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).
Analysis of vehicle performance increases from various modifications, comparing against previous results at Brooklands.
| Identifier | ExFiles\Box 179\2\ img085 | |
| Date | 22th December 1931 | |
| -2- Ha/BM/M.22.12.31. cont'd At 70 M.P.H. Carb. 8 B.H.P. Comp Ratio. 4 B.H.P. Cut Out. 7 B.H.P. --- 19 B.H.P. on 70 B.H.P. or 27% increase. At 80 M.P.H. Carb. 11 B.H.P. Comp Ratio. 4 B.H.P. Cut Out. 7 B.H.P. --- 22 B.H.P. on 60 B.H.P. or 36% increase. As regards performance with these increased powers, 18-G-4 lapped Brooklands at 78.43 M.P.H. and did 90.3 M.P.H. over the half mile with 89 clutch B.H.P. which is about what we shall get (H82/47.29.8.31.) In quoting Brooklands figures it should be noted that 18-G-4, our last 10,000 miles car has only a Brooklands lap speed of just over 70 M.P.H. and yet frequently ran up to 80 M.P.H. in France and a maximum of 84 M.P.H. actual was recorded under favourable conditions. It would therefore be fair to consider the proposed car with a lap speed of 80 M.P.H. as an 85 M.P.H. proposition. The only alterations from 20-G-4 to give this result would be pistons, cut out control, and throttle edge slow runner on the carburetter. Ha/BM. Attached : Ra.61. | ||