Percentage Differences

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Vitamin K

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So, this is just food for thought, but I found it kind of interesting.

Just looking at the latest results for the BASX class, the lowest average speed (in prelims) was 2.945, while the highest average speed was 3.0274. That's a percentage difference (assuming I am math-ing correctly) of about 2.72%.

So a difference of less than 3% separates the top from the bottom.

For some crazy thin margins, compare the first (2.945) and second (2.955) finisher, and we get a margin of about .34% difference in time.

Even for the middle of the pack, gaining half a percentage point of improvement would put them at the number one spot.

For me, chasing that sub-3 average with my graphite, stock-wheels-and-axles car, I'm lagging behind by about .61%.

So keep chasing those fractional percentage speed improvements. I guess that's why every little bit helps! /images/boards/smilies/wink.gif
 
I saw this post on car time averages, so I thought I would share data from one of my cars.

While I was not happy with where my Street Stock car Blowfeld finished, I do see some signs of improvement over the the car Late Night Sneaky that I entered in the June race. Overall Blowfeld was the faster car and if I can get the wiggles out of it, (yes I do believe that I kept everyone at the race on the edge of their seats when my cars run) it should be even faster in August. Everyone says to race against their own times, work on car prep, and try to get faster each month.

SS%20Times_zpswgllo2ky.jpg
 
Vitamin K said:
So, this is just food for thought, but I found it kind of interesting.

Just looking at the latest results for the BASX class, the lowest average speed (in prelims) was 2.945, while the highest average speed was 3.0274. That's a percentage difference (assuming I am math-ing correctly) of about 2.72%.

So a difference of less than 3% separates the top from the bottom.

For some crazy thin margins, compare the first (2.945) and second (2.955) finisher, and we get a margin of about .34% difference in time.

Even for the middle of the pack, gaining half a percentage point of improvement would put them at the number one spot.

For me, chasing that sub-3 average with my graphite, stock-wheels-and-axles car, I'm lagging behind by about .61%.

So keep chasing those fractional percentage speed improvements. I guess that's why every little bit helps! /images/boards/smilies/wink.gif

Wait, how are you doing that math? Don't you need a baseline first?
 
Yeah, I think there's a fault in this math, you are assuming the fastest possible speed is 0 seconds and slowest is 3.0274 seconds, in reality a better percentage would come from more reality based times.

I'd use the BASX record speed of 2.9416 for the fastest time.

Then I'd run an uncut, unmodified BSA block right out of the box, unmodified axles and wheels in the provided slots, with no lubrication, and running that down the track, this will give you the slowest time, or your baseline.

This would give a more scientific view of the speed differences....
 
CivilWarTalk said:
Vitamin K said:
So, this is just food for thought, but I found it kind of interesting.

Just looking at the latest results for the BASX class, the lowest average speed (in prelims) was 2.945, while the highest average speed was 3.0274. That's a percentage difference (assuming I am math-ing correctly) of about 2.72%.

So a difference of less than 3% separates the top from the bottom.

For some crazy thin margins, compare the first (2.945) and second (2.955) finisher, and we get a margin of about .34% difference in time.

Even for the middle of the pack, gaining half a percentage point of improvement would put them at the number one spot.

For me, chasing that sub-3 average with my graphite, stock-wheels-and-axles car, I'm lagging behind by about .61%.

So keep chasing those fractional percentage speed improvements. I guess that's why every little bit helps! /images/boards/smilies/wink.gif

Wait, how are you doing that math? Don't you need a baseline first?

I could very well be abusing numbers. Here's how I calculated the percent differences.

Top finisher 2.945 seconds and last finisher 3.0274 seconds.

Percent difference = 100 - ((2.945 / 3.0274) * 100) = ~2.722%

Take the middle finisher, at 2.9563. If we take half a percent of that time and then subtract it from the total 2.9563 - ( (2.9563 / 100) * .5 ) = 2.942. So even an "average" competitor is less than half a percentage point (of their own time) of difference away from the top finisher.

Like I said, I could very well be abusing numbers. /images/boards/smilies/smile.gif
 
CivilWarTalk said:
Yeah, I think there's a fault in this math, you are assuming the fastest possible speed is 0 seconds and slowest is 3.0274 seconds, in reality a better percentage would come from more reality based times.

I'd use the BASX record speed of 2.9416 for the fastest time.

