In this new series that is EXCLUSIVE to http://richlandf1.com/ and to my own blog, we will take a more in-depth look at F1 technologies and how different aspects of the car affect the handling and how the handling is tuned by altering the car setup.There are many different aspects to car setup. You have to find the compromise between high speed and low speed cornering grip, steering responsiveness, traction under acceleration, how much kerb you can ‘hop’, how the car handles bumps under different conditions, e.g. braking, high speed cornering, low speed cornering, traction and direction change, how the car handles under braking and general balance in the corners.
Part 1 – Tyres
In the first of a 5 part series, we will look at the tyres and they way they play their part in car setup. The tyres are the only surfaces allowed to touch the ground within F1 regulations. Formula 1 tyres run at a pressure that’s much lower than that you’d see in your average road car which normally runs at around 32-38PSI (2.206-2.620bar). They run between 17 and 21PSI (1.172 – 1.448 bar) as they have much stiffer sidewalls and shoulders. Only very small changes are ever made to the tyre pressure. This is done because as the tyre pressures are already very low, they become more responsive to changes. Having reduced pressure means that the tyre can spread out more, giving a larger contact patch, and therefore increased low speed grip. However handling responsiveness overall is reduced and more driver effort is needed to turn the wheels. It also increases fuel consumption as the tyre is squashed more, increasing friction. Tyre warm-up is increased as the inter-molecular friction creates.
Obviously there are different forms of tyre temperature. These are surface temperature and core temperature. The core temperature is the temperature of the gas inside the tyre and is the most important. Surface temperature is the temperature of the tread that makes contact with the road surface. Tyre heat is generated in 3 ways. The first and most efficient is flexing of the tyre wall. This creates internal heat. The second way is surface friction; this is the slipping of the tyre over the road surface. It produces a large amount of heat but it is quickly dissipated through the road. The final one is heat from the brakes. This is the best way to keep the tyres warm. It is part of the reason why the cars do lots of speeding up and slowing down on their warm-up laps, to get heat into the brakes which then radiate into the wheels and tyres. If a tyre gets too hot they will start to ‘blister’ this means that bubbles of built up gas appear on the surface of the tread, which then burst to leave deep pits. The worst known case of this was Spa 2011, in which RedBull seeked permission to alter their car setup before the race to give them better tyre life. The blisters are normally seen on the inner shoulder o f the tyre, like in the photo from the link below.
In F1 there are 6 compounds of tyres, 2 of which are grooved to clear water for wet weather use only. Each has their own colour logo on the sidewall.
Silver is the hardest compound, and is a dark silver to make it easier to distinguish between it and the medium compound tyre which is white.
Yellow is the soft tyre and is arguable the best compromise between grip and life.
Red is the super soft tyre and has the best grip, but the least durability.
When talking about the ‘softness’ of the tyre, what people are really saying how much friction each compound makes. Soft tyres are more pliable so have more grip, hard tyres are stiffer and have less grip. Harder tyres also mean that the molecules that make up the tyre have a stronger bond, meaning they wear less.
Then there are the two wet weather tyres, the green intermediates and the blue wets. The intermediates have a shallower tread, and more contact area which makes them the best for a damp track, and changing conditions.
The blue tyres have the smallest contact patch, but the deepest tread of all the tyres. They’re the softest compound out of all of the tyres, and overheat very quickly in anything other than standing water.
In the next part in this series we will look at the brakes and how they affect the handling of the car.