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).
The Phantom II's performance at Brooklands, discussing potential gearing changes and ride quality.
| Identifier | ExFiles\Box 29\3\ Scan192 | |
| Date | 11th October 1929 | |
| HS{Lord Ernest Hives - Chair}) From R.{Sir Henry Royce} EP{G. Eric Platford - Chief Quality Engineer}) DA{Bernard Day - Chassis Design}) R.2/M11.10.29. c. to Sg.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} C. X.7770 X.7771 788 X.7350 PHANTOM II-BROOKLANDS RECORD. The speeds of 80 and 83 MPH. relatively are about as much as one would expect for the 2 cars mentioned, namely, the large cab. de ville, and the open tourer, with full equipment - windscreen, splashers, etc. Supposing that the open car was geared for the best speed irrespective of acceleration, and assuming the possibility of getting 90 MPH., what would be the change of the axle ratio, and have we such a gear available. Naturally, I say this for really high speed enthusiasts who do not mind changing gear. Personally, I should think that we require a ratio of back axle gear of from 75 to 80% of the present ratio, so as to bring the engine to just past its maximum HP., with a speed of about 90 MPH. I do not suppose for a moment that such a car would give a good top gear performance on the ordinary roads, and also we ought to aim at getting the maximum peak of the power curve at higher speed, which we hope to do very shortly, but I thought as a stop gap it might be advisable to try a some-what altered back axle gear ratio, especially if we had got one already made. I should think it would not be absolutely necessary for it to be a hypoid - i.e. ordinary spiral bevel would do. The large car I rode in definitely gave me a feeling of insecurity, suggesting that it needed increased shock damping or stiffer springs. Can it be altered? It would be worse loaded; it would give you seasickness in the back seats. R.{Sir Henry Royce} | ||