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).
Test report detailing vehicle performance issues such as vibrations, jellying, and booms under different damper settings.
| Identifier | ExFiles\Box 11\3\ 03-page389 | |
| Date | 4th July 1931 guessed | |
| (2) Test (3) Dampers set to turn when a load of 35 lbs be applied at 5.25" radius (184 lbs ins). Load on the spring (C.1564 ex repair stores) being 250 lbs. This is the final setting used before the car left England. (a) Torque reaction at 9.5 m.p.h. causes the front wings to move slightly more than previous tests. This complaint was scarcely detectable before French petrol was used. (b) Jellying improved from previous test. It is thought that the gear lever and pedal movement are passable. (c) Booms very faint on the retard 62-58 and 48-40 m.p.h. with all windows up, but are still audible when the windows are open. (d) Vibrations. At 60 m.p.h. the gear lever rattles occasionally. At 73 m.p.h. engine starts to get very slightly rough and gets worse at 80 m.p.h. The car compared to a standard car is smooth. Test (4) Dampers dead solid. (a) Flapping of the wings worse at 9.5 m.p.h. (b) Jellying very slightly improved. (c) Booms are very slightly worse. (d) Vibrations at the same speeds as previous test only slightly worse. Gear lever rattles more consistent. From these tests it had been hoped to be able to get some improvement on steering road shocks. However since the radiator is centrally mounted no change has been noticed. Previously at Derby on 24-EX with a solid radiator, we decided that tightening torque reaction dampers made the steering road shocks worse. When 25-EX left England it was in a similar state to test (3). That is 250 lbs load on the torque reaction dampers. Springs. We do not consider it would be advisable to reduce the load owing to jellying, for this country. Although the high speed roughness is not perhaps not quite so good as we had hoped. Knowing the bad jellying of 25-EX in earlier days; we feel that cars in England might be more satisfactory with a load of 150 lbs on the torque reaction | ||