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).
Graph showing acceleration test curves for a Phantom III with an overdrive gearbox, conducted at Brooklands.
| Identifier | ExFiles\Box 155\1\ scan0325 | |
| Date | 29th June 1937 | |
| To Rm{William Robotham - Chief Engineer} FROM Rm{William Robotham - Chief Engineer}/IMW.{Ivan M. Waller - Head of Chateauroux} CURVE No 1. 32 Ex. PHANTOM III OVERDRIVE GEARBOX. WEIGHT OF CAR AS TESTED 5978 LBS. ACCELERATION TESTS AT BROOKLANDS. 29-6-37. WEATHER - DRY, STRONG WIND, AIR TEMP. 16°C. LAP SPEEDS:- DIRECT DRIVE 85.8 M.P.H. OVERDRIVE 89 M.P.H. TIMED SPEED IN M.P.H. SECONDS. MAX. SPEED 90 M.P.H. MAX. SPEED 85.8 M.P.H. ① DIRECT DRIVE FROM 10 MPH & FROM 40 M.P.H. ② OVERDRIVE FROM 40 M.P.H. (NOTE. CURVES BASED ON FIGURES TAKEN UP TO 80 M.P.H.) | ||