Useful Formulae

[JenkinsComp]

I thought I'd kick this thread off:

bhp = torque x rpm / 5252

To calculate Trap Speed, when you know tyre size, rpm, and axle ratio

Trap Speed in mph = (Wheel Speed/336.13) x Tyre Diameter in inches

Wheel Speed = RPM / (rear axle ratio x gear ratio)

This formula calculates tractive force to the rear tyres.

F = (u * Wb / L) / (1 - h/L u + 2 ur / Nft KoF/Ko)
Where
Tractive Force (F) in lbs
Vehicle Mass (W) in lbs
Longitudinal Distance from front axle to CG (b) in inches
Wheelbase (L) in inches
CG Height (h) in inches
Coefficient of Friction (u)
Roll stiffness front suspension (KoF) in Ftlbs/degree
Total Roll stiffness suspension (KoR) in Ftlbs/degree
Tire Radius ( r) in inches
Final Drive Ratio (Nt)
Track Width (t) in inches





Other useful conversion factors
1 kilometre = 0.6215 miles
1 Kilo = 2.205 Pounds
1 cubic inch = 16.387064 cubic centimetres
1 BHP = 750.1 Watts or 0.7501 KiloWatts
1 Imperial Ton = 2240 Pounds
1 Metric Tonne = 1000kgs or 2205 Pounds
1 Pint = not enough!

Edited by JenkinsComp on Wednesday 11th October 12:14

Edited by JenkinsComp on Wednesday 11th October 12:59

[Time Machine]

That's a bunch of useful stuff, cheers. One thing though:

JenkinsComp said:

1 BHP = 750.1 Watts or 0.751 KiloWatts

750.1W would equal 0.7501 kW, not 0.751

Not that we are too likely to need that conversion unless talking to continental types :-)

[JenkinsComp]

oops, typo!