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).
Series of graphs plotting air pressure under the bonnet against road speed for different gears and bonnet types.
| Identifier | ExFiles\Box 16\2\ Scan038 | |
| Date | 16th September 1931 | |
| CHASSIS 19 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 AND BOTTOM. TOP GEAR PLAIN BONNET ———o——— LOUVERED BONNET: ---x--- OF SIDE PANEL ONE AT FRONT END ONE AT REAR OF ENGINE. PRESSURE UNDER BONNET (INCHES OF WATER) ROAD SPEED (M.P.H) LBS/SQ IN. 3RD. GEAR PRESSURE UNDER BONNET (INCHES OF WATER) ROAD SPEED (M.P.H) LBS/SQ IN. 2ND GEAR PRESSURE UNDER BONNET (INCHES OF WATER) ROAD SPEED (M.P.H) LBS/SQ IN. PLAIN BONNET: ———o——— LOUVERED BONNET: ---x--- RADIATOR USED WAS FITTED WITH 6x7.5MM. MATRIX TUBES WITH 4 INDENTATIONS. | ||