American Formula One viewers squinting through bleary eyes at the live early-morning broadcasts from Europe have noticed changes to the sophisticated race cars for the 2017: they are visibly lower, wider and squatter-looking than last year’s cars.
What hasn’t changed is the continuing use of the hybrid-electric systems with electric motors to augment the combustion power of turbocharged 1.6-L 90-degree V6s. Teams admit that the internal-combustion engines produce more than 600 horsepower, while the electric motors add another 160 horsepower for about 33 seconds during each lap—though it is suspected that the front-running Mercedes and Ferrari teams are well ahead of the official ratings.
Engines are restricted to 15,000 rpm by the regulations, but a mandatory instantaneous fuel-flow limit has the practical effect of keeping them from ever reaching that peak.
The 2016 system of limited "tokens" that permitted in-season updates to powertrain technology has been eliminated, permitting unlimited ongoing development, which is anticipated to help power output laggards Honda and Renault catch up with front-runners Mercedes-Benz and Ferrari as the season progresses, rather than locking them into their inferior places, as was the case in past seasons.
Lap times have tumbled this season as a consequence of fatter Pirelli racing tires and wider wings that stick them to the pavement with enough grip that the cars now corner with an even more neck-straining 6.5gs of force.
“Practically just by looking at it, one can tell the speed the new car has increased as a result of more downforce and shorter braking distances – measured against lap time, not top speed – it is written all over its face,” enthused Sauber technical director Jörg Zander about his team’s 2017 challenger.
Most of the changes for this year, as Zander suggests, are visibly obvious. Front wing span is increased from 1650 mm (65 in) to 1800 mm (70.9 in) and the car’s maximum width is up from 1800 mm to 2000 mm (78.7 in).
At 950 mm (37.4 in), the rear wing is 200 mm (7.9 in) wider than before, but at 800 mm (31.5 in) tall, it sits 150 mm (5.9 in) lower than in 2016. Rear downforce is further bolstered by an enlarged diffuser, which is now 175 mm (6.9 in) deep rather than the previous 125 mm (4.9 in) depth. Finally, the maximum width of the car’s fuselage is increased to 1600 mm (63 in) from 1400 mm (55.1 in).
“It is a sea change for Formula One,” noted Bob Bell, technical director for RenaultSport.
The sport needed one after several seasons of predictable Mercedes-Benz dominance. “When you get a reset, that [performance] gap closes down,” he said. “The regulation changes help level the playing field a little bit.”
The deregulation of some aerodynamic restrictions also permits some creativity, Bell pointed out. “We are freer on aero than before.”
RenaultSport explored some of those options using Europe’s largest 3D printer for sintered metal parts to produce components for the team’s 60%-size wind tunnel model. The 20,000 printed metal parts each year are supplemented by the team’s 3D Systems plastic printer.
Today, teams use 3D printing for models, but McLaren revealed that it is using a Stratasys 3D printer at the track to produce some replacement parts on-site. RenaultSport predicts that within a decade teams will be able to replace complex castings such as the gearbox housing with printed parts.
An invisible change to the 2017 cars that is related to the wider wheels and tires is the use of “blown hubs.” The cars’ wheel hubs have been designed to flow air to cool their bearings and the cars’ brakes, but with the wider tires creating more aerodynamic drag, teams were motivated to reduce front-tire drag by increasing the airflow from the brake cooling-duct by filling the low-pressure wake alongside the wheel face with higher-pressure air from the hub.
Pirelli says it has rethought the entire concept of the F1 tire in response to changes in technical regulations that make the tires wider than before. New construction techniques have improved the distribution of forces in the bead area and footprint, providing greater consistency and driveability through corners, according to the company.
The object, in response to criticism in recent seasons that drivers were forever taking it easy on their tires when fans wanted to see them race, was to provide more durable tires as well as to raise the level of grip.
“Sometimes a problem in the past was that the drivers could not be aggressive and attack on the tires,” noted 1997 F1 world champion driver Jacques Villeneuve. “Right now it is a tire where the drivers can actually be aggressive.”
“Drivers can now enter a corner a little bit sideways and not destroy the tire and still be aggressive,” he explained. Last year, such behavior would quickly disarm an attacking driver, as the ruined tires would slow his car.
Tires for 2017 are about 25% wider than before, with the fronts growing from 245 mm (9.6 in) to 305 mm (12 in) wide and the rears expanding from 325 mm (12.8 in) in 2016 to 405 mm (15.9 in) this season. These wider tires are also 10 mm (0.4 in) larger in outer diameter, though the wheel diameter remains unchanged at the sport’s historic 330 mm (13 in).
With the battery-electric Formula E cars running a much-larger 457-mm (18-in) wheel diameter, the traditional F1 wheel diameter seems ripe for updating the next time the tire rules are revisited—but for now that one measurement remains sacrosanct.
Pirelli distinguishes its tire compounds using different-colored sidewall lettering so that fans can tell which tires that drivers are using, providing an immediate visual cue regarding how much grip the driver might have or how long the tires might last before the need to pit for fresh rubber.
This season sees the arrival of a new, purple-lettered “ultrasoft” compound that is grippier still than the existing red “supersoft.” Yellow indicates “soft” and white is for medium tires. Orange sidewall lettering indicates “hard” compound. For the rain tires, intermediate rain tires are green and the full rain tires are blue.
“For the 2017 season, the sport asked us to develop tires with less degradation, which allow drivers to push to the maximum,” said . “The target was for lap times that were five seconds faster compared to Barcelona (race course) in 2015. Yesterday, Valtteri Bottas set a best time of 1:19.705 on ultrasoft tires. Considering that the pole time in 2015 at Barcelona was 1:24.681, I would say that this objective has been met.”
Even the regular, yellow-lettered medium-compound Pirelli tire is hugely improved from last year. “At the test in Spain, it appears to be a very fast, very strong and extremely consistent tire, enabling drivers to be extremely fast. Already it is more than three seconds faster than the same situation last year.”
Indeed, this seems to be a summation of the overall results of the 2017 Formula One changes, which have seen drivers racing harder than in recent years, to the satisfaction of the fans. While many enthusiasts still long for the sound of the late V10 engines, 2017’s changes are indicative of a new responsiveness to fans’ interest in more compelling racing and more exciting cars, which bodes well for upcoming seasons.