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).
Investigation into exhaust noise on the Phantom III vehicle.
| Identifier | ExFiles\Box 93\1\ scan0098 | |
| Date | 23th October 1937 | |
| WYMAN Shall not do much on the PIII exhaust system for the present. Aile Do you think new camshaft in 35E.X. & 37- any better for exhaust noise S/W. Rm.{William Robotham - Chief Engineer} 323. Cx{Major Len W. Cox - Advertising Manager}4/KW23.10.37. I tried the Phantom III with the latest tyres and I could not trace any noise from them. The greater silence thus obtained throws more into prominence the noise from the exhaust of the P.III, particularly at about 25 m.p.h. I am doubtful whether a cure on the lines of what you have temporarily applied to the 25/30 would do, because we have already found on the 25/30 that whereas the 30 m.p.h. drone has gone the hissing at high speeds is far more objectionable, and we have had to move it again from the 25/30. Presumably the same would result on the P.III. We are of course willing to try any such temporary application, but I do consider this noise very important and we ought to try and cure it as soon as possible. In the Minutes of the last Chassis Conference at W. it was recorded that we expressed the hope that now a silent exhaust system had been produced as on Wraith - we should be able to have a similar improved effect on the Phantom III at the earliest possible moment. No doubt in due course we shall be hearing from you as to what you are able to do in this respect. Cx.{Major Len W. Cox - Advertising Manager} | ||