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).
Brake pedal pressure distribution and mechanical efficiency for a system without front brakes.
| Identifier | ExFiles\Box 73\2\ scan0139 | |
| Date | 10th December 1923 | |
| R.R. 493A (40 H) (SL 42 12-7-23). J.H., D.{John DeLooze - Company Secretary} EXPERIMENTAL REPORT. Expl. No. 9940 REF: He/AB/LC10.12.23. EAC-111 BRAKE PEDAL PRESSURE DISTRIBUTION. (No front brakes only). Front brake equaliser (locked) Pressure distributor (connection to servo locked) W = Pressure applied to pedal connection on pressure distributor. w = Pressure available for distribution to both front brake cam operating levers i.e., pressure at end of each brake cam lever = w/2 for pressure W at pedal lever. Leverage on this car measured up and found to be as 1 : 1.45. i.e. W x 1 = w x 1.45. | W lbs. | w lbs. | Theor: (= W/1.45) | Loss of to friction. | Mech: effic: | |--------|--------|-----------------|--------------------|--------------| | 50 | 17 | 34.5 | 17.5 | 49.3% | | 75 | 35 | 51.7 | 16.7 | 67.6% | | 100 | 50 | 68.9 | 18.9 | 72.5% | | 125 | 60 | 86.2 | 26.2 | 69.6% | | 150 | 73 | 103.4 | 30.4 | 70.5% | | 175 | 87 | 120.7 | 33.7 | 72.1% | | 200 | 101 | 137.9 | 36.9 | 73.2% | | 225 | 115 | 155.4 | 40.1 | 74.0% | | 250 | 127 | 172.4 | 45.4 | 73.66% | | 275 | 120 | 189.6 | 69.6 | 63.3% | | 300 | 128 | 206.8 | 78.8 | 61.8% | | 325 | 143 | 224.1 | 81.1 | 63.8% | | 350 | 153 | 241.3 | 88.3 | 63.4% | Mechanical efficiency (average) = 67.3% | ||