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Discussion Starter · #1 ·
O de GEEZ.

Most of this was written on the other forum. Unfortunately a certain someone was making it the place it has become and I stopped contributing to the post. I though the information I put together might be interesting to the folks over here so I thought I would copy the posts here. The conversation led to a driving tool Mary and I use Extreme Geez.

Andy Dunn asked me about the tool, and I went on a rant about it. If any of you are serious about learning to do well in autocross, this tool is worth a VERY GOOD LOOK!

This is my response to Andy. (edited for flow and stuff)

I think it is a FANTASTIC learning tool!! It will tell you whether you or your car suck :D .

We had a horrible time last year(2001) in the middle of the season at a pretty important race. It was the North West SCCA Divisional. We were excited about the event…. and nothing went well. To put it frankly… we SUCKED… at least that’s what we thought.

To give a baseline run, here is a screen capture of my run at the American Muscle Car challenge just a few months before this event. This was on Hoosier Street legal DOT radials.

As can be seen, sustained G's in the 1.35 range, and peaks near 1.5. Also note the ratings for overall driving, smoothness, aggressiveness, and usage rating.



At the divisional event, we were running the exact same tires as the above event and at the same site, so the same surface.

We were getting our buns kicked, and I could not understand it. The hoosiers had more than 50% of their tread left, nothing else changed except heat cycles on the tires.

At the AMCC we had about 50 runs or heat cycles on the tires, at the Divisional event we had about 75-80 runs/heat cycles.

The car pushed like crazy, the brakes would lock... We just could not get in the groove.

After I downloaded the Geez data, I knew instantly what was wrong. The grip was gone.... The tires fell off like a rock. Just a couple events before, and I was producing 1.35- 1.5 g's and now barely 1.1g's. You can tell the braking suffered also.



My driver rating wasn’t horrible, but I could not get in the groove because the car was so different.

After that event we decided to go back to the Kumho’s. We instantly lost 2 seconds a lap compared to the folks we benchmark against. This is a run a couple months after the divisional with the Kumhos. We lost about .2 g’s in cornering grip and really lost grip turning to the right.



I had not been able to figure it out, why we lost grip turning to the right. The cars grip remained about what it is in this run for the rest of last season and most of this year. I thought it might be corner balance and had played with the springs and front bars a bit and never could cure it. I thought it might be from my weight on the left side of the car.

So a few months back, I messed with the springs and the front bar based on a theory that I had. Basically re-corner balancing the car, loosening the bar mounts, and redoing the end links so the car did not have what ended up being pre-load on one side. On the next picture you will see I fixed the right and lift grip problem.



This run is of the American Muscle Car Challenge just a month ago, I was running Kumho's. These tires have had many many heat cycles, but faired much better than the hoosiers as they got old. However you can see the Kumho's don’t offer the ultimate grip of the hoosiers when new.

Everything else on the car was pretty much the same, with the exception of a power brake booster, and the ackerman change and stock brake pads.

The car felt wonderful. Still not the grip of the hoosiers, but pretty good.

The colors on the map represent your usage rating.

The car is capable of X amount of grip in any direction at one time. Geez knows what this is based on your sustained G's readings in all directions. This is also known as your friction circle. The idea is to ride the edge of the friction circle as you go around the track.

The USAGE rating depicted in the colors represented on the maps tell you how close you are to the edge of the friction circle at any given point on the track.

Light blue means your over 90% usage
Dark Blue over 80%
Pink over 70%
Red below 70%

So the more light blue you see the better. The more red the worst...

Geez has tons of these filters that allow you to analyze the data in many different ways.

This is an example of a 1998 National winning run by Mark Daddio. Notice how smooth his transitions from left to right are. Very smooth!! (this run supplied as a sample from the Geez program)



All this data is autocross related, and i understand it works pretty decent on the big track. I just have not played with it much there. I plan too.. Im just leary of worrying about something like the Geez or a Camera when on the track wheel to wheel..

David

[ November 15, 2002, 02:07 AM: Message edited by: David Borden ]
 

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David,
Looks like a terrific package. I saw the post on Meat’s forum; I refuse to post there any more myself. Does the package “draw” the circuit map itself with inertial navigation, or do you have to enter that?

Also, what do you use for data collection, the laptop or Palm? If the palm, do you have to unload it between runs? Is that an issue if you are sharing a car with another driver (thinking of the time required to dump the data and setup for second driver)?
 

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Very kewl. How does the bottom run have such a low Accel G substained, but still rate so high in aggressive. I can see where driving the thing like there's an egg under the loud peddle would create a huge smoothness #. But you would think that the low Accel # would have killed the run?

Still showing a high score on aggressiveness though? hmmm, Does the thing have traction control....lol
 

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Discussion Starter · #4 ·
Robert,

You do some small tweaks to get it to draw the map, but it is quite easy to do. Its pretty much automatic.

I use the Palm to data collect. Generally dont download it until I get home and can study it.

Its pretty quick if you want to do it at the track though.

For autocross it might be tough to try and analyse between each run but possible.

Kobrak,

Remember I said that each rating is based on the cars potential. That run was in a dodge neon... by someone else
so the acceleration was quite low, but it sure cornered well!

David
 
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