Race-starts have been quite fragile this season with much more manual input from the driver. F1 tech specialist Craig Scarborough explains to Mobil 1 what an F1 driver needs to do to get away smoothly when the lights go out.
Lewis Hamilton has encountered a rare weakness this season with his struggles at the race start. There have been too many occasions in which he’s bogged down, had excessive wheel spin and lost crucial places at the start of the race. His teammate Nico Rosberg has definitely been on top in this department, the German proving much more consistent in the opening seconds of most Grand Prix.
The mixed results in race-starts shows which driver’s have done their homework and managed to eke out an advantage as Scarborough explains:
“At a basic level, making a launch in an F1 car is much like that in a road car which uses a manual gearbox. The driver needs to balance the revs and the clutch, phasing the pedals to get just the right engine torque at the point when the clutch is released, before progressing the two as the car starts to accelerate.
Of course, we know from our driving lessons that too little throttle pedal will stall the car, and too much will send the tyres spinning. Getting the balance right sees the car fire off the line, with just a tiny fraction of tyre slip providing the quickest getaway. In a heavy and underpowered road car, this balance can be found quite easily, even when trying to beat another car off the lights. However, when it comes to powerful and erratic race cars, the process needs to be far better controlled for the optimum start.
If we look back to before the ‘90s, starts were fully manual, with the driver getting a feel for a heavy clutch and throttle pedal. As such, fraught nerves were the major variable. As we moved into the 1990s active era, the launch became automated, with drivers simply needing to release a paddle or button to set the car off for a fully-managed active launch process. The only variable here was the actual difference between the car’s engine power and traction, as the start itself was optimal for that car. Thus, we had a lot of very equal starts up and down the grid.”
– Craig Scarborough
The turn of the 21st Century saw a controlled start continue, if not evolve slightly. Again, driver’s weren’t really rewarded or punished in the start phase.
“At the moment of lights out, the first clutch paddle would be released, leaving the driver to then control the car on the throttle for any wheel spin. At this point, the clutch would be only half engaged, to prevent too much power getting to the road. Then, once the tyres are gripping and the revs are rising, the second paddle would be fully released to pass full engine power to the wheels.
With this process, starts were once again largely consistent and any potential win or loss at the start was negated.”
– Craig Scarborough
This season has seen a massive change with much of the autonomous start-procedure gone. These race-starts don’t just make the opening run down to turn-one more exciting, but also provides another way in which the drivers can gain or lose an advantage.
“Nowadays, both the ‘Bite Point Find’ and the double clutch paddle start process are banned. Drivers have to get a feel for the clutch bite point and react to it accordingly, rather than just adjust the paddle settings. Equally, the two stage start with the clutch paddles has to be done with one clutch paddle being released part way, then fully released through the start process.
Clearly, this reintroduced jeopardy into a race start and, as demonstrated many times this year, has led to cars jumping up the order, as well as dropping down, at the start.
Complicating this current, far more manual, process is the engine reacting to a fixed throttle position for a long period. F1 engines are designed to be run under load, not revving in neutral for long periods. In such conditions, the multitude of engine parameters change – things get hot, pressures rise or fall and the sensors tell the ECU what’s going on.
It can be the case that the ECU gets confused and the RPM resulting from the fixed throttle position starts to vary. Of course, with varying RPM the driver gets different torque available. So, should the engine speed rise or dip as the start happens, variability will occur, generally either in the form of bogging down or spinning the wheels.”
– Craig Scarborough
So what about 2017? Well, the starts will potentially be less randomized as team’s get to grips with a sensor that could provide some consistency as an ECU input.
“For a few years, F1 cars have had a torque sensor fitted to the shaft between engine and gearbox. Up until now, this sensor was used for FIA monitoring purposes but, for 2017, teams will be able to use this sensor as an input to the ECU. Therefore, the driver will be able to request a set throttle pedal position and, rather than the engine’s response being a prediction of the torque delivered, it can actually adjust itself and deliver the demanded torque. This takes the torque variable out of the start, which should make for far more consistent starts.
So, from a year of quite influential start performances, 2017 – with its very different cars – should again return to the racing after Lap 1 to decide a race. Yet, with clutch and grip levels still variable, drivers cannot become complacent, as the race will still have the potential to be won or lost at the start.”
– Craig Scarborough
So 2017 will theoretically provide a more manageable platform for drivers when propelling from the grid-slot. Some drivers will see leveling the field as a positive but those who are making up places regularly this season will surely be cheesed off that their edge won’t be as relevant.