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).
Comparing the acceleration and retardation performance of Mr. Geoffrey Summers' car (117-MC) against a standard Phantom.
| Identifier | ExFiles\Box 160\2\ scan0072 | |
| Date | 14th December 1925 | |
| R.R. 4596 (2M) (B) (O.D. 31. 10-23) J.B.D. B.Y. EXPERIMENTAL REPORT Expl. No. 44578 REF: Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}/LG1412125 x4118 x1775 x8771 MR. GEOFFREY SUMMERS CAR - 117-MC. With reference to the report on the performance of this car. The readings for the acceleration are somewhat erratic. Taking the mean, however, and plotting them against the curve of a standard Phantom, we get the results shewn in Graph 1. Assuming 117-MC to weigh 46 cwts. ready for the test and that it is fitted with a 16-tooth axle, the curve is almost exactly what we expect. The increase in acceleration above 40 m.p.h. is due to the streamline body giving reduced wind resistance. From the max. speed attained, this body must have been exceptionally good for windage. The figures for the Vauxhall are hardly sufficient to enable a curve to be constructed. Plotting one roughly in Graph 11, however it will be observed that its top gear performance, even above 25 m.p.h. only, is very little better than the Phantom in spite of the fact that it is less than 2/3 the weight. Graph Y-Axis: RETARDATION FT/SEC.² Graph X-Axis: Road Speed M.P.H. | ||