Zaks Life Continued

Weight: The Pounds in the Right Place !

Racing cars derived from standard production cars and designed according to a conventional style (front engine and rear wheel drive) have always been at a great disadvantage. Based on the unfavourable weight distribution they could only be employed up to a power range that could easily be exceeded with the use of an exhaust-gas turbocharger. For this reason alone, the Turbo Capri (in view of it's engine) had to be designed so that it could be entered in the 2 litre maximum displacement division of the German National Production Car Championship. In as much as the maximum weight in this division was 735 kg, an equal amount of importance was attached to both the reduction and distribution of weight during the planning of the Turbo Capri.

The additional 100bhp that the turbocharged engine had compared to an induction engine made it necessary to cool the rear axle oil and transmission oil. And so, the engineers not only placed radiators for motor oil and water in the rear flared wings, but also added a radiator there to cool the four litres of oil needed to keep the transmission in good working order. The lubricant was conveyed along by two separate pumps. All other pieces of equipment that were not fastened to a permanent place were arranged right around the rear wheels. The former luggage area housed the battery, four electric fuel pumps, the storage tanks of the Halon fire extinguisher and the cylinder shaped tank of the dry sump lubrication system. The plastic safety tank (holding upto 100 litres of fuel) was situated in a metal housing in front of the rear axle.

The Cockpit: Functionalism Inside a Roll Cage

The interior of the Turbo Capri was at best spartan. The bucket seat, covered with fire resistant Nomex material was located inside a bare shell housing, made of aluminum piping, sheet metal and plastic. The drivers seat was positioned as far to the rear as possible in order to allow for the most advantageous distribution of weight. The small three-spoke leather steering wheel with a safety impact absorber, was adjustable as was the instrument unit attached to the steering column. The rest of the instrument panel, which was tilted towards the driver thus making it easier to see, contained a batch of instruments, automatic fuses and switches. Two additional hand wheels were located on the instrument board with which the driver could regulate both the distribution of brake power and the operating pressure of the turbocharger. In addition to the conveyor ducts for the engines lubricant and coolant (both of which originated in aircraft design) the wiring harness running through the vehicles interior had also been borrowed from the airplane industry. The use of a silver-wire cable, having a cross section of only 0.435mm resulted in a weight saving of more than 50% compared with standard cable.

The Body

The Turbo Capris body (as far as the bonnet, doors and flared wings were concerned) was composed of plastic. In the interests of obtaining the maximum weight reduction possible, Zakowski (as he had previously done with the Escort) did not employ the generally used fibre-glass soaked in polyester resin. The engineers chose instead an Aramid fibre called "Kevlar 49" this was distinguished not only by a high level of strength at low weight, but also by it's high price. For example a door made of this material cost about ten times more than a standard door, yet was 65% lighter. Also as a time saving measure, the wings were fastened to the car by means of quick-opening locks so that they could be removed in a hurry for maintenance work or repair. A further weight saving on the Capris body was accomplished in the window area. Apart from the front windscreen and the drivers window (which were required by the rules to be made of safety glass) all other windows, excluding the door glass, were glued on, thereby saving the weight of rubber frames and enhancing the rigidity of the body.

The design of the Capris body was developed on a 1.5 scale model, which Fords Racing Engineer, Thomas Ammerschlager, spent many hours testing in the wind tunnel at the Aachen University. The effort was worth it, the Turbo Capris lift factor was about 70% lower than that of the Racing Escort.