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).
Performance and drag calculations for a Vanvooren Bentley.
| Identifier | ExFiles\Box 161\1\ scan0052 | |
| Date | 10th November 1937 guessed | |
| 4. Vanvooren Bentley by SR. Tunnel Drag = 164 lbs at 100 M.P.H. Projected Area = 21.6 sq.ft. Tunnel K.{Mr Kilner} = 164 / (21.6 x 100^2) = .000758 Real drag at 100 M.P.H. = .000758 / .88 = .000863 With 92.5 H.P. at Road Wheels. (like B.23.AE). and 79.6 H.P. available for Windage. (1) P = RV / 375 & (2) R = KAV^2 Substitute (2) in (1) P = KAV^3 / 375 or V = ( (375 P) / (KA) )^(1/3) Lap Speed V = ( (375 x 79.6) / (.000863 X 21.6) )^(1/3) = 117 M.P.H. or 187 K.P.H. Flying Half Mile 123 M.P.H. or 197 K.P.H. Max. Road Speed 129 M.P.H. or 206 K.P.H. There is a small error as the constant T.R. would then be (129 x 51) / 375 = 17.5 H.P. the road wheel total H.P. would be 97.100 H.P. which is what we might hope to give. EW. | ||