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).
Outlining the general basis for testing wind noises in cars.
| Identifier | ExFiles\Box 160\2\ scan0172 | |
| Date | 20th February 1934 | |
| X4578 [redacted text] copy to [redacted text] RVL/IH.20.2.34. re:- WIND NOISES IN CARS. GENERAL BASIS ON TESTS. The only wind noises which we propose to pay attention to at the moment are those set up by the straight ahead motion of the car in still air. Testing can be done, therefore, only on days when there is relatively no wind. Later we hope to see if there is anything to be learned from cross winds, but we believe that the head on wind is the source from which the bulk of the noise complained of is emanating. The investigations of necessity at this stage have to be qualitative, dealing with cause and effect, rather than quantitative, because we have no soundmeter. We hope that Rn{Mr Robinson} will give us some idea as to what General Motors use as a suitable acoustic "rig-up", as we believe mentally they have progressed some way in this matter. We are using as the basis comparison the Essex Terraplane Saloon, and we are endeavouring to make one of our cars as good as it is, and, at the same time, if possible, to reproduce on the Terraplane the noises of our cars. Also, it is important when taping ridges and gaps and modelling features on any car, therefore obtaining improvements, that when each of these has been done consecutively, finally all should be removed and the car tried again in the same direction on the same road, in order to appreciate the total effect. It is human soon to get used to an improvement and start to appreciate a secondary defect. In each stage the testers standard of excellence goes up and to revert finally to the original condition, gives him the true comparison. At one stage soon we would like to have the Essex Terraplane here, so that we can refer back to the final standard. In parallel with the tests on our cars we are hoping to make tests on the best american Cars. -1- | ||