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).
Preparation of a Bentley for the 1936 Tourist Trophy Race, including fuel, tyres, and aerodynamics.
| Identifier | ExFiles\Box 90a\6\ Scan015 | |
| Date | 13th July 1936 | |
| To Sg.{Arthur F. Sidgreaves - MD} from Ra. c. to Wor.{Arthur Wormald - General Works Manager} c. to E.{Mr Elliott - Chief Engineer} c. to By.{R.W. Bailey - Chief Engineer} x262 Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}19/KW.13.7.36. Car for the Tourist Trophy Race 1936. After a general discussion of the conditions, it has been agreed to fit the extremely large petrol tank to the Bentley for Ulster this year, with a view to attempting to run through the race non-stop. This means that the car will start the race with a load rather more than 2½ cwts. greater than last year, and the mean load over the axle for the race will be 1½ cwts. greater than last year. A small amount of this weight is due to the fact that the spare wheel is now being carried behind the driver instead of at the side. The main problem appears to us to be whether the tyre manufacturers will be able to produce treads to run the whole distance, in view of the increased weight and the fact that 25% more power will be put through the rear wheels. Personally we think it is quite possible that a stop will have to be made, in which case the car will be slower than had the 26-gallon petrol tank been used. However, we hope it may have a non-stop run. This year we had hoped that the Bentley would have had a body with reduced wind resistance. As we pointed out in Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}16/KW.6.4.36, it has been demonstrated by Dubonnet that whereas the standard Bentley requires 105 HP. to drive at 80 M.P.H., if a car is efficiently streamlined the same speed can be attained with 48 H.P. In November of last year we gave Hall a model of his car, a print of which we attach, from which it will be seen that the front wheels were entirely covered in. The back wings also were part of the body and not separate. This was a guess at the best we could do with our particular chassis. Wind tunnel tests showed that this would be about 20 M.P.H. faster than a similar car with last year's T.T. body. We were surprised to note that the 3.3 Bugattis, which are our direct competitors in the T.T., had adopted almost exactly this type of body. These streamlined cars won the French Grand Prix at the beginning of this month, and immediately followed it by winning the Grand Prix de la{L. A. Archer} Marne. They have since set up a record for a Sports car of 130 M.P.H. The Bugattis proved themselves to be very much faster than the Lagondas which were running in the same race, and which actually put in a higher lap speed than the Bentley at Ulster last year. | ||