Groundbreaking Aerodynamic Developments
It has been previously mentioned that the Unipower GT design in respect to its body shape, was the result of a collaboration with Ron Bradshaw, who had been working on the Ford GT40 project. As is the case with many car designs, what the designer would like and what is needed to make the design function in the real world, are often quite different.
It is one such element, that of the frontal body shape, that came under scrutiny predominantly once the cars had been driven on race tracks, (The owner of Chassis 766.2, being the first Competition spec car, was experiencing various problems which Ernie Unger and Val Dare-Bryan worked to resolve) when the much higher speeds exposed a stability issue, caused by the front end lifting at speed giving a worrying lack of steering feel. This had also been apparent on the road-cars at speeds approaching 100mph (the Author had experienced this vagueness of steering even with his 998cc car, made worse when fitted with a 1275 'S' unit). It was considered that changing the shape of the nose was going to create some major problems, with headlight height and the general packaging of the components in that area, so in September of 1966, the Factory took a scale model to the MIRA (Motor Industry Research Association) in Nuneaton, England to simulate in a wind-tunnel, what/where the issue was and what might be done to resolve this.
It had been understood for a little while, the benefit of fitting 'winglets' to the frontal side of cars, e.g. GT40, Lola etc..., however it was during the testing and purely by accident, that the positive effect of adding a frontal 'spoiler' across the width of the car's nose was realised to reduce lift (increase down-force). This was a revolutionary and would set the trend on all future cars of that period, that experienced this lack of down-force. Future car design would of course, mitigate the need to append a spoiler to the cars nose, but the Unipower GT was the first car in Competition to use this to great effect. It should be noted however that the Factory never fitted a spolier to the production cars, leaving it to owners in subsequent years to modify their cars, the most popular component to be fitted being the VW Golf Mk1 front spoiler, being both cheap and fitted the nose perfectly without any modification.
The following document, is the original test sheet from MIRA, showing the effect of fitting a spoiler to the Unipower GT on the 26th September 1966. It can be seen that the fitting of the Spoiler reduced lift on the front by about 50% at 100mph with even greater benefits as speed increased.
© Gerry Hulford
© Val Dare-Bryan