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).
Causes and tests conducted for body wind noise on the Wraith model.
| Identifier | ExFiles\Box 161\1\ scan0036 | |
| Date | 15th October 1937 | |
| To Rm.{William Robotham - Chief Engineer} from Rm{William Robotham - Chief Engineer}/FD.{Frank Dodd - Bodies} 15.10.37. BODY WINDNOISE. The quieter our chassis and engines become the more noticeable and objectionable have windnoises appeared. This is most apparent on the Wraith where we now have a really quiet car. We have carried outtests on the Brown Wraith 26.G.6. as this car seems to be even worse than the others for wind noise. It would appear from our tests that it is the air impinging on the windscreen and flowing round the sides of the car, catching all the irregularities such as hinges, door edges, recessed windows, etc. etc., all of which do their share in increasing the noise. We also have audible noise from the slots at the side of the sunshine roof, and from the leading edge. It is common practice on our bodies to give a clearance of .1875", or more, between the door edge and body framework. The top of the doors are left flat, while usually the front and rear door edges have an overlapping lip of approx. .5" We rely entirely on keeping out the wind by fitting a seal of rubber tubing bound with cloth, or leather, whichever upholstery is used on the car. On the car we tested it was found that the draught piping was totally inadequate to cope with the wind coming through the door spacings. This was proved by sealing all the spacings with protective adhesive tape. The wind noise from the sunshine roof was also cut down to a passable amount through sealing off the sidegrooves and placing a strip over the leading edge. On other cars we have found that the coachbuilders have left the roof drain vents facing forward at the top of the windscreen. This has also been a means of making a whistle for the wind. continued | ||