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).
Comparison of power losses in HP for different exhaust systems on the standard 40/50 model.
| Identifier | Morton\M7\ img049 | |
| Date | 1st April 1924 | |
| 1.4.24. POWER LOSSES TO EXHAUST SYSTEMS WITH THE W.W. AND DERBY SCHEMES ON THE STANDARD 40/50 The following figures give the loss in H.P. of the two schemes relative to the standard 40/50 system. The tests were taken with cut-out open. Table Data: Headers: R.P.M., H.P. with std. 40/50 R.R. exh. systems., Power loss relative to standard., W.W. exh. system. H.P., 'Derby' exh. system. H.P. Row 1: 2250, 89, 2.3, 1.6 Row 2: 2000, 84.4, 3.3, 1.7 Row 3: 1750, 83.9, 3.15, .6 Row 4: 1500, 74.6, 2.17, .7 Row 5: 1250, 64, 1.9, .5 Row 6: 1000, 51.2, .45, .3 Row 7: 750, 38.3, ---, .2 Row 8: 500, 25, .2, --- | ||