Preview: United States GP
Following a successful and intense first race at the brand new Circuit of the Americas, Formula One heads back to America for the US Grand Prix, the penultimate race of the season.
The circuit was praised last year for its unique features and challenging nature for the drivers. The first turn is well known for its steep upward slope and blind entry, following a drop into a sequence of medium to high speed corners inspired by Silverstone's Becketts complex. The paddock is quite unanimous that this is one of the best circuits on the calendar that were designed by Hermann Tilke.
Just like Abu Dhabi, Austin is one of the few circuits on the calendar to run in an anti-clockwise direction. Other anti-clockwise circuits are Korea, Singapore and Brazil.
There will be two DRS zones at COTA. The detection point of the first will be 150 metres after Turn 10, with the activation point 320m after Turn 11. The second zone’s detection point will be 65m after Turn 18, with the activation point 80m after Turn 20, just before the start/finish line.
Circuit highlights
Turn 1 Turn one in Austin is one of the greatest first corners of the season. The run from pole is 500m but the track goes steeply uphill, with the turn-in point for the corner at the crest. Gear ratios will be spaced out here to give the driver strong acceleration up the hill without losing any speed at maximum velocity. At the top of the hill, just when the driver brakes for the hairpin, the load running through the car is suddenly released, which can cause massive instability if the engine is not completely in phase with the mechanical set-up of the car.
Turns 2 to 4 After the first corner the driver goes back up through the gears to reach seventh for turns 2, 3 and 4, which are taken flat out with an average speed of 280kph. Similar to Maggots and Becketts at Silverstone and the Esses at Suzuka, the driver needs to be precise on the throttle and carry the speed all the way through rather than brake and accelerate. The engine needs to be correspondingly smooth throughout the turns, delivering constant levels of torque. If the engine is too aggressive the car will be unstable and ‘bitey’ on turn in, which will only lose time and wear the tyres quicker.
Turns 5 – 6 Turns 5 & 6 are not quite as quick as the previous trio, but nonetheless fast; around 220kph in fifth gear.
Turn 11 to 12 Turn 11 provides a good potential overtaking opportunity, as drivers exit the third gear Turn 9 into the flat-out Turn 10 before braking heavily for this hairpin.
Similar to Abu Dhabi and Korea, the longest straight is not the pit straight. In Austin it is 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 with a top speed of around 315kph, which will be held for 2.5secs. Since this straight runs in a different direction to the pit straight, 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.
Car setup
Rear Wing This will be set at a similar level to that used in Abu Dhabi. Maximum speed reached on the straight is around 315kph so it has a long straight, but this is intermingled with a diverse mix of corners; both high speed and low speed.
Front Wing Relatively more front wing is required here to counter understeer through Turns 16 – 18 where the car would otherwise push through the turn; killing speed and wearing the front tyres.
Suspension This is a balance between high speed stability for the flat out Turns 2 – 4 and the change of direction requirements later in the lap.
Brakes Brake cooling levels must be set to maintain sufficient heat at the end of the long straight, while avoiding potential overheating in the technical section. Balancing temperatures will be the name of the game, with no issues expected in terms of wear.
Engine Average engine revs sit at around 15,500rpm here [mid to high range vs. other tracks] with 60% of the lap spent with the throttle wide open. There are some great corners, such as turn 1 and the final section, were the engine needs to deliver the right balance between response and smoothness. This is one of the tracks where we work especially closely with the chassis guys as there are a couple of blind turns where the driver will need to ‘feel’ the corner and have the confidence that the car will behave as he wants.
Equally the situation of the track, in the middle of the vast Texan grasslands, is a challenge. The lack of ambient humidity, on a par with Abu Dhabi and Bahrain, has two specific effects on the engine, one positive and one negative. The positive is that the air contains more pure oxygen so the engine is more powerful, however the very negative side is that the aridity stresses the engine. In fact, you can get an engine to ‘detonate’ if it is not managed correctly. This is a very destructive phenomenon basically consisting of an abnormal combustion of the air and the fuel in the engine, with subsequently massive stresses on the piston. To prevent this, ignition timing is tuned very carefully.
Tyres The most conservative allocation of hard and medium compounds will be in use here. The layout and track surface will make unlocking maximum tyre performance quite challenging, whilst the allocation of the two hardest compounds means degradation is unlikely to be too much of a factor in the race.
The track surface at Austin, which was new last year, is generally quite smooth. However, with the passage of time, surfaces generally tend to become a bit more abrasive year by year. This happens as the bitumen at the very top is swept away, exposing the small stones out of which the asphalt is made.
Quick facts
Number of corners: 20 (11 left, 9 right)
Maximum speed (no DRS): 320 km/h
Minimum speed: 80 km/h
FIA corners below 100 km/h: 5
FIA corners above 250 km/h: 4
Average lap speed (qualifying): 200 km/h
Distance from pole to apex of T1: 280m
Braking events: 10 (4 hard)
Pit-lane length under speed-limit control: 395m
Pit-lane time at 80 km/h: 17.8s
Full throttle per lap (% lap distance): 68%
Full throttle per lap (% lap time): 56%
Longest period at full throttle: 13s
Average gear changes per race lap: 54 (3024/race)
Braking energy: average
