I might be able to find my S6 info later but, the reality was about 1000bhp at take-off for the 1929 S6. Revs were low due to coarse prop and I believe they probably used up to full throttle to get some boost at this low rpm.
As an aside, Rolls Royce quickly realised the efficiency of high boost with low revs and second World War Merlin handling for long range cruise was throttle fully open but revs held down to 1700 with coarse prop via the speed governor.
Cheers
PS, For some great video of S6 etc, with sound! Search Youtube "1929 schneider trophy".
PPS, Just checked the data for the 1929 Rolls-Royce "R" engine, they were getting about 1100bhp at 2200rpm for take-off using a coarse race prop. I am sure that was with full throttle, boost not recorded but, I guess around zero-boost.
Last edited by Onceapilot; 10th January 2013 at 11:22.