Race Car Setups: Millimetre Perfection
Written by William Stephens, Edited by Simran Kanthi
The setup of a race car is the most fundamental part of producing fast consistent lap times. They require every component to be within its useable life and every bolt to be torqued to the correct specification.
The tyre is the most essential part of the race car setup as it is the only contact with the track. This means that the contact patch must be optimised as much as possible. Part of this is done by the use of the radial-ply tyre construction, which gives the sidewall enough flexibility to move at speed and increases grip over the older cross-ply tyre construction which was used until the late 1990s in motorsport, despite its stiff and inadequate sidewall for racing.
The tyre will also need to be in its optimum pressure and temperature window on track. These numbers are issued by the tyre supplier who will provide the limits of grip to expect and how the tyre will wear from its pre-production testing. If the tyre isn't in its correct window, it can grain or blister depending upon the temperature of the rubber. Graining is traditionally when the tyre is not up to temperature and has been pushed too hard, ripping the tread from the tyre and reducing its life and grip. However, blistering is when the tyre gets too hot causing the rubber to fall off and lose its stickiness to the surface.
To determine wear on a slick tyre, a small divot called a wear indicator is added to the tyre so the teams and supplier can determine if it is wearing as it should and how much wear the tyre has undergone, which will be important for maximising lap time on track.
Suspension is configured to not only optimise lap time for the driver's preference but to also maximise the contact patch of the tyre throughout the lap. This is done with a camber so the wheel will sit upright at high-speed corners where the load on the car is at its peak. The car will be configured to a baseline setup for the track at the workshop before arriving at the circuit where it can be adjusted depending on the weather and the style of the track. .
The ride height of the car is governed by the series' regulations and the track. For instance, at a flat track like Silverstone, one will aim to have around a 10mm gap between the floor and the track, but at the undulating Brands Hatch, the ride height will be increased to prevent the car from ‘bottoming out’ and hitting the ground when unwanted reducing downforce and grip puts the drivers' safety at risk.
The tow levels on a standard RWD (Rear Wheel Drive) race car will have tow in at the rear, so the rear wheels push against each other helping the car go in a straight line and a small amount of tow out to counteract the rear and have the car drive in a straight line. The car's spring rates and preload will also depend on the circuit as on some tracks, a stiffer suspension setup will be more beneficial for lap time than a softer sprung car.
The wing levels on both the front and rear of the car can be adjusted on most formula cars, with rear wings being the main focus on GT (Grand Touring) and prototype racing. These levels are adjusted depending on driver preference and track layout, alongside the tyre and suspension setups to provide the optimal amount of grip in the corners and enough straight-line speed to be competitive against other cars. The ride height is also an important factor as a lot of race cars will have an aerodynamic floor that sucks the car to the ground, helping the car corner at speed.