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).
Performance tests and analysis of a sports car versus a standard Phantom.
| Identifier | WestWitteringFiles\N\2October1925-December1925\ Scan224 | |
| Date | 30th November 1925 | |
| R.R. 493A (50 H) (D.D. 31, 12-6-25) J.H.D. EXPERIMENTAL REPORT -2- Expl. No. REF Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}/LG30.11.25. in the back of the car is considerable. Any delicate measuring instrument therefore suffers accordingly. It is perfectly clear from all our tests, however, that this sports car body as a whole is very little better than the standard car for speed work. As indicated in our previous report, removal of the front wings effected a large improvement The curve 'B' substracted from the cruve 'A' gives the H.P. available at any speed to accelerate the car. This has been plotted as curve 'C'. In order to find out whether the car on the track is giving the H.P. obtained on the dynamometer, we have taken the curve 'A' on Graph lll. and converted it to road wheel H.P. This road wheel H.P. curve should be coincident with curve 'C' Graph 1. if the carburetter is allowing the engine to develop its full power when accelerating. The two are plotted together in Graph Vlll, which shews at once that the carburation on the track must have been very good indeed. Graph lX. is a similar calculation for the last car we took on the track, 98-NK, a standard Phantom. As we mentioned at the time we were disappointed with the behaviour of this car. The curves indicate clearly that some slight fault prevented us getting quite the best out of it. The improvement we might have measured in acceleration is indicated in curve 2. Graph X. We take curve 2. as being the standard performance of a low compression Phantom as Graph Vlll. shews us that our carburetter will allow us to develop full power when accelerating if functioning satisfactorily. Graph lll. This indicates the great gain in low gear contd :- | ||