• The legality of Brabham’s 1983 World Championship

    A couple of recent pieces in the motorsport press have raised separate issues over the legality of the Brabham-BMW which won the 1983 World Drivers’ Championship in the hands of Nelson Piquet. Gary Watkins’s Autosport article re-considered the exotic, ex-Luftwaffe fuel brew used by BMW in the latter stages of the season, while Mike Doodson’s Motorsport article elicited the following admission from then-Chief Mechanic Charlie Whiting that, “All I will say is that we always, um, attempted to make the car as light as possible.”

    Indeed, and not just in qualifying it seems, for Gordon Murray rather gave the game away earlier this year with the following comment:

    “Whenever we planned to stop – we could go without on street circuits – we tended to do 60-70 per cent of the race on the first set of tyres because that meant we could run very close to, or under, the minimum limit before adjusting the weight with the amount of fuel we put in,” (Motorsport, May 2013, p86).

    That’s a pretty unambiguous admission that the Brabhams ran under the legal weight limit in many 1983 Grands Prix, and used fuel-weight as ballast. If you go through the races in 1983 you’ll see that Piquet’s Brabham was almost always the last of the leading runners to pit for fuel, and that he sometimes pitted 5-10 laps or so after the Ferraris and Renaults, his championship competitors. At Hockenheim, for example, Prost’s Renault stopped on lap 20, while Piquet stopped on lap 30.

    Why would Brabham want to stop after everyone else? Well, in the era of refuelling, a car on empty tanks and worn tyres was generally faster than a car which was fuelled-up on fresh tyres. Moreover, in 1983 the Ferraris were shod with bias-ply Goodyear tyres, and thereby tended to suffer greater tyre warm-up difficulties than the Michelin-tyred Brabham. Thus, it was in this 5-10 lap window that the Brabham would often make hay.

    At Spa, Tambay’s Ferrari was running ahead of Piquet until stopping on lap 21; Piquet stopped on lap 24, and jumped ahead of the Ferrari, forcing Tambay to re-pass some laps later. Similarly, at the Osterreichring, leader Arnoux’s Ferrari stopped on lap 28, Piquet on lap 31, after which Piquet emerged ahead, forcing Arnoux to re-pass some laps later.

    So why, then, wouldn’t everyone schedule their pit-stops at 3/4 distance? Well, that extra fuel-weight costs lap-time, and it costs you lap-time on each and every lap that you carry the extra weight around on your back. If you started a race with about 20kg of extra fuel, that would cost you about 0.6seconds of lap-time, which over 30 laps would mount up to a very substantial 18 seconds or so.

    However, if your car was 20kg beneath the legal weight limit when drained of fuel, you could start the race at the same weight as your competitors, but with the ability to run 5 laps or so further. You would suffer no disadvantage in the early stages of the race, and you would also be able to jump ahead of your competitors by running longer. Perfect.

    In fact, just about the only time Piquet didn’t run long was in the final race at Kyalami, when he shot off into the distance on a light fuel load, pitting on lap 28 of 77, able to resume without having lost the lead. It’s possible that the Brabham started the race over the legal weight limit, but was running underweight for a significant portion of this stint. Moreover, in the late stages of the race Piquet slowed considerably, sacrificing what appeared to be an easy victory. Contrary to the explanation given on the day, that Piquet was merely trying to ensure the reliability of his car, he might also have been minimising fuel consumption to ensure the car was actually over the legal weight limit at the end of the race!

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  • Lorenzo keeps championship hopes alive with victory in Japan

    Jorge Lorenzo sealed a masterful victory at today’s AirAsia Grand Prix of Japan with the Yamaha Factory Racing rider pushing to the limit to stay ahead of main championship rival Marc Marquez at the Twin Ring Motegi circuit with Repsol Honda teammate Dani Pedrosa securing another podium finish to the delight of the Japanese fans.

    To take this win at the home of Honda makes me very … Keep reading

    Special thanks to: motorsport.com

  • Ferrari’s illegal brake ducts

    When Ferrari launched their 1976 car, the 312T2, it appeared with a pair of outrageous front brake-duct appendages. These extended forwards, and curved around the inner front shoulder of the tyres, presumably with the intention of reducing front-wheel drag and turbulence.

    These brake-duct extensions appeared only once during the racing season, in modified form, at the French Grand Prix (above). Pete Lyons reported in Autosport/Autocourse that “As a member of the CSI [the sport’s governing body], Jabby Crombac pointed out that these appeared to contravene the regulations about ‘movable aerodynamic devices’ and the first session times for both cars were disallowed.”

    Note that these brake ducts were declared illegal, not because they intruded into a region from which bodywork was prohibited, but because they constituted movable aerodynamic devices. That is to say, being attached to the wheel uprights, they moved with respect to the sprung mass of the car, the reference frame against which movability is judged in this context.

    It is a curiosity, then, that despite this precedent, and despite the fact that section 3.15 of the current Formula One Technical Regulations still requires bodywork influencing the aerodynamics to be “immobile in relation to the sprung part of the car,” brake ducts are explicitly exempted. Devices such as those pictured below seem not dissimilar to those on the 312T2 at Paul Ricard in 1976. Perhaps Ferrari should ask for their Friday morning times to be reinstated…

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  • Yonny Hernandez finishes Australian GP in 13th position

    Thanks in part to a good start that enabled him to immediately advance two positions, Yonny Hernandez concluded the exciting sixteenth round of the MotoGP World Championship, hosted at Phillip Island Circuit, with a thirteenth place finish. Along the way, he recorded a 1’30.825 lap time that was his best of the Australian weekend.
    Keep reading

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  • Bridgestone: Malaysian debrief with Masao Azuma

    After unsettled weather on Friday and Saturday, conditions on race day were warm and fine with the track temperature reaching 46°C at the start of the race. Softer slicks front and rear were preferred by the twenty-three riders contesting the Malaysian Grand Prix, with only two riders selecting the harder rear slick option, and just five riders opting for the hard compound front tyre … Keep reading

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