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).
Table comparing lap speeds in M.P.H. for various carburettor and air silencer test configurations.
| Identifier | WestWitteringFiles\U\August1930-November1930\ Scan145 | |
| Date | 26th October 1930 | |
| -3- Hs{Lord Ernest Hives - Chair}/JL.1/AL.26.10.30.Contd. CONDITION OF TESTS. LAP SPEED M.P.H ------------------- --------------- Complete Silenced Carburetter. 77.5 Standard Carburetter (off 19-EX.). 78.43 Silenced Carburetter with air silencer off complete. 78.85 Air Silencer with outer baffle tube (E.80228) taken off. 77.7 Air Silencer with 2nd. baffle tube (E.80229) taken off. 77.7 Air Silencer with 3rd. baffle tube (E.80230) taken off. 78.43 Air Silencer with middle baffle tube (E.80227) and gauze taken off. 78.1 Top and bottom castings of air silencer on only (no tubular baffles at all). 78.85 Two outer baffle tubes replaced by 'air maze'. air valve relief holes blanked up. 77.9 Complete Air Silenced Carburetter with Bonnet off. 78.1 The loss in maximum speed on this car was only .9 M.P.H. due to fitting the air silenced carburetter. The two outer tubes do not absorb very much power ;- .2 M.P.H.; the 3rd. tube absorbs .9 M.P.H., and the inner tube .6 M.P.H.; actually this carburetter with no air silencer at all is .42 M.P.H. faster than the standard carburetter. | ||