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).
Tests and observations on vehicle vibration and 'boom' issues, comparing Phantom I and Phantom II models.
| Identifier | Morton\M19\ img050 | |
| Date | 19th March 1931 guessed | |
| - 2 - (2) Steering column isolated. With the rear engine feet removed this has sometimes a marked effect. (3) Frame side members damped by jacks at different points, also by lead weights. No appreciable improvement. (4) Gearbox removed. With the car stationary no improvement can be detected. (5) Dash damped with asbestos etc. No appreciable result. (6) Torque reaction dampers. If too tight bring up booms. Body ventures. (1) Semi isolation slacked off. This almost invariably produces a marked improvement. (2) Body lifted off chassis in front. No result. (3) Body lifted off chassis completely. Still booms. (4) Central partition up and down. In some cases boom in front seats reduced 40% by lowering partition. (5) Front floorboards isolated from their supports with rubber. Boom not materially altered. General impressions of P.I. Vibrations actually worse than on P.II but no resonance in the bodies we have so far tried. We have tried a P.I. fitted with a subframe, the car did not boom. Tests of a representative number of P.I. and P.II's in London show that the characteristic differences between the two chassis is so great that it cannot be entirely attributed to the general alteration in coachwork design, and therefore we continue to look for some point we have missed in which P.I. is different from P.II. HS{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||