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).
Performance benefits of running a Duplex Exhaust System on the 'Corniche'.
| Identifier | ExFiles\Box 97\3\ scan0263 | |
| Date | 30th June 1939 | |
| H50C. By.{R.W. Bailey - Chief Engineer} from Rm.{William Robotham - Chief Engineer} c. Da.{Bernard Day - Chassis Design} Rm{William Robotham - Chief Engineer}9/R.30.6.39. 'CORNICHE' EXHAUST SYSTEM. We have been running the Duplex Exhaust System on the 'Corniche'. The attached power curve shows what we got out of it. This is actually worth about 2 m.p.h. in actual lap speed, but will be worth more than this under favourable road conditions. As will be seen from the attached curves it is worth 7% increase in road horse-power @ 3,000, whereas the increase in weight is 18 lbs only, or ½%. The big advantage of the Duplex Exhaust System over the cutout is that the customer gets the benefit of it under ordinary touring conditions. We agree that its complications would not be justified for a standard car, but there are so few things that we can do to the Corniche to improve its performance that we think it is well worth while in this particular case. The work done will not be wasted since the Duplex Exhaust System will give better results when used on the cast iron unit where the manifold is divided into two entirely separate halves. Rm.{William Robotham - Chief Engineer} | ||