[JimboJames1972]

Mike,

The four most common shells for circuit racing are the Lotus, Ascari, Mazda and the GT "Wedge".

The Mazda is aerodynamically the most balanced and safest shell when driven on the track. It's wide, flat windscreen, blunt nose and big wing push the aero grip well towards the rear to make it extremely neutral. It is a good all round shell, especially for beginners and club running but is not legal for Nationals.

The Lotus gives more front end aero grip. The windscreen is steeper and positioned further forwards so this gives a car that handles with more front end. It is significantly heavier than the Mazda though, and taller, and some think that this can promote more grip roll in certain conditions?

The Ascari is between the two. It has more aerodynamic grip than the Mazda and pushes this a little further forward too. However, is is also quite low and sleek and this is probably why it is popular on the circuits.

The "Wedge" is not commonly seen, although is is still legal for Nationals. It's aggressive front end shape means that positioning it on your shell exactly right is vital - too far forward gives a very front endy car, too far backwards gives understeer. Way back I had two of these shells that mounted just 5mm different to each other and the difference in grip was frightening!

The Ginetta is not legal, yet, but should get signed off next weekend at the AutoSport show. First testing though indicates its aerodynamic grip is towards the rear, more so than either the Mazda or Ascari. I'll drop you a line when I get some more test results through.

Hope this helps,

James