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).
Testing of an independent front wheel suspension system and associated chassis rigidity improvements.
| Identifier | ExFiles\Box 154\1\ scan0081 | |
| Date | 14th November 1933 | |
| x8973 To Sg.{Arthur F. Sidgreaves - MD} } from E.{Mr Elliott - Chief Engineer} Nor. } c. Hs.{Lord Ernest Hives - Chair} Hy.{Tom Haldenby - Plant Engineer} Da.{Bernard Day - Chassis Design} K.5/HP.14.11.33. Independent Front Wheel Suspension. In testing the above system on 27-EX we must be prepared for results which as regards steering effects and front end oscillation may not be quite up to expectations realising as we do that the fore part of the frame on the P.2. chassis is more flexible torsionally than we should like. It is true that the stiffness of 27-EX frame will be enhanced by the attachment of the powerful tubular crossmember incorporated in the construction, and which contains the road springs, but the resulting rigidity is still below the degree of stiffness necessary to obtain the full realisation of the benefits of independent front wheel suspension. As the experiment proceeds we think it would be useful in this connection to couple up the four engine feet rigidly to the frame in such a way as to add in the torsional stiffness of the power unit with a view to obtaining by this temporary expedient a value for a more rigid construction. In the design of the SpectreCodename for Phantom III chassis we are devoting particular attention to this feature. The shorter length of the engine and its separation from the gearbox unit are instrumental in reducing the overhang of the frame in front of the body and in considerably shortening the gaping hole in the frame layout housing the power unit. Moreover the power unit itself is much shorter than the P.2. engine and the panel containing it is still further shortened by the incorporation of a cruciform member between engine and gearbox, the front connections of which reach well up into the engine bay and the rear to a straight crossmember carrying the tail of the gearbox. Furthermore we have arranged the side channels to be of box section and have extended box facings rigidly bolted to the large cross tube characteristic of the RR. engine suspension. This construction incidentally secures that the front wheel suspension assembly can be detached and dealt with as | ||