UNIPOWER GT

  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 once the cars had been driven on race tracks, (The first owner of Chassis 766.2, the first Competition GT spec car, had been 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 with 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 the problem in a wind-tunnel, to see what could be done to resolve this.

The benefit of fitting 'winglets' to the frontal side of cars, e.g. GT40, Lola etc... had been understood for a little while, however it was during this testing and purely by accident, that the positive effect of adding a frontal 'Air-dam' across the width of the car's nose was found to reduce lift by approx. 50% at 100 mph, but also to their surprise it also decreased its Drag coefficient from 0.37 to 0.32. This was revolutionary and would set the trend on all future cars of that period. Future car design would of course, mitigate the need to append an Air-dam to the cars nose, but the Unipower GT was the first car in Competition, to use this to great effect. It is interesting and as yet unexplained, why the Factory never fitted this revolutionary Air-dam to their production cars, leaving it to owners in subsequent years to modify their cars.

The following document, shows the original test sheet from MIRA at the time, showing the effect of fitting (they incorrectly called it a Spoiler, which is used to 'spoil' airflow to gain advantage) an Air-dam to the Unipower GT on the 26th September 1966.

Unipower Air-dam testing at MIRA.jpg
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