Posts Tagged ‘McLaren MP4/6 Honda’


Rainer Schlegelmilch’s artistry lays bare the clinical beauty of the 1991 McLaren Honda at Silverstone on 14 July…

Whilst this article is a summary of McLaren’s ultimately successful 1991 season of changing fortunes with its new Honda V12 powered McLaren MP4/6- all of the photographs are by Rainer Schlegelmilch and were taken over the Silverstone British GP weekend of 11 to 14 July.

This was Honda’s third different type of engine in four seasons- a new 3.5 litre 60˚ V12 unit with greater piston area than the outgoing V10 it replaced and therefore it had a potentially higher rev limit. More revs, all things being equal, results in more power. It was not without its chassis design and packaging issues, the motor was longer, heavier and thirstier than the V10 it replaced but the anticipated 720bhp should have been more than enough, on balance to make the car faster.

When first tested by Ayrton Senna in an MP4/6C test-mule, he was far from impressed and said as much to the Japanese. The Honda people persevered of course, and McLaren’s season got off to a great start with four wins on the trot. The increased engine weight was partially offset by the latest development of McLaren’s six-speed manual, transverse Weisman/McLaren gearbox.


Team led by Neil Oatley produced a handsome and effective brute in MP4/6


Whilst visually similar to the outgoing MP4/5B, the new cars aerodynamic profile was different as designer Neil Oatley and his team had received fresh perspective and input from Henri Durand who had jumped ship from Ferrari to McLaren in mid-1990.

Many changes had to be made to the chassis to accommodate the longer engine and enlarged fuel cell needed to satisfy its greater thirst. Despite additional length, the new tub was much stiffer in terms of torsional rigidity and comprised fewer basic components than its predecessors.

There were changes to the suspension too. The  pushrod-activated coil-spring/dampers were now mounted on top of the chassis ahead of the cockpit instead of being installed vertically on either side of the footwell.


The increased fuel consumption presented lots of challenges. Despite plenty of development on the engine management system, Senna twice ran out of fuel (at Silverstone and Hockenheim) but the Brazilian Ace and his new car remained unbeaten up to and including Monaco- giving McLaren a comfortable lead in the Constructors‘ Cup at that stage of the season.

This margin 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 threatening as the Williams FW14 Renault V10’s 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’ wrote McLaren.

Honda, of course continued development of its V12. The ‘Spec 1’, which won at Phoenix, Interlagos and Monaco was replaced by ‘Spec 2’- introduced ahead of Monaco offered better mid-range punch thanks to a new induction system. The friction problems were addressed in the ‘Spec 3’ variant here at Silverstone.

In addition the cars suspension was evolved, new linked rocker arms were fitted to reduce roll and a cockpit-adjustable ride-height mechanism was deployed.

The fuel metering issues so obvious during the British and German Grands Prix weekends were mainly caused by Shell’s experimentation with different fuel densities and viscosities.












At Silverstone Nigel Mansell and his Williams dominated at home, other than for part of the first lap- Senna jumped from grid 2 and led until Mansell passed him into Stowe, the Brit led from start to finish.

Nigel and Ayrton drove away from the rest leaving Berger, Prost and Alesi scrapping over third, a duel settled in Jean’s favour, he lost the place later in the race in a collision with Aguri Suzuki. Mansell won from Berger’s McLaren and Prost’s Ferrari 642 V12 with Senna classified fourth having lost his hard-raced second after running out of fuel, as written above.

Mansell gives Senna a lift back to the pits at the end of the British GP (R Schlegelmilch)

‘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 14,800 rpm, albeit only for short bursts’

In Budapest McLaren regained its form in order to able to save its season.

With great chassis balance and another reworked engine comprising lighter cylinder heads, camshafts and connecting rods, Senna pulled out some of the magic only he possessed and pushed the Williams FW14 Renault RS3 3.5 V10 duo back to second and third places.

Despite a ‘box failure he did it again at Spa where he nursed the failing car home and saw his lead over the Williams boys grow significantly after another Mansell retirement due to an electrical problem lost the Brit a ‘sure win’.


Engineers prepare two Honda RA121E V12’s for fitting into the cars of Senna and Berger

Then Williams had two wins- the Portuguese (Patrese) and Spanish GP’s (Mansell) in a season of changing fortunes, in Spain Senna struggled 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’.

