A question of drag

Sir,

Having engaged my brain, as suggested by Keith Howard in Technofile (October 2000 issue), I have to disagree with his conclusion that substantial downforce is required only to improve cornering speed and has little relevance for practitioners of straight-line motorsport such as Land Speed Record-breaking and drag racing.

From their earliest days, both sports have always been blessed with more power than traction, and while many used old-fashioned weight to help the cause, a number of enlightened designers sought more elegant ways of solving the problem.

Drag racer Pete Robinson deserves to be mentioned alongside Chapman when reviewing the birth of ground effects. Like Chapman, he had a thing about weight, or rather, lack of it, and whenever he saw fellow competitors adding weight to improve traction, he was convinced there had to be a better way.

In 1968, he introduced a Top Fuel car with a chamber under the engine to manage air flow and, as he said, “make the tyres think the car weighs about a 10001bs pounds more than it does in reality.” A variety of designs ensued, concluding with a wedge-shaped rubber-skirted ground-effect device. It seemed to work too, immediately cutting times by two-tenths.

But unlike Peter Wright and Chapman, this brilliant intuitive engineer had no way of measuring the downforce he had induced and, on a qualifying run at the Pomona Wintemationals, something went wrong. The car turned sharp right into the guardrail, killing its designer-driver.

A photo taken just before the crash showed some extraordinary force pulling the car right and showed both front tyres leaving the rims.

The date? 1971, a full six years before Chapman began Formula One’s ground-effect revolution.

I am, Yours etc, Robin Richardson, Great Dunmow, Essex