The McLaren team bought out a third variation of the M28, this one being built around the monocoque of M28/3 and in view of the many changes made it was given the suffix C. Somebody had obviously been looking closely at the Lotus 80, even though it has yet to prove to be the way to go. The M28C had a longer and slimmer nose cowling, mounted on a pair of plates cantilevered from the front bulkhead; all the suspension pick-up points on the front suspension were moved into the monocoque and the suspension members were re-profiled to present a much tidier front end for the air to flow through on its way to the radiator intakes and under the side-pods. The B-version which was built around M28/2 and which Watson drove in the Belgian GP was handed down to Tambay, while the Ulsterman had the improved M28/3C.
Renault came up with a second RS10 car, this brand new one being for Jabouille, while Arnoux took over the original RS10 that Jabouille had used at the Belgian GP. Both cars were fitted with the new twin-turbo-charger layout and it looked a very much better installation than the single unit used previously. There is a completely separate layout on each side of the V6 engine, the only connection being the throttle cables and various pressure and balance pipes. Each bank of three cylinders exhausts into a turbo-charger mounted to the side and to the rear of the engine. The exhaust pipe from each turbo-charger then turns inwards and then backwards across the top of the gearbox, ending in a megaphone. The “waste-gate” or pressure release valve for each turbo-charger is mounted to the rear of the unit and its exhaust pipe follows the engine exhaust over the gearbox, ending in a small megaphone so that from the rear you see four exhaust pipes; two large ones from the engine and two small ones from the waste-gates. The air compressor of each turbo unit is mounted to the outside of the turbine, drawing in air axially from a sunken duct in the side of the car just ahead of the rear wheel on each side. The radial outlet from each compressor feeds forwards into its own inter-cooler, which is coupled into the main water-cooling system, and then feeds up the front of the engine into a tubular manifold for the three cylinders on each side. Although this twin-turbo layout must weigh a bit more than the single one, it does mean that the turbines need not run quite so close to the heat limit, and the twin layout gives better initial response and better pick-up from low speed.
The Shadow car that de Angelis damaged at Zolder was rebuilt around a new monocoque “tub” and the Ensign MN09 re-appeared with revised radiators, revised suspension geometry and improved bodywork. The Ligier team repaired JS11/03 which Depailler damaged in practice at Zolder, and abandoned JS11/01 which he damaged in te race. In its place they completed a new car, JS11/04 to the same specification and it was the spare for the team at Monaco. All the cars had been fitted with different air-deflectors in front of the rear wheels and a different form of rear aerofoil. During pre-race days the Williams team completed a third FW07, which Alan Jones used after damaging the monocoque of his original car.
Apart from detail changes, like improved air scoops on the sides of the Lotus 80, to feed air to the rear brakes, and both Ferraris using the forward-mounted rear aerofoil first seen at Long Beach, everything was much as before. – D.S.J.