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).
Report comparing 25 HP and 30 HP cars, with maximum speed test results for various models and chassis.
| Identifier | WestWitteringFiles\U\August1930-November1930\ Scan026 | |
| Date | 25th August 1930 | |
| -3- will get a good reputation when compared with the average 30 H.P. car. On the other hand the 25 HP. R.R. must be similarly suffer due to its short stroke. We have nothing at all to spare on the 25 HP. when competing with these cheap American cars for performance. On the acceleration curves we give, that of the 40/50 was taken in France on the poorest fuel obtainable, before the heat to the hot spot was increased - hence it is not up to standard at low speeds. ACCELEROMETERS. The calibration curves given indicate what we already know. DATA. The car weights, tyre dia., direct drive ratio, were all accurately measured on the track. 20 HP. MAXIMUM SPEEDS. We took the opportunity of getting some 20 HP. maximum speeds while on the track. The results obtained were as follows :- ½ Mile. Lap Speed. GLW{Mr Wilde}-83 Saloon fitted with 112° Camshaft & 5.75 C.R. 69.77 68.03. (Hs{Lord Ernest Hives - Chair}/Ma.1/AL.26.4.30). GXO-15 Open Touring. 64.18 64.26. 14-G4 Cabriolet (10,000 Miles car) 64.29 62.64. Production Chassis. 62.5 61.48. These results are interesting in that they show the futility of comparing chassis with bodied cars for speed owing to the difference in windage. Also the appreciable gain due to the 112° camshaft and higher compression. | ||