A physics question

paulkish

paulkish

old fart
Everyone wants to go fast and win, but just how can you go?

I've been to the Komplex in GA and I think many others have too. Let's say a Clone is 10hp and the kart and driver weigh in at 360 pounds. What is the maximum speed the little 10hp engine can push the kart around the track? If the track is slick you probably cannot use all the hp, but then lets make bite and then more bite, how fast can you go until you run out of hp?
 
I think it was 59 mph average lap speed in clone heavy at thanksgiving thunder... Probably could go back in mylaps and research...
 
Jncyall said:
I think it was 59 mph average lap speed in clone heavy at thanksgiving thunder... Probably could go back in mylaps and research...
Click to expand...

I hear ya with the 59mph, but can't you put more grip to it and go faster? What's holding you back, lack of grip or lack of hp? Is 60 possible?

Is 60 the limit?

Let's assume 60 is the limit. ok?

If your not going 60 then it's about why ain't you.

Do you have a lack of grip and can't put any more hp to it?
Are you slipping somewhere causing it to be loose, push or drift, keeping you from the 60?
If you put more bite to it, won't that get you to the 60 by getting rid of the slipping?
But what if your not slipping and can't get to the 60, then what do you do?
I guess you will have to free it up, or what?
But if your not slipping and you can't hit the 60, ... would you say it's locked down?
Your already not slipping and can't get to 60, how is putting more grip to it going to free it up?

I just don't understand it and it's got to be some physics problem keeping you from hitting 60.

... isn't the only way putting more bite or grip to it is going to get you faster, if you have hp available to use the extra grip? But what's really confusing is not slipping something somewhere on the track, when there more hp left to be used. And lets say you put more bite to it and go faster and hit the 60, is 60 then the real limit or can you go ahead and put more bite to it and go beyond the 60? What is the physical limit at the Komplex for a clone?

confusing read? I'm sure it is because it was a confusing write for me. ... :(
 
Paul, power is a very big factor in how fast you want to go. But if you don't have the grip to get that power down, your not using all you can. Thus you won't go as fast. Another factor is drag, and how fast and how well you can deflect that air hitting the kart. The less drag faster you go. The surface your racing on can also be a huge factor in how fast your going. Look at the Bonneville Salt Flats it is a very compact and salt creates less friction and it allows you to sort of glide.

So taking all factors into account, the speed you want to attain is dependent on so many things but it all comes down to getting the power to the ground.

I can't write big long paragraphs I lose my focus very...

Oh look a squirrel :)
 
"Oh look a squirrel :) "

It's out gathering nuts.

And by the way if you didn't notice it's dark out, you must of seen a skinny tailed night squirrel.
 
Once you get enough grip, unless the straights are too short, aerodynamics (drag coefficient) is going to be the limiting factor. Not having seen any wind tunnel data on karts, I have no idea what a representative drag coefficient would be....
 
My experience is there is always a limit, at least for the class your running that day. Generally the lap times are extremely tight with only 4 hundredths of a sec separating the leader from making the race. Then you go from stock heavy to open modified and you have a whole different group of times and usually .5 or more quicker. Then you go up to uas class and those guys blow the doors off with 3 times the hp or more and pretty good grip for the class. I'm sure there are limits in the physics of the drag, grip and hp of the kart, but heck, that's why we race! To be up front and the rush of speed and competition...
 
Way back in the 70's, a friend of mine, Chuck Matthews (Chuckles as he was later known), wrote a computer program to predict the maximum speed on a given race track, with known tires and known weather conditions with a known car. Doug was the race engineer for Doug Shierson Racing and if I recall, this was for Formula Atlantic and the driver was either Howdy Holmes or Jacques Villeneuve (the elder, Jacquo). The computer program predicted the theoretical fastest lap time. I think it was at Long Beach that Doug pressed the driver by telling him that the computer said he could go faster. After much harassment, either Howdy or Jacques came in and told Chuck something like "Tell that to your computer!" after he and just beaten the predicted fastest lap :)

I cannot remember if the program was written in Fortran, or Basic, or machine language, but I do remember it took almost 8 hours on the computer available to us at that time to crunch all the numbers. I tried to use a slightly modified version on my Apple IIe but it took over 24 hours for it to run. Perhaps now days, with the computer speed and power available, the engineers can do this prediction with accuracy. But the input parameters are not usually known to us mere mortals.

Just checked and it was Howdy Holmes at Long Beach in 1978.
 
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Quite calculable - if you know the frontal area of the kart and the drag coefficient. To get a real accurate #, you also need to know what the rolling resistance is. If someone actually knows these #'s, they're probably not going to tell, since they know someone who put in the work to find out what they are, or they did the work themselves.
 
The amount of info that F1 teams have they can pretty much predict their laptimes. And with all the live data they are getting back from the car they regularly tell the drivers which turns they need to drive faster or a different line.

mooney1el said:
Way back in the 70's, a friend of mine, Chuck Matthews (Chuckles as he was later known), wrote a computer program to predict the maximum speed on a given race track, with known tires and known weather conditions with a known car. Doug was the race engineer for Doug Shierson Racing and if I recall, this was for Formula Atlantic and the driver was either Howdy Holmes or Jacques Villeneuve (the elder, Jacquo). The computer program predicted the theoretical fastest lap time. I think it was at Long Beach that Doug pressed the driver by telling him that the computer said he could go faster. After much harassment, either Howdy or Jacques came in and told Chuck something like "Tell that to your computer!" after he and just beaten the predicted fastest lap :)

I cannot remember if the program was written in Fortran, or Basic, or machine language, but I do remember it took almost 8 hours on the computer available to us at that time to crunch all the numbers. I tried to use a slightly modified version on my Apple IIe but it took over 24 hours for it to run. Perhaps now days, with the computer speed and power available, the engineers can do this prediction with accuracy. But the input parameters are not usually known to us mere mortals.

Just checked and it was Howdy Holmes at Long Beach in 1978.
Click to expand...
 
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