Then I'd run an uncut, unmodified BSA block right out of the box, unmodified axles and wheels in the provided slots, with no lubrication, and running that down the track, this will give you the slowest time, or your baseline.

This would give a more scientific view of the speed differences....

Okay, I think I have a better way to frame the data. What the numbers can tell is this: What percentage increase would be needed by the given time to beat the target time?

So we have our first place finish, which is 2.945 in this race.

Okay, so we have our second place finisher, at 2.9455. To get to the winning time, he would need to shave (2.9455 - 2.945) = 0.0005 seconds from his average time. (0.0005 / 2.9455) * 100 = .01697%

So if the second place finisher can build a car .017% faster, he'll have the top car next time, assuming the top car doesn't get faster!

I think. Will check my math after dinner. Quite probable I'm making more errors. /images/boards/smilies/smile.gif
 
Abusing numbers? Yeah, a little bit, but they are still truthful even if slightly deceiving. A 2% difference seems minuscule, but using the same math:

A new V6 Camry does the 1/4 mile in about 14.5 seconds.
A new base Corvette does the 1/4 mile in about 12 seconds.

That is a 17% difference.

CivilWarTalks theoretical base PWD car would probably still run a 3.5. A difference of about 16% from the top BASX. Or... roughly the same as a Corvette vs Camry race.

Using that stat line small numbers are a big difference. I like CivilWarTalks idea of using a high and low model for calculating it. Maybe the low should be the theoretical minimum for a PWD car if aerodynamics are negated and friction is zero.
 
The difference from first to last was over 8 hundredths. No matter what math you use that is a huge difference in PWD. each .01 is a big accomplishment.

http://www.pinewoodderbyonline.com/post/translate-2-car-lengths-6967520

You could look at the stats like a grade level or a % depending on your competition. If 2.9450 putt up by Mr. Kinser is an A+ or %100 and a 3.0274 was your F or %50 grade you could get your grade in the BASX class. so you could look at the stats like this in terms of pro cars, 3.02 = F grade, 3.00 = D grade, 2.98 = C grade, 2.96 = B grade, and 2.94 = A grade. This is a way to look at the numbers. Damn this seems harsh hope I don't hurt anyone's feelings but this is how I judge myself against my fellow racers.
 
BulldogRacing said:
The difference from first to last was over 8 hundredths. No matter what math you use that is a huge difference in PWD. each .01 is a big accomplishment.

http://www.pinewoodderbyonline.com/post/translate-2-car-lengths-6967520

You could look at the stats like a grade level or a % depending on your competition. If 2.9450 putt up by Mr. Kinser is an A+ or %100 and a 3.0274 was your F or %50 grade you could get your grade in the BASX class. so you could look at the stats like this in terms of pro cars, 3.02 = F grade, 3.00 = D grade, 2.98 = C grade, 2.96 = B grade, and 2.94 = A grade. This is a way to look at the numbers. Damn this seems harsh hope I don't hurt anyone's feelings but this is how I judge myself against my fellow racers.

Bulldog, by this math I am a C student. YES!!!
dance
 
"You could look at the stats like a grade level or a % depending on your competition. If 2.9450 putt up by Mr. Kinser is an A+ or %100 and a 3.0274 was your F or %50 grade you could get your grade in the BASX class. so you could look at the stats like this in terms of pro cars, 3.02 = F grade, 3.00 = D grade, 2.98 = C grade, 2.96 = B grade, and 2.94 = A grade. This is a way to look at the numbers. Damn this seems harsh hope I don't hurt anyone's feelings but this is how I judge myself against my fellow racers."

Is a 2.97 a B- or a C+? Need to know because it will determine whether I'm on restriction or not.
 
tinman racing said:
Bulldog, by this math I am a C student. YES!!!
dance

"I am talking about your potential."
"mm hmm"
"You're not a C student."
"yeah"
"Yet your gettin' C grades. It's the disparity there that concerns your dad and me."
"uh huh"
"You know what a disparity is?"
"YEAH!!"
"Okay...well. That's why we...we don't wantcha goin' out for hockey."
"AWW MAN! Come on!"
 
I wonder if the cars are going faster because it getting hotter out ?? My faster car picked up a good amount of speed over the first race and I did not even touch it.
My 2nd. car pick up some speed and I did a complete reprep with new Basx Pro wheels. After the first race the 2 cars were .0001 difference after 4 runs. Now the gap is
about .0025. May if I don't reprep the first car for another race or two I will make the finals --- L.O.L.