Brooklands performance test data for a 12 G IV Close Coupled Four Seater, comparing various car and engine configurations.
| Identifier | ExFiles\Box 5a\1\ 01-page200 | |
| Date | 14th August 1931 | |
| RM. {William Robotham - Chief Engineer} 28. 12 G IV BROOKLANDS TEST 14/8/31 CLOSE COUPLED FOUR SEATER WT. 32.25 CWT AXLE RATIO 11x50 TYRES 6" FORT DUNLOPS 19" RIMS. 60 MPH = 3000 RPM. CONDITION OF CAR AND UNIT | LAP TIME | LAP SPEED --- | --- | --- 1 CAR IN STANDARD T SERIES CONDITION BUT WITH STRONGER VALVE SPRINGS WHICH SHOULD HAVE NO EFFECT AT THIS SPEED | 2 MIN 31.4 SEC | 65.78 MPH 2 AS 1 BUT S.U. CARB | 2 MIN 26.4 SEC | 67.57 MPH 3 ENGINE GIVING 80 BHP AS IN CURVE RM {William Robotham - Chief Engineer} 27. STD CARB. CO. CLOSED P/ EX. SYSTEM | 2 MIN 17 SEC | 72.49 4 AS 3 BUT C.O. OPEN | 2 MIN 15.6 SEC | 73.45 5 ENGINE GIVING 89 B.H.P AS IN CURVE R.M.27 S.U. CARB. CO CLOSED | 2 MIN 12.4 SEC | 75.23 6 AS 5 BUT C.O. OPEN | 2 MIN 10 SEC | 76.62 AIR TEMP 19° C TOP WATER TEMP PLAIN BONNET 82° C " LOUVRED " 74° C PETROL CONS 160 MILES DERBY-BROOKLANDS RR CARB. 21 MPG S.U. CARB. 20.0 MPG 19 G IV 10,000 MILES CAR LAP SPEED 63.7 M.P.H Stamp Text: ROLLS-ROYCE LTD. ENGINEER'S OFFICE DRAWING No. 17 AUG 31 DERBY | ||
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).