Benetton's Side of 1994: Driving Aids

How the team from Enstone responded to the allegations of using driving aids.

This year marks the 30th anniversary of the 1994 Formula 1 Championship, a season marred by death, accidents and controversies surrounding Benetton and their star driver, Michael Schumacher. Allegations of using illegal driving aids, a two-race ban for ignoring the black flag, the disqualification for excessive plank wear – the team from Enstone had a lot to deal with and answer to in 1994.

There are two sides to every story, as the old cliché goes. The purpose of this post, the first in the series, is to present Benetton’s perspective and provide additional context.

Traction Control

Ayrton Senna, while observing the cars from the sidelines of the Aida circuit, noticed that the Benettons misfired in slow corners. The Brazilian suspected they were using traction control, which had been banned by the FIA at the end of 1993. And here is where the controversy started.

Did Benetton have it? No, if you’re asking about the means, but somewhat yes if you’re asking about the ends. Let me explain.

Traction control is an electronic system designed to prevent wheel spin during acceleration. In simple terms, a sensor detects when a wheel is losing grip and spinning excessively. The system then reduces engine power to that wheel. Benetton did not have it.

The FIA hired a company named LDRA Ltd. to investigate the electronic systems of the teams, and they discovered a hidden code for launch control in the software of the Benetton B194. No traction control was found.

According to Willem Toet, who was the Head of Aerodynamics at Benetton at the time, they were doing something different, something that allowed them to achieve effects similar to traction control, all while remaining compliant with the rule book.

Back then, in the early 1990s it wasn’t uncommon to see half of the grid retire due to reliability issues. To increase the reliability of power units, the rules allowed the teams to limit the rate of acceleration of their engines. Benetton used it to their advantage. How they did it? Willem Toet explains:

So engines were permitted to sense atmospheric pressure and hence you had all you needed to modify the limit rate of acceleration of the engine in any gear. But how? Well the atmospheric pressure sensor had to measure the pressure inside the airbox, because that is the air the engine is swallowing. The airbox is carefully designed by people like me to take full advantage of the forward velocity of the car to ram as much air in there as possible. This means we were increasing the air density. We weren’t allowed any sort of sensor that would tell the engine control unit (ECU) what gear the car was in. However, with some track testing, one could use the way pressure changed with speed in the airbox to determine that, if the pressure was ‘X’ above the ambient level seen at the start of the race, then the car was likely to be in a certain gear. To refine that process you just needed to know the RPM (another purely engine parameter). Hey presto traction control.

So it was kind of a trick. Use atmospheric pressure as a mean to adjust the acceleration rate of the engine to a given circuit. That way, to a certain degree, you can control traction.

As this work was done by the team it was achieved via spark cutting (and the engine supplier was not too happy about it from an engine reliability perspective). Input signals were engine RPM measured very frequently so that engine acceleration could be measured (hall effect sensors I believe) and atmospheric pressure (very accurate sensor) so that delta pressure could be assessed. Engine acceleration was limited in stages based on delta ("atmospheric") pressure. The driver would be sent out with the system "neutralized" to see what the track/tyres could handle. This would change if gear ratios changed (different gear ratio would require a different engine acceleration limit). The system would then be programmed with a number of stages of engine acceleration to suit the conditions. As conditions changed (track "rubbering in" etc.) the parameters would be tuned. 

During a race the conditions would change rendering the system more or less useful. If the tyres went off badly or it became wet the system would not control traction. If the track got better and better, the system would cut too much power – the grip available would allow more "engine" acceleration.

To be as precise as possible, what Benetton were doing allowed them, to a certain degree and under specific conditions, to emulate the effects of traction control. “Real” traction control is reactive, while the "trick" was more predictive and contingent on the conditions. It did not prevent wheel spin outright, but it made it less likely to occur.

You may find some of Schumacher's onboard footage from 1994. Watch them and see for yourself how effective the system was during acceleration and whether he experienced any wheel spins.

Launch Control

What LDRA Ltd. found in B194’s software was a hidden code for launch control, listed as Option 13. On July 29 at Hockenheim the FIA published a press release, stating that there was no evidence to suggest that Benetton had used launch control during the San Marino Grand Prix.

On May 1, the day of the race at Imola, the FIA requested that each team provide the source code for the car software they had used during the event. The Enstone team was reluctant to do it. They were dragging their feet. According to Ross Brawn, the Technical Director at Benetton, this hesitation was due to their engine supplier

We had no issues with the FIA in terms of them seeing what we’d created, but Ford did. They refused to give the FIA the source codes, as they considered them to be their intellectual property. We were stuck in the middle for a long time. Eventually we found a compromise with the FIA, and when they were studying the software they discovered a discarded portion of the infamous Option 13; it has been reported many times that it was a traction control, but it was a launch control.

We were then able to demonstrate there was a broken chain of software: it was impossible to use Option 13. But, of course, we got dragged through the courts, I think for other reasons. Eventually the FIA said there was no proof that we used Option 13.

Brawn is right about no proof, but not about the impossibility to use launch control. To be fair, the interview he gave to Adam Cooper for the linked article, took place ten years after the events.

Here is a quote from the aforementioned press release:

Benetton stated that this system is used only during testing. Benetton further stated that "it (the system) can only be switched on by recompilation of the code". This means recompilation of the source code. Detailed analysis by the LDRA experts of this complex code revealed that this statement was untrue. "Launch control" could in fact be switched on using a lap-top personal computer (PC) connected to the gearbox control unit (GCU).

When confronted with this information, the Benetton representatives conceded that it was possible to switch on the "launch control" using a lap-top PC but indicated that the availability of this feature of the software came as a surprise to them.

The recompilation of the code was one method to enable Option 13, but it was not the only one. Another method involved connecting the computer to the car, followed by the driver executing a precise sequence of gear paddle movements and positioning the gear, throttle, and clutch pedals in specific positions.

Benetton had launch control, but there was no evidence they used it, according to the company that uncovered the hidden code.

Of course, the press release issued by the FIA specifically addressed the San Marino Grand Prix. One can reasonably suspect that Benetton may have used Option 13 in other races before it was discovered and made public.

Below are all of Schumacher's starts in 1994. Did he use launch control? Did his starts drastically change after Hockenheim? Make your own mind.

The Two Suspicious Starts

The most suspicious of Schumacher’s starts occurred at the French Grand Prix, which is often cited by those who believe that Benetton were using launch control. The German had the start of his life, effortlessly overtaking Mansell and Hill as if he were a gazelle racing past two armadillos.

This is what Schumacher had to say about the start:

I catched the right moment to go, just when the red disappeared I was going. I couldn’t have done any better.

We have done a lot of development to our clutch which hasn’t been very good in the beginning of the season. Since we raced this new clutch it’s giving us a lot better performance in the start and that’s what you see since then, we’re doing always good starts.

There is also a start at Aida, which is sometimes mentioned in discussions about the alleged use of launch control. Senna got poorly off the line and lost the lead to Schumacher before reaching the first corner, where his race ended after being punted by Mika Hakkinen and subsequently collected by Nicola Larini.

In the Pacific Grand Prix Schumacher probably started from the better side of the grid. According to Eurosport commentators Allard Kalff and John Watson, a dragster had been practicing on the section of the track where cars starting from the even-numbered grid slots were positioned, resulting in more rubber being laid down. As a result, Senna attempted to switch his pole position to the inside, but to no avail.

That’s all on the topic. You have Benetton’s version of the driving aids controversy. Whether you’re willing to believe it or not, it’s up to you.