Spreadsheet Calculators

[hivewax]

If anyone has any Excel spreadsheet calculators to share, please post up. I found this tire size calculator online and changed it up a bit.

 

[Sluggo]

Anything in particular you are looking for?

 

[hivewax]

Maybe an engine RPM, HP/torque equations. There are online calculators, but I'd like to see the formulas.

 

[Sluggo]

Maybe an engine RPM, HP/torque equations. There are online calculators, but I'd like to see the formulas.

I looked at the formulas in that tire calculator, they could be pared down and simplified but they work correctly.
Got a link?

 

[Sluggo]

http://www.ajdesigner.com/phphorsepower/horsepower_equation_rotating_torque.php

Torque=5252xhorsepower divided by speed(rpm)

450 horsepower at 5000 rpm is

5252 x 450 =2363400
2363400 Divided by 5000 =472.68

 

[hivewax]

Thanks. What about engine RPM based on rear gear and transmission gear ratios? As I changed my rear gear from 3.00:1 to 3.50:1 and my tire diameter changed. I'll need to change the speedometer.

 

[hivewax]

Links...

http://pro-touring.com/forum/showthread.php?t=13216

http://www.csgnetwork.com/multirpmcalc.html (engine RPM equation embedded)

 

[hivewax]

rpm = mph x gear ratio x 336 / tire diameter

http://www.superlift.com/library/gears.asp


rpm = (mph * gear * final * 88) / circumference

rpm = engine rpm
cir = tire cicumference, in feet
gear = gear ratio of your car
final = final drive ratio of your car
88 = combines several conversion factors

http://www.type2.com/library/misc/calcspd.htm

 

[hivewax]

Updated the tire spec calculator to include engine RPM. Add any other calculations to the spreadsheet and post it up. Thanks.

 

[hivewax]

Added speedometer calculator, since I haven't changed the speedo gear out yet...