Caterham shrugs off Lotus's suggestion of illegal exhaust

Lotus technical director James Allison told reporters on the opening day of Jerez testing that the design of the Caterham exhaust could be illegal.

When asked for his comments on rival machinery, he said: "I have barely looked at anyone else's car, but I saw a detail on the Caterham's exhaust that I am not sure will survive until Melbourne..."

It is understood that the matter relates to a small piece of bodywork at the exit of the Caterham exhaust, which directs the airflow towards the floor.

Article 5.8.4 of F1's technical regulations states that no bodywork can be situated within a specified 'truncated' cone area, specified in detail below.

Caterham team principal Cyril Abiteboul believes that the piece of bodywork in question does lay outside of that restricted area, although he expects the matter to be subject to some discussion with the FIA and other teams.

"My understanding is that it is within the regulations," he told AUTOSPORT. "We tested it last year and nobody made any remark about it [then].

"We are quite flattered that James Allison is paying attention to what is happening at our exhausts. There are different ways of looking at it, and definitely we are outside of the cone."

Abiteboul said that Caterham would ensure it complied fully with the regulations, and that part of testing involved trialling new solutions on the cars that may not make it to the first race.

"The purpose of testing is to test and to understand what is happening. One of the areas that everybody is looking at is to understand how the exhaust effect is working, and where it is going.

"Therefore anything that helps you better measure that is welcome, at least for the tests. We will see whatever clarification is made before the first race."

What article 5.8.4 says:

5.8.4 Once the exhaust tailpipes, the bodywork required by Article 3.8.4 and any apertures permitted by Article 3.8.5 have been fully defined there must be no bodywork lying within a right circular truncated cone which:

a) Shares a common axis with that of the last 100mm of the tailpipe.

b) Has a forward diameter equal to that of each exhaust exit.

c) Starts at the exit of the tailpipe and extends rearwards as far as the rear wheel centre line.

d) Has a half-cone angle of 3° such that the cone has its larger diameter at the rear wheel centre line.

Furthermore, there must be a view from above, the side, or any intermediate angle perpendicular to the car centre line, from which the truncated cone is not obscured by any bodywork lying more than 50mm forward of the rear wheel centre line.

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