Has anyone analized the rpm of the wheels? I can generally look at distance traveled and base it on circumference but obviously that does not account for the fact that it starts at zero and reaches a maximum somewhere after the hill then decreases back down again.
Rpm
- Thread starter Peerless Racing
- Start date
I think about a year ago or so, someone calculated max speed of a street stock at 10.5mph. You can figure it out from there.
The math we did at work was approx. 3000 rpm. The wheels took 3 seconds to travel 504"(42') at a circumference of 3.5"approx. meaning it rotated 144 times approx. so time 20 gives an rpm of 2880. The 2880 is the number if the car was at a consistent speed the entire time which it wasn't, so I know I'm approximating but I also know the wheel did not peak at 3000.
3phase,It was a question someone asked me, and I think the effectiveness of the lubricant and its proper viscosity is dependent on velocity other than that it is probably not important.
3phase,It was a question someone asked me, and I think the effectiveness of the lubricant and its proper viscosity is dependent on velocity other than that it is probably not important.
3phase said:
I always thought the RPM of the wheel didn't matter.
If the fastest and slowest cars have matching wheels, do they not travel the same exact distance?
They travel the same distance but the faster car does it in a shorter time so it's wheels would be spinning at a higher RPM, right?
Oops forgot to carry the one. It is 2996.5 assuming the 3-3/4" circumference wheels approx. at 10.5 MPH. Sorry bracketracer.
G
Guest
Guest
bracketracer said:They travel the same distance but the faster car does it in a shorter time so it's wheels would be spinning at a higher RPM, right?3phase said:I always thought the RPM of the wheel didn't matter. If the fastest and slowest cars have matching wheels, do they not travel the same exact distance?
Doesn't BR sound like Hal from "A Space Oddessey" when he states the obvious!
LOL!!
OK fellas,
I am very confused.
If we take 2Pi R we get 5.338" on one revolution.
So if Besttrack says 442 that means 83 revolutions per race. Right?
I might need to ask my 6th grader./images/boards/smilies/confused.gif
My 6th grader says the wheel will rotate 120.3 times.
1.17 x 3.14 divided by 442"= 120.3
My 6th grader says the wheel will rotate 120.3 times.
1.17 x 3.14 divided by 442"= 120.3
Rocket car said:My 6th grader says the wheel will rotate 120.3 times.1.17 x 3.14 divided by 442"= 120.3
If you use jig, I think you can drop it by 2 tenths; maybe even get under 120. I think there is a badge for that.
laserman said:bracketracer said:They travel the same distance but the faster car does it in a shorter time so it's wheels would be spinning at a higher RPM, right?3phase said:I always thought the RPM of the wheel didn't matter. If the fastest and slowest cars have matching wheels, do they not travel the same exact distance?
Doesn't BR sound like Hal from "A Space Oddessey" when he states the obvious!
LOL!!
OK fellas,
I am very confused.
If we take 2Pi R we get 5.338" on one revolution.
So if Besttrack says 442 that means 83 revolutions per race. Right?
HEY NOW! Be nice! LOL! He asked why RPM mattered. I was just reminding him that we race in time over distance.
I just use these formulas:
Pi R round.
Cake R squared.
B_Regal Racing said:Rocket car said:My 6th grader says the wheel will rotate 120.3 times.1.17 x 3.14 divided by 442"= 120.3
If you use jig, I think you can drop it by 2 tenths; maybe even get under 120. I think there is a badge for that.
I'm using Pinecar brand wheels and a rough circumference of 3.75" (you can mark the wheel and rotate it one time). I would like to know if the 10.5 MPH is at the bottom of the hill or approximated across the entire length of the track?
That's the number I get.
My reason for showing this is to share the method for converting things I learned in HS, and use all the time. We have inches per second, and want to get to revolutions per minute (rpms). One revolution of the wheel is 1.17 in * π (2πr or πd). And, of course one minute is 60s. Insert them into your equation such that things cancel out (inch over inch, s over s).
Hopefully this'll help someone here some day. /images/boards/smilies/thumb.gif
Code:
442in * rev * 60s = 26520 rev = 2405 rpm
3s 1.17in * π min 11027 minMy reason for showing this is to share the method for converting things I learned in HS, and use all the time. We have inches per second, and want to get to revolutions per minute (rpms). One revolution of the wheel is 1.17 in * π (2πr or πd). And, of course one minute is 60s. Insert them into your equation such that things cancel out (inch over inch, s over s).
Hopefully this'll help someone here some day. /images/boards/smilies/thumb.gif
Similar threads
