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Formula One Racing Technology (today)
For a time, the argument could be made that the Can-Am series of the late 1960s and early 1970s was the innovation powerhouse of the world, bringing us high wings, automatic transmissions, and fan-driven ground effects cars, largely thanks to the ingenuity of Chaparral Cars. In the more recent past, F1’s star had been eclipsed by the levels and variety of innovation seen in the hybrid prototypes of the World Endurance Championship (WEC), the cars that race the 24 Hours of Le Mans. Formula One has responded in a most dramatic way, sacking the previous formula of tightly regulated 2.4 liter V-8’s with a KERS (kinetic energy recovery system) that used regenerative braking to recharge the lithium battery pack. This new formula allows the return of turbocharged engines.
In the 1980s, F1 had largely unrestricted 1.5 liter 4-, 6-, and 8-cylinder variants which were said to generate between 1,200-1,300 hp. For 2014, it was a heavily regulated 1.6 liter V-6 configuration with two hybrid power units, including one (MGU-H) that converts heat from the exhaust into electric energy, which is stored in the Energy Storage battery pack, located just below and behind the driver.
Paddy Lowe, technical director of Mercedes AMG, explains. “When KERS power packs first came in back in 2009, it was left to the teams to set their own safety standards. Now, you have to put the battery within the confines of the safety cell, where it is well protected in a shunt. In a current Formula One car, there is nothing that’s that easy to change on any of it, but when you drop the floor, the battery is accessible and you can probably change it in a half an hour.”
The hybrid power available has been doubled, from 80 to 160 horsepower, but it comes at a cost, with a requirement for far higher efficiency on the engine side. Fuel supply has been limited to 100 liters for a Grand Prix distance. There is also a restriction not allowing a fuel flow/usage of greater than 100 liters/hour. This has been achieved with varying success by the engine suppliers. Most successful has been Mercedes, with their cars finishing 1-2 at the United States Grand Prix and in the top five spots in a race in Russia on cars of three different constructors.
Obviously, there are many well designed assemblies that, when combined, resulted in dominance. One of the more innovative was separating the turbocharger turbine (at the rear of the engine) from the compressor on the intake side, which runs off a shaft which runs the length of the engine. Placing the compressor close to the cool air intake has advantages in both density and velocity of the intake tract. It also moves a bit more weight closer to the center of gravity (CG) of the car. With the engine specification being frozen for the year, Mercedes locked in this design advantage for 2014 and exploited it to great effect.
Drivers have a role to play in this equation. In past years, the driver would push the “KERS button” to kick in that extra 80 hp for approximately seven seconds per lap. For 2014, that actuation occurred automatically. Adrian Sutil drives the Sauber and explains, “On a hot lap in qualifying, when everything is perfect, you shouldn’t run out of energy anywhere, the power is consistent. In the race, we have different mappings for the engine to sometimes save fuel and you feel a dip in the acceleration at the higher speeds.”
One might assume the circuits with the greatest issues for fuel mileage might be the mighty high speed circuits, but that is not the case. Nico Hulkenberg of Force India said, “The race in Sochi was the most critical race for fuel savings. It is full throttle time and that is what uses the most fuel. You can coast and drive as efficiently as possible.”
This is confirmed by Pat Fry, Director of Engineering at Ferrari, who added, “Tracks where there is lots of acceleration, long straight, stop, long straight, stop… Melbourne, for instance, is quite a severe track for fuel consumption as is Canada, or Sochi.” The engines have a massive increase in torque, so with reduced downforce, the cars twitch and wiggle around at times.
There has been a lot of criticism about the sound of the cars. The 1.5 liter F1 cars of the 1980s were sonically far removed from the screaming normally aspirated V-12s that followed in 1989. For the first time in a generation, hearing protection could be described as optional.
Suspension is typically actuated by pushrods connecting the hubs to the shock/spring units inside the carbon chassis. In 2009, Adrian Newey of Red Bull shifted over to pullrod rear suspension to get those bits out of the airflow, allowing a tidy package at the all-important underside of the car. For the past three seasons, Ferrari has integrated a pullrod front suspension as well, which looks nearly horizontal, seemingly giving up the mechanical advantage needed when the wheel moves vertically. You would think they would need tremendous spring rates to achieve a conventional wheel rate with such minimal ‘pull’ on the pullrod. “When you have a high chassis with the wishbones angled down,” said Fry, “in bump, the track of the car increases. When you actually do the kinematics, it’s not as bad as it looks. The vortices coming off the front wing, we don’t want those hitting anything. It’s just a small aero benefit, really.”
With the increased effect by the regenerative braking, seamless integration when combined with the hydraulic brake system became a priority. “When we had KERS with the 60kw recovery, that was just about manageable with conventional brakes and brake balance,” said Lowe. “With 120kw recovery, there was no way to not allow brake-by-wire and it has made the brakes a lot more controllable and stiffer.”
These new “brake-by-wire” systems use an electronic actuator at the rear wheels to provide a more seamless interface between the formerly hydraulic brake system (pad to disc) and the regenerative braking which in F1 speak is the MGU-K. Apparently, this results in a firmer pedal than conventional hydraulic braking systems, which can have a slight amount of expansion in the flexible brake lines. Although it seemed unlikely as there is still a hydraulic conventional brake system at the fronts as well as a hydraulic backup at the rear, Pat Symonds, technical director of the Williams F1 team also confirms that their system also has a much firmer brake pedal than before.
All-important in F1 is the packaging and resultant aerodynamics. Gone are the “blown diffusers” of past years, where engines also served as air pumps, or giant leaf blowers, which then could be directed into the underbody of the car to provide the greatest effect. It had been tried many times before, but was abandoned when the differences between on- and off-throttle aerodynamics became too much to resolve. The solution was the development of off-throttle blowing, which kept the engine pumping air even in off-throttle applications. Coanda effect exhaust routing (where exhaust gases are attracted to nearby surfaces, such as the diffuser) was similarly banned.
Another issue has been the high noses of the cars launching skyward off the rear wheels. Since John Barnard’s Benetton of 1991 featured the high nose with underslung wing, this has been a problem. In recent years, the maximum nose tip height had been reduced from 650mm to 550mm, but now reduced to 185mm. The appearance is unfortunate at best, and an artistic disaster at worst. Referred to as “Aardvark” or “Anteater” noses, some resemble a proboscis, or in the case of the Ferrari, a Platypus. Lotus has adopted a twin “tusk” nose, and after trying the Platypus, reverted back to the tusk version.
Of course, since Formula One is an entertainment business, they have come up with performance enhancements which help overtaking cars pass. Drag Reduction Zones allow the overtaking car to drastically reduce the drag from the rear wing and shoot past the car in front. This can often be repeated as now this advantage transfers to the previously overtaken car.
with pix
HERE