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).
Graphs showing air pressure under the bonnet versus road speed for a Chassis 20 EX under various conditions.
| Identifier | ExFiles\Box 12\7\ 07-page189 | |
| Date | 18th September 1931 | |
| CHASSIS 20 EX AIR PRESSURE UNDER BONNET (RECORDED BY U TUBES) STANDARD UNDERSHIELDS. RESULTS GIVEN ARE AVERAGE OF FOUR READINGS. TWO ON EACH SIDE OF ENGINE, HALF WAY BETWEEN BONNET SIDE HINGE & BOTTOM OF SIDE PANEL, ONE AT FRONT END & ONE AT REAR END OF ENGINE. TOP GEAR PRESSURE UNDER BONNET (INCHES OF WATER) ROAD SPEED (M.P.H.) LBS / ☐ IN PRESSURE UNDER BONNET (INCHES OF WATER) ROAD SPEED (M.P.H.) LBS / ☐ IN PRESSURE UNDER BONNET (INCHES OF WATER) ROAD SPEED (M.P.H.) LBS / ☐ IN FLIP FLAP SHUTTERS (3 EACH SIDE) SHUTTERS OPEN -----------X SHUTTERS CLOSED -------o RADIATOR FITTED WITH 6 x 7.5 M/M MATRIX TUBES. | ||