New tech on the cars in Melbourne
It may be the early part of the season, when the long distance flyway races make logistics difficult, but many teams are pushing really hard on development. There are quite a few updates on show this weekend in Melbourne. Several teams have new aerodynamic parts including new front wings for Red Bull, Renault and Ferrari.
The Ferrari wing has a new endplate with a smaller vertical fin, outside the end plates, featuring an S shaped vertical profile, instead of a straight one. It is about 5cm lower than the previous version. It’s main function is to give less pitch sensitivity. Although this wing gives slightly less downforce than the previous version, it causes less turbulence in airflow around and under the car and works better with the new wheel fairings.
On Friday in Melbourne only Alonso used it, but both drivers will use it for the rest of the weekend.
Melbourne is a circuit where the tyres often “grain”, which causes them to lose performance and it is something all the teams will be guarding against in the race if they want to be competitive.
Last year the graining on the softer of the two compounds was very bad and proved a decisive factor in the race. Many teams found that after just six laps the rear tyres had grained badly and were losing two to three seconds per lap. This year Bridgestone has brought tyres, which are a step harder. So instead of super soft and medium, they have brought soft and hard.
Graining is where the rubber shears away from the top surface, caused by a high level of sliding at high loads, both lateral and longitudinal. Lateral comes from sliding in corners, longitudinal comes from acceleration and braking.
Temperature has a lot to do with it, probably more than any other factor. Imagine a plastic ruler left in the fridge – when you take it out and bend it, it will snap. But if you bend a warm ruler it will flex easily.
It’s the same with F1 tyres – if they are being used below their operating range the rubber will be less compliant and will shear off more easily. The hard tyre grains less because the compound shear strength is higher.
Another major factor is the track surface at Albert Park. It is quite old and has low micro and macro roughness, which basically means that the stones in it are small. The result of its age and smoothness is that the surface is very low grip and this means that the tyres grain laterally here because the car slides in the corners.
Watch out for the rear tyres graining from the inside shoulder towards the outside.
Ride height adjusters
A lot of talk in the paddocks of both Bahrain and Melbourne has centred on ride height adjusters on the Red Bull and Ferrari cars in particular, which means that they can optimise the aerodynamics in qualifying and for most of the race.
Up to a point, the lower you can run your car the more downforce it will have. But this year with refuelling banned, teams need to set the ride height so it works for a low fuel qualifying lap and then without changing it in parc ferme before the race, also works when the car has 160 kilos of fuel in it. Inevitably the extra weight will lower the car on its suspension and mean you will be running 3mm lower in the first stint of the race than in qualifying. As the fuel burns off the car rises. If you can lower the car a few millimetres at your first pit stop, you will have more downforce for the rest of the race.
It is perfectly legal as long as the car is stationary when the change is made and the gain is worth a few seconds over a race distance. Here’s how it’s calculated; every 1 mm of ride height you move is worth 5 kilos of downforce, which in turn is worth 0.05 seconds per lap. So if you pit on lap 18 in Melbourne, you can lower the car will have 40 laps of benefit, which is worth two seconds. If you lower the car by 4mm, which is realistic, you will gain 8 seconds. It is only worth it if you can make the change easily in the pit stop without losing that time.
Ferrari’s system is manual and very obvious. There have been suggestions that Red Bull has a more sophisticated system, which allows the car to run low in qualifying trim but then raises itself up when the 160 kilos of fuel are loaded in and lowers itself again as the fuel burns off. The key to that is making it legal.
Other teams are scratching their heads about how Red Bull might have achieved that, but one suggestion is that they may be exploiting the regulation that allows teams to re-gas pressurize the dampers between qualifying and the race. If this is the case then they would get the benefit of running the car low in qualifying and then raise it up when the fuel is added. Hence their stunning qualifying form.
More on the McLaren rear wing
The McLaren rear wing with its novel airflow arrangement via the sharkfin engine cover, gave the team around 4/10ths of a second per lap in Bahrain, because it meant that the car could travel down the straights 5km/h faster thanks to the rear wing “stalling” and thus shedding drag. There has been a lot of speculation about how this is achieved.
It is known that the air enters the cockpit via a duct on the top of the monocoque and passes down a channel. The driver raises his left knee to close off a gap in the channel which sends high pressure air through the sharkfin and out of the back of the rear wing, breaking away the airflow which passes underneath. But the clever part of the system is how the air switches direction in the engine cover. This is done using a Y shaped junction and a science called fluidics, which is where air can be made to have digital properties.
Sauber has become the first team to attempt to copy the idea, with a duct on the left sidepod of their car. But it is hard to see how it will be optimised to the degree that the McLaren is.
Ever wondered how they test whether the cars are legal? After every race the F1 cars have to be checked over to make sure that they comply with the regulations. But the pre-race legality checks are not carried out by the FIA, they are carried out by the teams themselves. It is up to them to make sure that their car is legal before the action starts.
All the FIA do pre-event is to check that the safety features are in working order, things like the monocoque, the electricity kill switch, the rear light and the fire extinguisher.