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).
Comparative analysis of Packard suspension versus the Wraith suspension, focusing on weight and performance.
| Identifier | ExFiles\Box 127\2\ scan0070 | |
| Date | 31th March 1939 | |
| 1086 + 1305 Da{Bernard Day - Chassis Design}/Ev.{Ivan Evernden - coachwork} from Rm.{William Robotham - Chief Engineer} c. By.{R.W. Bailey - Chief Engineer} c. Da.{Bernard Day - Chassis Design} c. Da{Bernard Day - Chassis Design}/DB.{Donald Bastow - Suspensions} Rm{William Robotham - Chief Engineer}6/R.31.3.39. PACKARD SUSPENSION. We have read Da{Bernard Day - Chassis Design}/Ev{Ivan Evernden - coachwork}1/N.27.3.39. When setting out a specification for the rationalised car, we abandoned the front suspension invented by Rolls-Royce Ltd., because it was (1) too heavy (2) too costly (3) too noisy, and we could not appreciate that the customer got anything back in return for these disadvantages. We suggest that no one can dispute the accuracy of the three criticisms levelled at the Wraith suspension. Ev.{Ivan Evernden - coachwork} has enumerated a number of disadvan-tages which are alleged to apply to the Packard suspension. We are only interested in those which affect the customer, i.e. cost, weight or ability to function. We do not con-sider that the merit of a part should be assessed on its appearance, particularly if the owner cannot see it without lying under the chassis. Omitting, therefore, peculiarities that cause difficulties on the drawing board or to spring rating calculations, and considering the others we have - (1) The Packard pieces are heavy. The Packard suspension bits as will be seen from the attached weight analysis weigh 162 lbs 11 oz., the Wraith 237, i.e., the Wraith bits are 46% heavier than those of the rationalised chassis. As the bits on B.V. are in cast steel and have completed 46,000 miles without trouble, it is obvious that we can lighten them and this is being done on the "Corniche". Additionally, we can make the shock absorber in aluminium as on the Wraith. Therefore, if the "Packard" bits are too heavy, what can be said for the Wraith pieces. (2) Insufficient Wheel Movement. We have got the best ride on B.V. that we have ever had. The Silver Wraith seems equally good. | ||