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).
Analysis of power curve C, air resistance coefficients, and tyre losses for a Phantom III at Brooklands.
| Identifier | ExFiles\Box 109\4\ scan0097 | |
| Date | 26th June 1939 | |
| -2- Rm{William Robotham - Chief Engineer}/TAS.{T. Allan Swinden}1/JH.26.6.39. There is good reason to believe that the power curve C is a true picture of the power available when the car was at Brooklands. Assuming that the tyre losses are not greatly in excess of any tyres already tested - and there is no reason to believe that they should be - the air resistance coefficient K for the car works out at .00178. This is based on a lap speed of 86.6 m.p.h. and the same frontal area as a Phantom III. Phantom III K is in the region of .0018. If a 'K' value is obtained from the test bed clutch H.P. curve and the same maximum speed it is far too high at nearly .0024. Rm{William Robotham - Chief Engineer}/TAS.{T. Allan Swinden} | ||