Why F1 cars find it hard to follow each other for an overtake in 2015
We heard this week that McLaren has had some challenges getting its new short nose configuration through crash testing, but what is behind this fas...
We heard this week that McLaren has had some challenges getting its new short nose configuration through crash testing, but what is behind this fashion for the short nose on F1 cars this season? And is there any connection with the mandatory low noses now in F1 with cars struggling to follow each other this season in preparation for an overtake?
Here, with the help of our F1 technical adviser Dominic Harlow, former chief race engineer for Force India and visual renderings from Giorgio Piola, we can try to explain.
Low noses became mandatory because of safety concerns; cars T-boning other cars could be very dangerous for the driver if the nose of another car hits his cockpit area.
But the noses we saw in 2014 were not only ugly, they also hurt the aerodynamics. This year they've made some regulation changes to improve the look, but the teams have also pushed hard to improve the aero, Mercedes are there, Red Bull got there too recently. So far there is no sign from Ferrari, but it's probably just a matter of time.
What's the issue here with the low noses?
The biggest effect of the low noses (above) is that on the neutral area in the middle of the front wing. F1 aerodynamics is all about generating a vortex in key areas. This one is crucial because it conditions the way the air passes under the front of the monocoque, where the drivers legs are, and channels down to the key downforce generating areas of the floor, diffuser and underbody.
The low nose gets in the way of that work and has a negative and disruptive effect on the vortices going to the floor and diffuser.
So by shortening the nose section (above), while still maintaining the regulation dimensions of the front of the car, you can see that a lot more air passes over that key transition in the neutral area at the centre of the front wing, managing the airflow better to the sensitive areas, which generate so much of an F1 car's downforce.
Why are F1 cars finding it hard to follow each other closely to set up an overtake this year?
There have been many complaints from drivers about not being able to follow other cars this season, that have been broadcast on the TV world feed. This is not a new complaint, but the transmission of the messages makes it front of mind for fans.
The 2014 regulations moved the front wing endplates inwards (above) in comparison with the previous generation of cars (below), so they have a narrower front wing.
The idea of the wider front wings, brought in for 2009, was that by washing air outwards around the front wheels the front wing would be less sensitive to the dirty air coming off the car in front, so you should be able to get close. Your car wouldn't be so affected by what was coming off the diffuser of the car in front. This was one of the ideas of the Overtaking Working Group, which also reduced the rear wing size and ultimately produced the DRS system.
The front wing idea didn't work from an overtaking perspective; it wasn't very obvious because Pirelli tyre degradation and DRS contributed to a significant increase in overtaking anyway post 2011. It did make the cars faster though.
What makes it hard to follow another car is the net level of downforce. If the car in front has more downforce it creates a bigger hole in the air and more disruption for your car.
But that means with high downforce cars there will always be a problem following other cars. Looked at another way, it means that there is not really an answer to overtaking if you want the cars to be very fast through the corners. The only way to do it is to artificially increase the downforce on the car behind in corners (the moveable front flap idea of a few years ago), or reduce it significantly on the straights (which is what DRS is today). The problem with these systems is that there are a lot of fans who don't like them and think that they take away from the driver's skill.
This is something that the rule makers and teams are wrestling with now. The call is for cars that are 5-6 seconds per lap faster than now, but also for cars that can follow each other closely through the corners to initiate an overtake. To make a car that much faster it will have to come from downforce and from faster tyres.
To get that kind of lap time gain will need a much more powerful rear wing and a larger diffuser, both of which will create a larger hole in the air for the car behind. A wider car with a wider front wing and a significant reduction in weight will also be needed.
At a fan event on Saturday night in Montreal, there was widespread approval for the idea of cars whose downforce is mainly generated in the floor, with small wings that are only used for putting stickers on and much gripper tyres putting the emphasis on mechanical grip.
The biggest external factor is the track layout; there are some tracks that promote good overtaking very time and some that do not. Shanghai, for example, sees over 30 normal overtakes a race plus over 40 DRS overtakes. Austin is heavily slanted towards DRS overtakes, with 16 versus just two from normal overtakes in the 2013 event, for example.
Things which spread the field out, like slow chicanes, tend to disrupt overtaking.
The FIA, Bernie Ecclestone and the teams are currently aiming to have a sensible plan for re-imaginging F1 cars from 2017 onwards in place to put to the FIA World Motor Sport Council on 9th/10th July.
What do you think? What kind of F1 cars would you like to see in 2017? Leave your comments below
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