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).
On road acceleration and tractive resistance tests to investigate car performance differences.
| Identifier | ExFiles\Box 113\2\ scan0033 | |
| Date | 1st March 1923 | |
| To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c. to CJ. c. to E.{Mr Elliott - Chief Engineer} c. to Da.{Bernard Day - Chassis Design} c. to BY.{R.W. Bailey - Chief Engineer} c. to EP.{G. Eric Platford - Chief Quality Engineer} Handwritten: X1725 Hs{Lord Ernest Hives - Chair}4/LG2.3.23. ROAD ACCELERATION AND TRACTIVE RESISTANCE TESTS. Handwritten: X1725 X4578 We attach a report and blueprint of tests carried out by my Assistant (Mr. Robotham). The object of these tests was to enable us to try and find the reason why some cars give a better performance than others. We have always been faced with the problem that cars of exactly similar parts give a noticeably different performance on the road. The difference cannot be measured by the ordinary dynamometer tests. Our endeavour is to get out a balance showing how the H.P. is used up on the road. The value of the tests and accuracy of them should improve as we take particulars of more cars. We also propose to analyse the losses between the H.P. obtained on the bench test and the H.P. on the road wheel dynamometer. At present we do not know the exact value to give to the H.P. which is obtained on the road wheels. For instance, the dynamometer H.P. of the 40/50 cars made at Springfield, is definitely higher than the H.P. we obtain on the cars at Derby. This is due to the fact that they use a different type of dynamometer. Instead of the power being transmitted from the tyres, it is taken from a belt pulley fixed to the road wheels. Hs.{Lord Ernest Hives - Chair} | ||