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).
Data table from dynamometer tests on the Goshawk I engine, comparing theoretical and actual values.
| Identifier | ExFiles\Box 74\4\ scan0162 | |
| Date | 22th February 1921 | |
| GOSHAWK 1. DYNAMOMETER TESTS. | | Dyna. and drums. road wheel revs. | | Dynamometer Tachometer revs. | | | | ROAD SPEEDS. | | | | Engine revs. | Theoretical revs. | Actual revs. | Theoretical revs. | Actual revs. | Lbs. | HP. | Theoretical road speeds. | Theoretical road speeds taking wear of tyres into consideration. | Speedometer readings. | |---|---|---|---|---|---|---|---|---|---| | 500 | 82 | 82.5 | 328 | 330 | 85 | 9.97 | 11.71 | 11.57 | 14 | | 750 | 123 | 125 | 492 | 500 | 87 | 15.30 | 17.56 | 17.35 | 20 | | 1000 | 164 | 163.7 | 656 | 655 | 87 | 20.40 | 23.42 | 23.15 | 26 | | 1250 | 205 | 205 | 820 | 820 | 85 | 24.92 | 29.27 | 28.93 | 30 | | 1500 | 246 | 243.7 | 984 | 975 | 84 | 29.55 | 35.12 | 34.72 | 35 | | 1750 | 287 | 296.2 | 1148 | 1185 | 81 | 33.25 | 40.97 | 40.50 | 42 | | 2000 | 328 | 331.2 | 1312 | 1325 | 77 | 36.12 | 46.82 | 46.36 | 47 | | 2250 | 369 | 378.7 | 1476 | 1515 | 72 | 38.05 | 52.67 | 52.08 | 50 | | 2500 | 410 | 413.7 | 1640 | 1655 | 64 | 37.53 | 58.52 | 57.86 | 56 | | 2750 | 451 | 462.5 | 1804 | 1850 | 59 | 38.05 | 64.37 | 63.64 | 64 | | 3000 | 492 | 500 | 1968 | 2000 | 50 | 35.19 | 70.22 | 69.43 | 73 | | ||