Table comparing Brake Horsepower (B.HP) and power loss for various exhaust system configurations at 3,500 R.P.M.
| Identifier | ExFiles\Box 8\8\ 08-page60 | |
| Date | 17th August 1938 guessed | |
| 3,500 R.P.M. B.H.P. LOSS. OPEN EXHAUST. 102.7 MANIFOLD ONLY. 99.7 3.0 MANIFOLD & FRONT EXP. BOX. 93.5 9.2 " " & INTER. BOX 91.7 11.0 " " without top hats & REAR SILENCER. 89.9 12.8 COMPLETE WRAITH EXHAUST SYSTEM WITH 1½" TAIL PIPE. 81.6 21.1 " " " " " 1¾" TAIL PIPE. 87.5 15.2 STRAIGHT THRO' 2" PIPE FROM MANIFOLD - TOTAL LENGTH 110". 95.8 6.9 FRONT EXP. BOX & 2" PIPE - TOTAL LENGTH 110". 91.7 11.0 STRAIGHT THRO' FRONT PIPE, INTER BOX, & STD. REAR SILENCER. 92.6 10.1 AS ABOVE WITH 1½" TAIL PIPE 86.5 16.2 " " " 1¾" TAIL PIPE 90.8 11.9 ** MANIFOLD & FRONT EXP. BOX top hats 45 holes & std. rear silencer. 89.9 12.8. | ||
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).