >>> Thus my corollary is that even though I'm being scored at 99%, that
> >>> rating is based on the peak and sustained values I can generate. If you
> >>> were to put Bob in my car, his G's would be even higher and thus my
> >>> ratings would go down in comparison.
> >>
> >>If I understand how Geez figures this (Byron or someone correct me if I'm
> >>wrong), the usage numbers are based on how closely the driver comes to
> >>the peak numbers seen when he drives the car. Therefore lower "peaks"
> >>by another driver can actually generate usage percentages similar to those
> >>of the first driver, as long as the second driver stays equally close to
> >his
> >>lower
> >>"peak". (I'm not sure I even understood that explanation myself <g>).
> >>
> >>OK, a friendly wager: I'd bet that if Bob and you had both driven your car
> >at
> >>Lemoore, Geez would likely have shown your peak numbers as being *higher*
> >>in some places on the course than his, but he actually may have negotiated
> >>those portions of the course as quickly, or more so, than you. He may have
> >>used a line which was straighter in some places than yours, loading the car
> >>less (and generating lower Geez numbers) but letting the car use its power
> >>to push the car forward, instead of against the cornering loads of the
> >tires.
> >>Another consideration: that straighter line may also be shorter, so he
> >drove
> >>less distance to get through the course.
> >
> >I concur with this. When I started autocrossing in the late 80s I bought a
> >g*Analyst and I worked at generating the greatest Gs at every possible
> >opportunity. It wasn't until I compared my runs with fellow C/D stocker Jeff
> >Perkins that I discovered he ran about the same lap times (or in some cases
> >better), but I consistently generated more Gs than he did. Now, mind you I
> >was driving a Porsche 944 at the time and he was driving an MR2 so you could
> >say the difference was the car. But when I compared myself to Noel, his
> >wife, I found that my lap time was slightly faster, but she drove the car
> >much more like I did.
> >
> >What you really need to do is compare your runs to a variety of other
> >drivers and see how their style and line may be better or worse than yours
> >on that particular day. It would be incredible if we could get hundreds of
> >drivers on the same course under the same conditions so we could compare
> >various approaches. Topeka '00???
> >
> >Paul Foster
> >
> >
> >
> >
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