From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Procedure for calculating a vehicle's acceleration curve using horsepower and weight data.
| Identifier | ExFiles\Box 124\2\ scan0170 | |
| Date | 14th May 1940 | |
| -2- Deduct losses a,b, and c, from the cluton h.p.curve and draw a new curve on a horizontal scale of m.p.h. Different curves w ill be obtained for direct gear and overdrive. MAXIMUM SPEED is indicated by the point at which the curve strikes the m.p.h. scale, i.e., accelerating power has dropped to zero. (3) Consider acceleration in increments of 10 m.p.h. If the acceleration time from 20-30 m.p.h. is required read off from the curve the power available for acceleration at 25 m.p.h. The force required to accelerate the car at this speed is then given by (power for acceleration in h.p.) x 375 -------------------------------------- 25 m.p.h. or P x 375 = F ------- V Then the actual acceleration of the car in m.p.h/sec = F x 22 = a ------ W where W = total weight of car and passengers + 6% for the inertia effect of the flywheel + 3% for the inertia effect of the roadwheels. And the acceleration time for the 10 m.p.h. increment = 10 seconds. -- a By this means a complete acceleration curve may be built up. | ||