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).
Letter to The Tubex Silencer Co. detailing performance figures for their exhaust silencer.
| Identifier | ExFiles\Box 152\3\ scan0176 | |
| Date | 18th March 1936 | |
| X1297 Exptl. Dept. Hs {Lord Ernest Hives - Chair} /Wym. {G. Harold Whyman - Experimental Manager} 20/KW. 18th March, 1936. Bernard Smith, Esq., The Tubex Silencer Co., 15, St. {Capt. P. R. Strong} Michaels Lane, Headingley, Leeds 6. Dear Sir, I can now give you some information concerning your exhaust silencer. I am afraid the tail pipe noise is considerably in excess of our own, but the figures for B.H.P. loss and back pressure might be helpful to you. At the peak of the power curve; i.e., 3500 R.P.M., the silencer alone loses 11 B.H.P., the new type fish tail loses an additional 11 B.H.P., and the old type fish tail an additional 17 B.H.P., therefore you have an exhaust system which loses 22 B.H.P. with one fish tail and 28 B.H.P. with the other. This again is a greater loss than on the R.R. silencer. With regard to back pressure, the silencer alone gives 19" Hg., with new type fish tail fitted 25" Hg., and old type fish tail fitted 36" Hg. Against these figures our own complete exhaust system only has a back pressure of 14" Hg. I wish to thank you for having given us the opportunity of trying your exhaust system on our cars, and in return I hope our figures and information will be helpful to you. Will you please let me know the address to which I can return your silencer and fishtails. Yours faithfully, FOR ROLLS-ROYCE LIMITED. | ||