The BRM team cured their electrical coil trouble by mounting the unit on the left side of the engine instead of on the crash-bar stay as previously. They had four P160 models at the race, Gethin in 160/01, Siffert in 160/02 and Ganley in the brand-new 160/04, while 160/03 was using the latest engine with larger cylinder bores and shorter stroke. Siffert began practice with this car, but changed to the earlier one, which he used for the race. The aircraft-like air intake box was tried on 160/02 in practice, but discarded on the last day and for the race. Marko drove a 1970 car P153/07, which is not the car normally driven by Ganley, that being P153/06 which was still complete back at the factory.
Stewart’s Tyrrell 003 did the first two practice periods in long wheelbase form, this being achieved by inserting a large alloy distance piece between the engine and gearbox, thus moving the gearbox and the rear suspension some four inches further back. To achieve this a longer gearbox mainshaft was required, an extended clutch-operating mechanism, longer rear-wheel radius arms and longer mounting struts for the rear suspension sub-frame. The effect was not only to lengthen the wheelbase but also to alter the weight distribution and the polar-moments of inertia which are so critical to handling. On the last day of practice everything was put back to normal and it remained that way for the race and the results of the experiment seemed inconclusive. It is interesting that McLaren tried a similar experiment in private testing some while ago with equally inconclusive results. When the Hewland gear cluster is put in the space between the engine and the differential housing the results may prove more worthwhile. The second Tyrrell Team car was 002 running in normal form and the 001 was used briefly by Stewart as it has had no buyers since it was put on the market.
The Lotus team consisted of just the two latest Type 72 cars, Fittipaldi in the R5 as usual, and Wisell in R6, the sale of R3 to Dave Charlton’s South African team being rewarded with a win at Kyalami as soon as he got home (see “Around and About”).
Ferrari had the three 312B/2 cars, numbers 5, 6 and 7, Regazzoni used number 7 for the race, while Ickx retained number 6 which he regularly drives. Schenken and Hill were in their usual Brabham cars, the former having the full-width nose cowling on BT33/3, as tried experimentally at the Nurburgring. Of the March 711 cars, 711/1 had been converted to a Cosworth power unit and hired to Lauda, 711/2 was again being driven by Beuttler, 711/3 had been rebuilt completely, with a new monocoque and Pescarolo was driving it for Williams, 711/4 was driven again by Galli and 711/6 was Peterson’s car, Barber having taken 711/5 back to America.
As already explained, Surtees gave TS/001 to Stommelen and used TS9/004 himself, while TS9/002 was in the transporter as a spare. TS9/003 recently had a bad crash at Kyalami with John Love driving, but proved to be a very strong car. Hulme drove McLaren M19A/2 as usual and M19A/1 had been fitted with the rear suspension layout to the 1970 M14A pattern, for comparison tests, but the delay in arriving at the instant accident that Oliver had, ruined the whole plan. It was rebuilt for the race with new M14A parts for the rear end.—D. S. J.