An historic sidebar to MP4/6 is that it was the last car to win an F1 World Championship powered by a V12 engine and using a traditional manual gearbox. Whilst McLaren tested a semi-automatic ‘box during the season it was not deemed race-worthy so was not used, Williams and Ferrari were the only teams so equipped that season.

The 1992 championship winning Williams FW14B Renault was ‘an orgy of technology’- semi-automatic transmission, active suspension, traction control and for a while, anti-lock brakes whilst still using the evolved but tried and true Renault RS3/4 engines, a story for another time…







Rainer Schlegelmilch, Getty Images,





berger 1

Pole position and a win after waving teammate & champion elect AyrtonSenna into the lead…and having the favour returned late in the race giving Berger his first McLaren win…

Even though it was ‘only’ built in the ’60’s this Honda owned track must be one of todays classics, by any measure? Even though ‘130R’ has been ‘softened’ the track is still a formidable test of man and machine and on my circuit ‘bucket-list’. Its a non-‘Tilke Template’ track which is a positive.

Honda’s first V12 since the Surtees ‘Hondola’ Era…

Neil Oatley’s new chassis carried the Honda ‘RA121E’ 3.5 litre V12, replacing the previous very successful V10’s. The chassis was longer to accomodate a larger fuel cell for the thirstier V12 but still torsionally stiffer than its predecessor.Early testing by Berger and Ayrton Senna was not promising, they were unconvinced of the engines superiority over the V10… but the car still won its first 4 races in Senna’s hands.

engine honda

Honda ‘RA121-E’ ,3493cc, circa 720BHP @ 13000 rpm. McLaren MP4/6 Monaco 1991(Pinterest)

Williams FW14 & Mansell…

Williams FW14 then found mid season form and reliabilty. Adrian Newey , recruited from March where he created some stunning cars on small budgets was now deploying far greater resources well! He designed a superb car, the Williams Renault had a semi-automatic, 7 speed gearbox following the trail blazed by the Ferrari 640 the year before. It was regarded as a more advanced car, technically and aerodynamically than MP4/6, albeit the McLaren was more reliable and consistent.


Monaco 1991, Ayrton Senna 1st. McLaren MP4/6

Ongoing Development…

Honda focused on improving the engine management system and  frictional losses, introducing new heads, cams and rods, Honda’s ongoing development legendary! Oatley evolved aspects of the car as well incuding its sidepods and wings. Linked rocker arms to reduce roll, as well as a cockpit operated ride height adjustment meachanism were also created. All of the foregoing, as well as some reliability issues and misfortunes at Williams turned the tide back in McLaren’s favor, the car winning 8 Grands’ Prix and 10 poles.

McLaren took their fourth straight Constructors title and Senna his third, and last, Drivers Championship.

Demise of Manual ‘boxes & V12’s…

MP4/6was  the last Grand Prix car car with either a conventional manual ‘box or V12 engine to win a World Title…Oh, now,  for both manual ‘boxes and the mix of skill required, and punishment of mistakes made, and the race interest thus produced… let alone the sweet scream of V12 engines in the current F1!

front suspensio

MP4/6 Monaco…linked rocker arms were used later in the season to reduce roll and a cockpit activated ride height system…sheer artisrty isnt it?



Hold your breath…and remember these duels! Mansell & Senna , Williams FW14 Renault & McLren MP4/6, the 2 dominant cars of ’91. Mansell takes Senna for second…and later wins the race, Senna 5th. Spain, Catalunya, Barcelona sept ’91.

 The Previous Generation of Honda V12’s…


The previous generation of Honda V12’s…John Surtees in the Honda RA300, Mexican GP ’67, 4th. This car won the ’67 Italian GP in a last corner pass and dash to the flag, Surtees beating Jack’s Brabham BT24 Repco. The chassis was built by Lola , the T130, based on the successful Indy winning T90, hence the appelation at the time ‘Hondola’, Surtees having an enduring close association with Lola’s Eric Broadley.The ‘RA273’ engine was a 48 valve , 3 litre V12 producing circa 400 bhp. Honda’s 5 speed transaxle was also fitted. (The Cahier Archive)



Credits…, Pinterest,The Cahier Archive