Technical challenges for the US GP
The Circuit of the Americas is to host this weekend's USA GP, marking the return of F1 to the country since the event at Indianapolis in 2007. The new venue promises to be a severe challenge for car and driver, so we have a look at the technical characteristics of the track.
Chief among the challenges is, of course, the fact that no team has yet turned a wheel in anger here. Former F1 driver David Coulthard drove a Red Bull Racing showcar here when circuit construction had just begun and more recently Lotus test driver Jérôme D’Ambrosio piloted a 2010 Renault R30 on opening day at the track, but beyond those very different laps teams will only have simulator data upon which to base their weekend preparations.
That should make Friday’s free practice sessions labourintensive workouts for the teams, though again it will present a challenge as the new track will undoubtedly be largely free of grip in the early stages of the weekend.
Simulations predict an average speed over one lap of 196kph during the race and just over 205kph during qualifying. There are two long straights but the average speed is lowered by the high volume of low gear corners; eight of the 20 turns are taken in third gear or lower. This puts the Circuit of the Americas in a similar bracket to Valencia.
Similar to Abu Dhabi, the longest straight is not the pit straight, but rather the burst between turns 11 and 12. The straight here is 1,016m, meaning the engines will spend a touch over 13secs at wide open throttle. Top speed is predicted to be 314kph at the end of this straight and the engine will spend 2.5secs at max revs before braking for the hairpin of turn 12.
The second long straight is the pit straight. Both straights run in different directions so correctly selecting seventh gear will depend on wind direction on the day. Selection for the one may compromise end of straight speed for the other, so ambient conditions will be carefully monitored throughout Friday practice to find the optimum ratio.
The track is similar in power sensitivity to Malaysia, with 57% of the lap taken at full throttle during the race, and just under 60% during qualifying. The predicted lap time is around 1min 39secs.
Three hairpins triangulate the track; turns 1, 11 and 12. Revs will drop to 9,500rpm and the car speed to just 80kph. All three come after a long period of open throttle, meaning engine braking and rear stability on the apex are crucial. The exits and correct engine response from the hairpins are however equally important since they each lead back onto another straight.
Fuel consumption is one of the highest of a season over one lap, similar to Abu Dhabi. The lower temperatures of Austin offset its relatively high altitude and change of gradient, but low ambient humidity and the twisty first and last sectors where the driver is constantly on and off the throttle increase consumption. The starting fuel load will be one of the heaviest of the year, on a par with Abu Dhabi and Melbourne.
The Circuit of the Americas will feature a single DRS Zone, on the back straight, between Turns 11 and 12. The activation zone is likely to be approximately 650m before Turn 12.
Facts and numbers
3.7: Highest g-force experienced for 4 seconds at T10 and T11
14: % of the lap spent braking
45: Total straight per lap (%)
59: Gear changes per lap
63: % of the lap at full throttle
75: Lowest apex speed (kmh) at T11
200: Distance in metres from start line to first corner
280: Highest apex speed (kmh) at T3
315: Top speed (kmh)
1000: Longest full throttle burst (m) between T11 and T12