The COAT - Round One - McLaren MP4/6 vs Lotus 25

[crmalcolm]

And we now have the thrity-second, and final, match in Round One. If your favourite F1 car has not made the list, the chance has passed.
For this last match, we have the McLaren MP4/6 up against the Lotus 25.

McLaren MP4/6 (mclaren.com):
This was Honda's third engine configuration in just four seasons, and was an entirely new 60? unit with a greater piston area than the outgoing engine and a potentially higher rev limit. It was longer, heavier and thirstier than the V10, but it was hoped that an output reputed to be 720bhp would compensate for that. However, the engine installed in the MP4/5C test mule failed to convince Senna. Concerned that it simply wouldn't be sufficient to defeat Renault's new, improved V10, he was quick to tell the Japanese what he thought of it in his usual candid terms.

Though naturally concerned to hear this, the Japanese stuck to their guns, Akimasa Yasuoka arguing that, "Honda traditionally detunes its engines for the first race of the season; we tend to go for reliability rather than power." In retrospect, it was perhaps right to do so for McLaren's season got off to the best possible start with no fewer than four wins in a row, the increased engine weight partly offset by the latest development of McLaren's six-speed gearbox.

The car itself, whilst looking similar to MP4/5B, was quite different in terms of its aerodynamic profile as designer Neil Oatley and his team had received some valuable input from Henri Durand who had joined from Ferrari in mid-1990.

Numerous changes had also to be made to the chassis, not least in order to accommodate the longer engine and the enlarged fuel cell needed to satisfy its greater thirst. Even with four centimetres added to its length the new tub was much stiffer in terms of torsional rigidity, and consisted of even fewer basic components than before. There were changes to the suspension too, an aspect of the car which had altered dramatically since the year before, with pushrod-activated coil-spring/dampers now mounted on top of the chassis ahead of the cockpit instead of being installed vertically either side of the footwell.

The increased fuel consumption posed challenges of its own, despite plenty of development on the engine management system, Senna twice ran out of fuel (at Silverstone and Hockenheim) but the Brazilian and his MP4/6 nevertheless remained unbeaten up to and including Monaco. Giving McLaren a comfortable lead in the Constructors‘ Cup, the margin thus gained was to prove crucially important as the team's performance began to slip and Williams-Renault began to gather pace with Nigel Mansell and Riccardo Patrese as its reliability improved.

In Montreal two things quickly became apparent. The first was that the Honda's extra power was simply to offset its greater weight relative to the V10s, particularly when its internal frictional losses continued to rise. The other was that the Williams FW14s, particularly Mansell's, were really getting into their stride.

Undeterred, Honda continued developing its V12. The Spec 1, which had triumphed at Phoenix, Interlagos and in the Principality, eventually gave way to a Spec 2 variant which was actually introduced ahead of the Monaco circuit and offered better mid-range punch thanks to its new induction system. The friction problems were also addressed with a Spec 3 version at Silverstone. New linked rocker arms were also employed in a bid to reduce roll, and a cockpit-adjustable ride-height mechanism was also added.

The fuel metering issues that made themselves so painfully felt during the British and German rounds were largely to do with Shell's experimentation with different fuel densities and viscosities. At Paul Ricard, another inaccurate readout forced Senna to drive conservatively, although following this Honda's research and development effort accelerated dramatically so that by the time he arrived in Hungary he had a car which could be safely revved to 14,800Grpm, albeit only for short bursts.

In Budapest McLaren regained its form in the nick of time. With a tighter-than-ever chassis, and yet another heavily reworked engine with lighter cylinder heads, camshafts and connecting rods, Senna pulled something out of the bag and pushed the Williams duo back to second and third places.

Despite suffering a gearbox failure, he managed it again at Spa for the Belgian Grand Prix, where he nursed his failing car home and saw his lead over Williams grow enormously following another retirement by Mansell. McLaren’s rival was quickly restored to good fortune, however, commanding the field in both the Portuguese and Spanish races, the last of which saw Senna struggling on the wrong tyres.

At Suzuka the order flipped again, the correct tyres and yet more successful engine development leaving Senna in an unassailable position on 96 points. He returned to Brazil with a resounding third title, while Berger finished fourth with 43 points, having been handed victory by Senna in Suzuka. McLaren again took the Constructors World Championship.

Lotus 25 (grandprixhistory.org):
In 1961 the engine capacity for Formula 1 was reduced to 1.5 liters. Engines also need to run on 101.5 octane fuel instead of the 130 octane Avgas. The first year of the new regulations found all of the British teams down on power compared to Ferrari with the expected results. For 1962 Lotus would answer with the Lotus 25. Mid-engined cars were now standard and the Lotus 25 was not the first racing car with a monocoque chassis but its artistic simplicity and immense success in the hands of Jimmy Clark revolutionized Grand Prix racing car design. Monocoque construction had been used in aeronautical engineering for over 50 years. In 1915 Harry Blood campaigned a metal-fuselaged Carnelian at Indianapolis. Gabriel Voisin used a monocoque chassis for his car that he raced in the 1923 French GP and in 1955 BRM incorporated a semi-monocoque chassis in their Grand Prix cars.

Colin Chapman had experimented with a backbone chassis for the Lotus Elan sports car. He decided to apply the same techniques to a single-seater racing car. By using box-sections he created a tub just wide enough for a driver and within the box-section would go rubber bags to hold the fuel. While this was going on there was also a Type 24 being developed using a spaceframe just in case. As part of the design the drive would now sit in an almost reclining position that took some use to, and it took a brave man indeed to drive one of these cars at full speed. The main benefits of this design were increased torsional rigidity for lees weight and with a smaller frontal area. The resulting stiffness allowed Lotus to use more supple suspension which offered great advantages in slower, tighter turns. Colin Chapman was known as an instinctive seat of the pants designer. In fact when the first prototype was being built he took the opportunity of sitting in the car. To his surprise he found that he could fit quite comfortably and announced forthright that: "This cockpit's too wide ... take another inch and a half out out of it!" Dick Scammell, one of the mechanics that built the first car would later remark that: "None of us really knew what we were doing, but it all took shape very nicely and it certainly looked right."

Power was again provided by Coventry-Climax, the British forklift, fire pump, racing, and other speciality engine manufacturer. At £3000 per motor they hoped that Ferrari's engine advantage would be bridged. The car was fast straight out of the box and with Clark driving, when it finished it usually won. In 1963, Engineer Len Terry was coaxed in to returning to the team that had fired him in 1959. One of his duties was to improve the car's reliability. His work bore fruit when Scotsman Jim Clark after finishing 8th in Monaco won the next four races in a row. Clark would go on to win a then record seven out of ten races and his first World Championship. Graham Hill and Richie Ginther finished 2nd and 3rd respectively.

[Aysedasi]

Heck, that's a tough call. Somewhat against my normal 'emotional' judgement, I'll give this one to Lotus.

[crmalcolm]

Originally Posted by Aysedasi

Heck, that's a tough call. Somewhat against my normal 'emotional' judgement, I'll give this one to Lotus.

I had a feeling this one would be tough for you as I was drafting the post.

[Gerard C]

Hey, we've been asking for good ol'cars, here is one so… Lotus for me!

[S griffin]

The MP4/6. Very underrated car, and definitely an underrated title for Senna too

[Aysedasi]

Originally Posted by crmalcolm

I had a feeling this one would be tough for you as I was drafting the post.

You know me too well!