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 the performance benefits of the 'Paulin' Bentley compared to the standard model at various speeds.
| Identifier | ExFiles\Box 161\1\ scan0089 | |
| Date | 22th February 1938 | |
| -3- Let us now consider the benefits to be derived from the "Paulin" Bentley at speeds habitually used by the average Bentley owner, i.e., 70 M.P.H. and below:- (A) Firstly, let us assume that all the advantage gained is to be used in increasing the acceleration of the car, and express for simplicity this gain in acceleration in terms of equivalent weight reduction. If the full sized car lives up to the model, the following results will be obtained (Wind Tunnel report Da{Bernard Day - Chassis Design}/Evl/N.1.12.37.) The improved acceleration of the "Paulin" Bentley at the speed enumerated will be equivalent to reducing the weight of the standard Bentley by the following amounts:- Equivalent wt.saving Speed. Paulin Bentley. 40 M.P.H. 3.63 cwts. 50 " 6.10 " 60 " 11.10 " 70 " 26.10 " (B) Secondly, let us assume that all the advantage gained is to be devoted to saving fuel and in-creasing the life of the engine. The H.P. saved by the "Paulin" Bentley compared with the standard Bentley at the speeds enumerated will be as follows:- Reduction in H.P. to propel due to reduced Speed. windage of "Paulin Bentley." 40 M.P.H. 5.26 50 " 10.4 60 " 17.1 70 " 28.7 (C) In the above cases, no account has been taken of speeds above 70 M.P.H., whereas with the standard Bentley B.P. the "Paulin" Bentley will do over 110 M.P.H. In the third place let us assume that we do not want a top speed higher than 100 M.P.H. The engine characteristics can then be altered to give the maximum low speed torque at the expense of top H.P., and, in consequence, the acceleration from 10 M.P.H. increased by the amount of this improved torque, plus the amount gained from drag reduction. | ||