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).
Graph comparing engine power output (Brake Horse Power vs. RPM) using different diameter exhaust manifold pipes.
| Identifier | WestWitteringFiles\U\January1930-April1930\ Scan042 | |
| Date | 10th January 1930 | |
| COMPARISON OF MANIFOLD PIPES - EXHAUST SYSTEM TO N.SCH. 2931/2/47 (S.S.) THESE CURVES SHEW THE POWER OBTAINED WITH THE ABOVE EXHAUST SYSTEM, WHEN USING ① A 3.0" MANIFOLD PIPE (REDUCED TO 2.5" AT LOWER END), AND ② A 2.5" MANIFOLD PIPE. ENGINE Nō SS{S. Smith}-15 (STANDARD). CURVES CORRECTED TO N.T.P. BRAKE HORSE POWER R.P.M. OF ENGINE. CUT-OUT OPEN. 3.0" DIA PIPE. 2.5" DIA PIPE. CUT-OUT CLOSED. 3.0" DIA PIPE. 2.5" DIA PIPE. | ||