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).
Testing and troubleshooting booming and air pressure issues in an exhibition car body on chassis No. 147-GY.
| Identifier | ExFiles\Box 137\4\ scan0265 | |
| Date | 18th March 1931 | |
| Mr. Davis. Exhibition body by Thrupp & Maberly on the second Chassis No.147-GY. There are sundry interesting points arising out of the work now finished in connection with this case. I use the word "finished" because we do not know what further steps to take in order to improve the conditions complained of. When I tested this body fitted to the second chassis about three weeks ago, I was surprised to find how remarkably free from the troubles complained of i.e. the booming at the high speeds the combination was, even on the over-run. After this the car went into Thrupps to have the body-work finished and sundry odd jobs attended to, these I find included a certain amount of work done to the roof, two spare wheels instead of only one at the sides, removal of the spare wheel fitting from the rear and the provision of a different luggage grid and a covering apron at the back. On testing the car on the completion of all work, it was found, and I confirmed this yesterday, that the old trouble complained of had returned to quite an extent. I spent much time with JLR and HO. and Thrupps endeavouring to isolate one or other points which might be contributory, but nothing we did appeared to have more than a very slight advantage, for instance the wheels were taken off the rear, the covering apron was taken off and we even went to the length of entirely disconnecting the two centre sub-frame supports for a test run in order that there should be no metallic contact between the body and the side-members. At no time was any improvement to be obtained except by either closing the big window across the middle of the car or opening wide the two rear windows. Doing either of these things appeared to reduce the painful intermittent air-pressure which worried ones ear-drums between 55/65 m.p.h. The view finally taken was that the car is definitely better than with its original chassis, but probably not more than about 15%. | ||