This year the red bulls famously took turn 8 at Istambul flat. I wondered about the G-force involved, the actual lateral acceleration. The most obvious answer is the G-force graphics we often see, but I am not sure of how accurate are those? They seem to stop between 4.5 and 5 Gs, and if we would believe them, braking goes over 5G all the time.
So, can we actually measure lateral acceleration? Turn 8 is a long aero corner, and this is my attempt at pulling out some very rough numbers.
I used this video from Webber's pole lap this year
http://www.mototube.pl/film/4655/flvide ... 521544.flv
to measure the time it takes. 7.4 seconds from turning in of the wheel to the wheel going straight again.
Then I used www.mapmyrun.com to make a rough trace through the racing line in a satellite picture: 530 meters of racing line, using the rubber marks to estimate turn in and turn out points.
I also used that satellite picture to measure the total turning angle: 218 degrees, but I suspect my computer stretched the image a tiny bit.
Let's take those three values at face value and assume that the corner is a perfect circumference arc, which it is not. I can work out these numbers:
Total circumference: 875.23 m
Corner radius: 139.30 m
Car velocity: 71.6 m/s (257.8 Km/h)
Fc = m v2 / r (centrifugal force)
Ac = v2 /r = 36.66 m/s2 (Centrifugal acceleration)
36.66 m/s2 = 3.74G
So I get 3.74G average. The corner is tighter through the first 3 apexes and opens up at the end, so this probably works out to very close to 4G for around 4 seconds at the beginning of the corner.
There, my puny attempt at actually measuring things with all the wrong tools. Anybody with better tools wants to improve on this? What is the (actual) maximum G we get through corners this year? Remember that Silverstone is coming, might it be there? Were there any higher (actual) cornering G forces in the past?