Balance of power

It was a decade of staggering power peaks followed by fierce rule changes to cut speeds; despite that, lap times soon began to fall again

Words: Mark Hughes. Photography: LAT

1985 Lotus 97T

Index figure: 224.9

Virtual lap time of the current Spa circuit: 1m 54.2s 

A refinement of the Renault turbo V6-powered 94/95Ts of the previous years, with Ayrton Senna now at the wheel for some explosive qualifying. A modified EF15 engine allowed more qualifying boost than the TAG-Porsche, topping 1000bhp. But, unable to match the McLaren’s fuel efficiency, it raced with lower boost; it was aerodynamically less advanced too. 

1986 Lotus 98T

Index figure: 226.9

Virtual lap time of the current Spa circuit: 1m 52.1s

More of the same for Lotus. Still not aerodynamically cutting-edge, but with 1400 qualifying horsepower and Senna driving, it set eight poles. It lost out in races to Williams-Hondas on aerodynamic and fuel; in race trim it was able to run only around 840bhp, as much as 80bhp down on the Honda. 

1987 Williams FW11B

Index figure: 227.1

Virtual lap time of the current Spa circuit: 1m 51.9s 

Turbo boost was theoretically restricted to four bar via pop-off valves, but there was a way around this on self-contained V6s like the Honda. They required just one pop-off valve (as opposed to those like the Porsche and Ford which effectively ran as two separate three-cylinder units and so needed two pop-off valves) by overboosting, forcing the pop-off to open and then controlling it against boost. It meant 900bhp in races, 1050bhp in qualifying. This and the aero efficiency of the Williams made it the dominant car. It won in both conventional and active ride forms. A Goodyear monopoly meant hard tyre compounds.

1988 McLaren MP4/4

Index figure: 225.6

Virtual lap time of the current Spa circuit: 1m 53.5s 

The boost restriction was a more severe two and a half bar, and the fuel allowance was cut to a swingeing 150 litres, meaning a big reduction in power (with Honda racing at between 610-700bhp during the year). Honda switched its supply from Williams to McLaren and the Gordon Murray/Steve Nichols MP4/4 made devastating use of the new low-line V6s, with a lay-down cockpit layout as previously used on Murray’s Brabham BT55. It won all but one race. 

1989 McLaren MP4/5

Index figure: 227.8

Virtual lap time of the current Spa circuit: 1m 51.2s 

A new formula that banned turbos and stipulated a normally aspirated 3.5-litre motor meant horsepower similar to that seen in the final year of the restricted turbos. McLaren designed its MP4/5 around a new Honda 72-deg V10. Like Renault, Honda had arrived at the conclusion of a 10 being the perfect compromise between V8 packaging and fuel efficiency and V12 power. Despite an aerodynamic imbalance, Senna and Prost were again able to fight each other and beat all the others. Minimum weight reduced from 540 to 500kg.

1990 McLaren MP4/5B

Index figure: 229.4

Virtual lap time of the current Spa circuit: 1m 49.5s 

A revision of the ’89 car with a further evolution of the Honda V10 now good for around 690bhp at 13,200rpm in race trim, impressively higher than that year’s Ferrari V12. Pirelli’s re-entry restarted the tyre war, bringing softer compounds worth more than one second per lap.

1991 McLaren MP4/6

Index figure: 231.2

Virtual lap time of the current Spa circuit: 1m 47.7s

Honda opted to replace its V10 with a V12, boosting power to 780bhp at 14,800rpm by year’s end, but adding a weight, cooling and fuel consumption penalty. The new chassis featured horizontal spring/dampers above the chassis, like Ferrari, but it wasn’t until late season that it featured the semi-automatic paddle gearchange that had been on the Ferrari since 1989.  

1992 Williams FW14B

Index figure: 231.2

Virtual lap time of the current Spa circuit: 1m 47.7s

Adrian Newey and Patrick Head added active ride to last year’s Renault V10-powered FW14. This time the electronics were up to optimising the car’s aerodynamics at all times. It gave them a massive advantage, and Nigel Mansell reeled off a dominant world championship. An end to the tyre war meant that the FW14B was no faster than the previous year’s best – even though it was up to two seconds faster than the opposition.

1993 Williams FW15C

Index figure: 231.7

Virtual lap time of the current Spa circuit: 1m 47.1s 

Narrower rear tyres and front track and raised front wing endplates were imposed to control speeds, but traction control and automatic upchanging more than overcame these penalties. The FW15C, a direct derivative of the 14B, still using active, was an edgier, more responsive car. From France on it raced with ABS, but didn’t get the cockpit bargeboards pioneered by McLaren that directed air more efficiently over body surfaces.

1994 Benetton B194

Index figure: 230.5

Virtual lap time of the current Spa circuit: 1m 48.4s

With fuel stops permitted for the first time in 11 years, fuel tanks were made much smaller, enhancing aerodynamics. On the other side of the coin, traction control, ABS and power braking were all banned. Following the Imola tragedies further restrictions were imposed: engine airboxes were made smaller, minimum weight was increased from 500 to 515kg and in the second half of the season there was an underbody plank to enforce a minimum ride height. The Cosworth V8-powered Benetton B194, designed by Rory Byrne, caused controversy car after it was found capable of the banned launch and traction control. In Michael Schumacher’s hands, it was by a narrow margin a faster qualifying car than the rival Williams-Renault. 

1995 Williams FW17

Index figure: 228.2

Virtual lap time of the current Spa circuit: 1m 50.8s 

Engine size was reduced from 3.5 to 3 litres, the minimum weight was stipulated at 600kg including the driver (effectively making the cars around 15kg heavier), the chemical make-up of the fuel was more tightly defined, a 50mm step in the floor further limited ground effect and wings were reduced in size. It all conspired to slow the cars by around 2.4sec per lap. The latest iteration of Adrian Newey’s Williams powered by Jean-Jacques His’ Renault V10 was the fastest car in the field, but beaten to the title by the similarly powered Benetton of Michael Schumacher. It featured a Benetton-style raised nose to enhance airflow over the front wings, and torsion bar front suspension.