Data acquisition

[integra55]

Toyos shouldn't enter into the equation. They are cheater tires that wear out faster than Hoosiers.

Sent from the Galaxy

wear faster than Ho-Ho's ? I put these on after the 24hr Labor Day '12 … there is still measurable tread on them … however many a-x's to finish up '12 and between 20 - 25 in '13 … plus 3 sessions on track at CMP (rain sessions)

I'm just waiting for the R2R to hit the market

You know, I heard on teh interwebz that was a problem with them Yotos. They figured out they was so sticky that the asphalt was coming off and stickin to teh tirez.

Sent from the Galaxy

[dewittpayne]

John Brown,

See this, for example.

Banking and aero don't add mass to the car so the lateral acceleration can increase over flat and no aero, but doubling the down force for the same vehicle mass produces less than twice the maximum lateral acceleration. While doubling the mass does decrease the maximum lateral g as seen in the Wikipedia article linked and every other book on vehicle dynamics.

[John Brown]

do you know who writes for Wikipedia? "Wikipedia is written collaboratively by largely anonymous Internet volunteers who write without pay. Anyone with Internet access can write and make changes to ..."

any. tom. dick. or. harry.... that's like taking competition driving lessons from the High School Driver Training Class.

But , I appreciate your enthusiasm DeWitt... you for sure try to suck up all the gizmos and documentary information.

I think data has a place in motorsports.. maybe just not AutoCrossing.. I have backed to backed with some of the fastest names in this sport..same car.. and the ability of even the best to duplicate a run is impossible.. so,every time we checked data, the driver always had an issue at someplace on course..no matter how small it was.. making useful data, well... not useful.
RR is a totally different deal.. breaking zones and full throttle zones are longer than most a-x courses in their entirety.. making input much more important and useful.

Id like to see you , next year... leave that crap at home.. and walk the course enuff with the fast guys to actually realize where you turn , break , and get on the throttle.
and with that said...
I sure do like all those lil twisty lines and different colors an shit. and specially seeing that number that shows how faast Im uh goin!! But, if Im not leading... I know right then that IM NOT goin faast enuff!! no download needed.

[thrdeye]

+1 - DeWitt, you want to go faster? Ditch the data and just drive. Besides, you have a pony car, you have to do all the things you shouldn't do to drive those things fast.

Anybody got Tony Bolton's number? lol

[steverife]

Rife...simple. You need to spin the car more

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From my experiences, spinning tends to makes me slower.

[thrdeye]

You know what I mean. It's clear from your posts that you don't feel comfortable getting the car to the limit. Get there, go past it, bring it back.

[John Brown]

John Brown,

See this, for example.

Banking and aero don't add mass to the car so the lateral acceleration can increase over flat and no aero, but doubling the down force for the same vehicle mass produces less than twice the maximum lateral acceleration. While doubling the mass does decrease the maximum lateral g as seen in the Wikipedia article linked and every other book on vehicle dynamics.

okay, I read this.. it sounds exactly like I told you.
"Coulomb friction theory says that the maximum horizontal force developed should be proportional to the vertical load on the tire."

[steverife]

You know what I mean. It's clear from your posts that you don't feel comfortable getting the car to the limit. Get there, go past it, bring it back.

Finding the limit isn't a problem. Any time I've ever went out with the mindset that I'm going to be aggressive, I basically lose the car the first time I lift.

The trouble is finding the balance between making the car turn in sweepers and keeping it under me during fast slaloms and braking.

[jcox07]

Dewitt, I can promise you that if you watch the fast guys and ask for them to help you with where your car should be going into the turns and you listen to them you will get much faster. I have watched JB, Mark, Robert and asked questions about where to enter and brake and when to get back in the gas and even though JB has never driven my car, all the advice he has given me has been spot on and that has made me much faster.

[dewittpayne]

John Brown,

See this, for example.

Banking and aero don't add mass to the car so the lateral acceleration can increase over flat and no aero, but doubling the down force for the same vehicle mass produces less than twice the maximum lateral acceleration. While doubling the mass does decrease the maximum lateral g as seen in the Wikipedia article linked and every other book on vehicle dynamics.

okay, I read this.. it sounds exactly like I told you.
"Coulomb friction theory says that the maximum horizontal force developed should be proportional to the vertical load on the tire."

It's proportional, of course, but, as i said, not directly proportional. Read the next sentence in that paragraph:

In practice, the maximum horizontal force Fy that can be generated is proportional, roughly, to the vertical load Fz raised to the power of somewhere between 0.7 and 0.9, typically.

[emphasis added]

If you double Fz, you increase Fy by a factor less than 2. For example, 2^0.7 = 1.6245, 2^0.9 = 1.866. A heavier car on the same tires will not be able to corner as fast as a lighter car. So much for the old Ford Pinto "road hugging weight" commercial. Aero load works the same way. If your aero downforce at a given speed is equal to the weight of the car, it will be able to corner faster, but the increase in maximum lateral g will be less than a factor of 2.

[dewittpayne]

Dewitt, I can promise you that if you watch the fast guys and ask for them to help you with where your car should be going into the turns and you listen to them you will get much faster. I have watched JB, Mark, Robert and asked questions about where to enter and brake and when to get back in the gas and even though JB has never driven my car, all the advice he has given me has been spot on and that has made me much faster.

I wouldn't have signed up for EVO school if I didn't think that I could learn something from better drivers. i'm not denigrating JB's or anyone else's skill as a driver. If I have given that impression, I apologize for the misunderstanding. The question is whether data acquisition is a useful part of the learning process. I think it is and besides, it's interesting in itself.

At the SCR Black Lake event I rode with someone during the fun runs after the event and discovered I was not merely lifting, but braking at a spot where I should have been accelerating. I ran a few runs in my car and still had a problem keeping my foot on the gas. That's the sort of thing I should be able to pick up from the data.

[jcox07]

Data is a good tool, but if you are going to try and get faster off of your data, it will not work. You can look at your run vs some one else in your car on the same course, but you will have to go by the seat of your pants to fill how much more you think you can drive the car into the corner before braking. The feel of the car going into the corner and how you set up the corner will help you get faster. I use data as well, but I go by the feel in the seat more than any thing else.

[thrdeye]

The only time I could see data being a big help is in a situation where you have to pick speed vs distance and vice versa. Sometimes those situations are not clear cut and are very car dependent. Data should be pretty conclusive in that situation

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[steverife]

I'd like to have a better idea of why some runs were faster than others...

[thrdeye]

So what data points can be used to figure that out? I honestly don't know.

I think it's obvious if you blow a turn or something, but beyond that, not sure what you would look at.

Maybe ask Hoelscher

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