Being acquainted with Mike Costin and Keith Duckworth from his F2 days, Roy was able to secure the promise of Cosworth preparation for DFX engines, instead of the privateer US firms, and he planned to have major sponsorship in place for 1985. He also hoped to have no less a driver than Al Unser Jnr aboard.
With one eye on its Indy past (this would be 20 years after Clark upset Indy’s applecart), Lotus agreed to build the car. To familiarise himself with CART racing Ducarouge travelled to the USA to watch a race at Meadowlands, and returned with a copy of the rule book. Actual design, though, he passed to Martin Ogilvie and Gene Varnier.
“That was a bit of a con,” remembers Martin. “Gene and I wanted a payrise, and Peter Warr agreed, if we were prepared to do outside projects as well. We said yes, thinking there wasn’t likely to be an outside F1 project. Then Gerard dumped this Indycar on us!”
According to Ogilvie, ‘Duca’ gave them some specifications on a single sheet of paper and left them to get on with it, “It was a bit of a pain having to do this mid-season,” he says.
Varnier agrees: “We’d spend a week or two on the 96, then a week or two on the 97. It was a hell of a lot of work for a tiny design team. The worst thing was that it was deadly secret for the first couple of months – we were trying to investigate components without giving ourselves away.”
Things got easier when Autosport finally broke the story in June 1984. “Lotus to run two cars for whole CART season – including Indianapolis” was the banner headline, before speculating whether the team might use Renault turbo F1 engines, or even a Toyota V6 turbo which Lotus was rumoured to be investigating for F1. Warr hinted that Lotus had been considering Indy for a while, but “until now the chemistry was not right”.
This was not going to be a cheap project; Vernier remembers that the plan was for Winkelmann to pay up front. “It looked very expensive, but then he was getting a finished car, where the other teams got a chassis and had to do engine installation and final build.”
What emerged had a broad-shouldered beauty about it; and if it looked like a big 95T that wasn’t surprising. The monocoque was similar, but built much tougher because of the potential impact speed of concrete-walled oval racing. Where the F1 car used Nomex paper foil between its carbon/Kevlar skins, the IndyCar substituted an aluminium foil honeycomb, which is slightly stronger though harder to assemble. It also used a different, more fire-resistant phenolic resin.
Suspension at both ends was a wider version of the 95’s pullrod/wishbone set-up, beefed up to handle banking loads, while the aerodynamic package reflected CART practice with a low tail wing, deep-chord front aerofoils and the 95’s forward-slanting upper winglets.
According to Varnier, the aero tests used some clever technology. CART still allowed ground effects at this point, so the 96T had venturis in the sidepods. For wind tunnel testing, aerodynamics supremo John Davis built a large-scale model with a flexible venturi controlled by a series of stepper motors. This meant he could alter the profile remotely from the control booth, to home in on the best compromise between road and oval set-ups.