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).
Comparison of acceleration times and lap speeds for different exhaust and carburetor configurations.
| Identifier | ExFiles\Box 108\2\ scan0248 | |
| Date | 10th July 1939 guessed | |
| TWIN EXHAUST SYSTEM. 2 - 1.750" DIA. TAIL PIPES. 1.500" S.U. CARBS. TWIN EXHAUST SYSTEM. 2 - 1.750" DIA. TAIL PIPES. 1.750" S.U. CARBS. SINGLE EXHAUST SYSTEM. 1 - 1.750" DIA. TAIL PIPE. 1.750" CARBS. 10 -20 m.p.h. 4.4 secs. 4.6 secs. 4.6 secs. 20 -30 4.2 " 4.4 " 4.6 " 30 -40 4.5 " 4.5 " 4.6 " 40 -50 4.8 " 4.6 " 5.0 " 50 -60 5.2 " 5.2 " 6.2 " 60 -70 6.7 " 6.6 " 7.8 " 70 -80 9.4 " 8.5 " 12.2 " TOTAL 39.2 secs. 38.4 secs. 45.0 secs. BEST LAP SPEED 88.46 m.p.h. 89.74 m.p.h. 84.41 m.p.h " ½ MILE " 92.78 " 93.26 " 88.24 " | ||