HINDSIGHT – 1971 LOLA T260 CANAM
Lessons learnt I
The low-drag Lola T260 had all the ingredients to be a winner but, plagued by handling and reliability issues, it struggled to fulfil its promise
n their time the cars that competed in the CanAm series were the most powerful road racing machines in the world. By 1971 the leading CanAm teams were using engines with displacements of more than 8.0-litres and generating peak power outputs in excess of 750bhp, with peak torque of over
650ft.lb. For its 1971 CanAm
programme, Lola Cars looked for a technical advantage that would allow it to leapfrog the McLaren team that had dominated the lucrative North American-based Sportscar series for the previous four years. The result was the Lola T260, a car based on low drag aerodynamic principles intended to give it a straight-line speed advantage without compromising its cornering capability.
DESIGN AND DEVELOPMENT Lola’s chief engineer in 1971 was Bob Marston, and he played a key role in the design and development of the new car, working closely with company founder and chief designer, Eric Broadley. The body shape concept for the T260 featured a short, rounded nose and abruptly truncated tail, with a stark, straight upper bodyline connecting the two. The low-drag approach was evident by the use of a minimal front splitter, while a full-width wing positioned just behind the engine intake stacks carried no end plates. A 25 per cent scale model of the T260 was soon testing down the street from the Lola factory at the Special Mouldings’ wind tunnel, where Peter Wright was the in-house aerodynamicist. ‘The small front splitter formed a lip around the leading edge of the
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www.racecar-engineering.com • February 2012 BY ALAN LIS
nose, but it was quite localised and didn’t really extend back more than a few inches,’ recalls Marston. ‘It wasn’t as effective as we had hoped because the wind tunnel tests showed that high pressure built up on the front of the chassis under the nose panel. So we came up with a plan to use the low-pressure area on the upper surface of the nose to pull the high pressure air out through ventilation holes and generate downforce at the stagnation point on the edge of the splitter and nose.’
Further tunnel tests showed
the ventilation holes to be worth pursuing, and they were
incorporated into the full scale car. ‘Of course, a wind tunnel only gives you answers to the questions that you ask,’ says Marston, ‘and in this case we didn’t know what were the right questions to ask. What a wind tunnel can’t tell you is how much downforce you can put on the tyres and how much downforce you need. ‘Like all motor racing wind
tunnels at that time, Specialised Mouldings’ wind tunnel didn’t have a rolling road and that’s a big factor when you are running a car close to the ground. We now know that is very important but, at that time, we didn’t have the experience necessary to realise. Like everyone in that era, we
Main picture: the perforated nose panel was a key element of the original low drag aerodynamic package. However, it proved to be far less effective on track than it had been in the wind tunnel
“a wind tunnel only gives you answers to the questions that you ask”
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