Performance chart comparing road wheel brake horsepower against engine RPM for various car configurations, with a table of lap speeds from Brooklands.
| Identifier | Morton\M7\ img050 | |
| Date | 1st November 1925 | |
| BROOKLANDS NOV. 1925 TABLE: CONDITION OF CAR | LAP SPEED MILE | HALF MILE High Compn. Sports Car 17 Tooth Axle | 79.2 | 80.4 Standard Condition C.O. Closed | Standard Condition C.O. Open | 80.5 | 82.6 Standard Touring Car 4 - 1 Comprn 15 Tooth Axle | Standard Condition C.O. Closed | 74.13 | Sports Car Front Wings Removed Top Panel of Wind Screen Raised C.O. Open | 87.8 | 89.6 CHART: Axis Y: ROAD WHEEL B.H.P (30, 40, 50, 60, 70, 80, 90) Axis X: ENGINE R.P.M. (500, 1000, 1500, 2000, 2500, 3000) Chart Annotations: C.O. OPEN C.O. CLOSED Standard Car Comp. Ratio 4.1 - 1 High Compression 5.2 - 1 2750 R.P.M. 89 M.P.H 17x52 AXLE | ||
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).