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).
Performance data sheet for Dunlop racing tyres, detailing mean lap speeds with various carburettor configurations.
| Identifier | ExFiles\Box 155\1\ scan0032 | |
| Date | 23th July 1932 guessed | |
| DUNLOP RACING TYRES. SHEET (1). 6.75 x 21" Tyres. Rolling Circumference 107" at 50 lbs/sq.in. 22-EX. 11 x 41 Axle. 114° Camshaft. Car Weight 50.5 Cwt. Condition of Car. Mean Lap Speed. C.O. Open. C.O. Closed. Std. R.R. Carb. & Silencer. 84.84 80.98. Two S.U. Carbs. with Air Silencer. 91 M.P.H. 84.13 R.R. Semi Expanding Carb. with Air Silencer. 88.35 83.7 R.R. Semi-Expanding Carb. Air Valve Removed. 90.72 85.5 | ||