© Getty ImagesBulls' Guide To: Racing At AltitudeMexico City is the highest track F1 visits. That brings with it a few challenges…
Themapmightshowthatwe’reheadingdowntoMexicofromTexasthisweekendbut,inreality,we’reheadingup.EveryF1circuithasitsowndistinctivecharacteristics,andtheonethatstandsoutabouttheAutódromoHermanosRodríguezisthealtitude.At2,285mit’sthehighestplacewerace–andthatreallymakesahugedifferencetothechallengeofgoingracing.
Racing nearly one-and-a-half miles above sea level isn’t just a bit higher than other circuits, it’s a lot higher: our next destination, the Autódromo José Carlos Pace (aka Interlagos) is down at 800m, with the other 20 circuits strung out in reasonably even order below that, all the way down to the Baku City Circuit, 14m below sea-level. Mexico City towers above everything else. It’s a giant.
Racing In Mexico Comes With Some Unique Challenges© Getty Images
The reason this matters is that the air gets thinner with altitude – and lots of things in a Formula 1 car depend on air pressure to work. Lower air pressure, less air, reduced performance from the car. And every generation of cars have their own issues.
When F1 visited the Autódromo Hermanos Rodríguez in the 1990s and, indeed, in the 1960s, the primary impact of the altitude was measured in engine output. The combustion process burns oxygen, and there’s simply less oxygen available at altitude. The rule of thumb is that, for every 100m gained in altitude, engine output drops by one per cent. Back in 1992, the last time F1 ran in Mexico with normally-aspirated engines, the mighty, 3.5l V12 Hondas would have produced around 22% less power in Mexico than they did in Japan, when racing close to sea-level at Suzuka.
That isn’t an issue in the modern era because these cars are turbo-charged. Unlike their normally-aspirated predecessors, air is compressed by the turbo (which is powered electrically, from the Energy Recovery System) and forced into the cylinders under pressure. The engine can burn as much oxygen as it does at sea-level – but at the cost of the turbo having to work much harder than it does elsewhere. Increasing the rpm of the compressor obviously places more strain on the unit and leads to more failures – but it also makes it run hotter and require more cooling, which is another challenge at altitude.
Last Time On Track In Mexico© Getty Images
F1 cars are air-cooled, and lower air density means, in basic terms, less air is available for cooling. “In terms of running the car, we’re got to work with less air,” says Paul Monaghan, chief engineer – car engineering. “All the air-dependent systems, whether it’s brake cooling, engine cooling, gearbox, are going to struggle.”
The work-around is a car that’s more ‘opened up’, running the sort of cooling packages usually reserved for very hot races. This manifests itself in bigger brake duct and air intakes and looser bodywork around the rear of the car. Naturally this creates more drag – but altitude isn’t all bad news: the thinner air means there’s less overall drag to contend with in the first place, so the lap-time hit the car takes is correspondingly smaller.
In The Pits In Mexico© Getty Images
The flip-side of lower drag is that the car also has less downforce. “Performance-wise, the amount of downforce you generate is going to be substantially less,” says Monaghan. This leads to some unusual package choices at Autódromo Hermanos Rodríguez. At 4.304km, this is one of the shortest circuits on the calendar, but it has a disproportionately long main straight. Under normal circumstances, that would induce teams to take downforce off the car to maximise top speeds.
At Autódromo Hermanos Rodríguez, however, because the air is so thin, teams are always searching for as much downforce as they can find, usually running maximum downforce packages, of the type usually seen on low-speed tracks like Singapore, but still getting the sort of extreme high speeds usually seen at places like Monza, where they run the low-drag packages to maximise speed on the straights. Mexico sees similar speeds to Monza, albeit with huge wings on the car, rather than the skinny ones used at the Italian circuit. This is why Autódromo Hermanos Rodríguez holds the speed trap record in F1. Valtteri Bottas, driving for Williams in 2016 was clocked at 372.5km/h on the main straight. The highest speed ever recorded in an F1 race.
Running The Cars At This Altitude Is An Impressive Feat© Getty Images
Finally, the car isn’t the only thing that can struggle at altitude. You’ll see a lot of mechanics and other team personnel breathing heavily this weekend, particularly when lifting and carrying, and there might be fewer heading out in the evening to run the track than usual, simply because breathing – for those not accustomed to Mexico City – is quite difficult. That obviously manifests itself in the drivers also. In other sports, the approach might be to arrive three or four weeks early and acclimate, naturally allowing the blood vessels to adapt, changing the amount of haemoglobin in the system, increasing the production of Erythropoietin (better known as EPO, famed for its role in various cycling doping scandals) to allow the athlete to take in more oxygen and distribute it to the muscles more efficiently. Obviously, the frantic F1 schedule doesn’t allow for those sorts of luxuries, and the drivers have to get by as best they can.
“The biggest thing we’re trying to avoid is altitude sickness,” says Brad Scanes, Max’s physio. “The body uses oxygen as an energy system and, above 1500m, your work capacity is reduced by about three per cent. Too much exertion makes the body try to use oxygen it just doesn’t have available, you can’t handle it, and get sick. The way to avoid that is getting out to the event earlier. Of course, we’d like to have two or three weeks, but it’s never going to happen. Much like the case with heat training leading into the Singapore Grand Prix, we do what we can in the time available – and even two or three days is enough time to get that adaption process started.”
The standard method of preparing the drivers for the demands of the Mexican Grand Prix is to do some low-level cardio work in the city. Nothing that pushes the limits but just enough to encourage the body to adapt. There’s also tweaks to the diet that can help – and unusually they’re ones that the drivers enjoy.
“Increasing your iron-intake is useful as the extra iron in the blood helps. You can either start taking iron supplements three or four days before the start of the event, or adjust nutrition to eat food with a higher iron content,” says Brad.
And that’s the Mexican Grand Prix. A high altitude blast that often leaves us breathless with more than just excitement.
One Of Our Favourite Parts Of Autódromo Hermanos Rodríguez© Getty Images
