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).
Test report on a Phantom car (103-MC) with a modified exhaust system, assessing its sound and performance.
| Identifier | ExFiles\Box 71\3\ scan0305 | |
| Date | 31th August 1925 | |
| S/W (HS{Lord Ernest Hives - Chair}) K9950 GJ. c. to BJ. PH. H.{Arthur M. Hanbury - Head Complaints} Cx.{Major Len W. Cox - Advertising Manager} S/W (Hs{Lord Ernest Hives - Chair}) BK.{A. Birkett - Commercial Manager} CMB3/LH{Mr Haworth}31.8.25. CAR NO. 103-MC. OPEN TRIALS PHANTOM. (BARKER.) I gave this car a short test on the 30th August, as fitted by "S" with the modified exhaust system. When idling and when running quite slowly, I was unable to detect any difference between the sound from the exhaust now and previously, but, at any speeds above quite slow, there is a distinct improvement. There is also a complete absence of spitting and popping back from the exhaust when retarding. I was unable to judge whether there was any material alteration in the performance of the car due to the additional restriction on the exhaust, but I understand that Hs.{Lord Ernest Hives - Chair} obtained a speed of 70 m.p.h. on the London road, Derby, with this car. Even with the cut-out open the noise from the exhaust is rather subdued as compared with formerly, and it would appear that even in this condition there now is more restriction in the exhaust. Generally, whilst not accepting this as finality and subject to definite information regarding the difference in performance which may be expected, it is considered that this exhaust should be fitted in lieu of the at present standardised system. The front tyres of this car were pumped up to 55 lbs and the wheels had been balanced. Under these circumstances the front of the car rode somewhat hardly - not so much so as to be uncomfortable, but to an extent which will inevitably produce rattles round the front of any car in a very short time. It is, therefore, clear that | ||