Since 2013 the British Touring Car Championship has run to the NGTC rules. The next generation touring car concept was introduced to control the costs of competing in this form of racing that had hit multi million pound budgets under the previous S2000 rules.
The BTCC has long been one of the world's most exciting and competitive championships and has attracted manufacturers and top drivers from around the globe. It has a massive following and aside from F1, it draws the biggest crowds both at the circuit and on TV.
NGTC basically defines a lot of the running gear of the car to a kit of standardised components. Only the bodyshell, engine and the body styling kit can change between cars/teams. The engines are turbo charged 2 litre 4 cylinder types with equivalency rules to ensure parity of performance.
So the room for engineers to find performance is severely restricted. However because the competition is so close (often only tenths of a second covering most of the grid) small detailed improvements can make big differences to grid position.
BTCC teams range from very professional manufacturer teams to very enthusiastic amateurs with a ton of volunteer help. When you are doing any serious race car engineering work it's very important to know what you are working from. Touring cars tend to be hand built and parts made up ad hoc as the cars come together so knowing exactly what you have can be a problem. In F1 for example every single part will be CAD modelled allowing you a lot of possibilities for analysis and simulation.
So I think it's really important to try and understand what you have and so part of that is to build CAD models where possible in the case of my current project I've assembled CAD models of all of the standard kit components to begin with. The team have a limited budget but also practical requirements for spare parts and the desire to try and keep up with developments.
The flat floor at the front creates an aerodynamic splitter element and is one area that can be changed by the teams as it must fit an offset of the front bumper/air dam plan view silhouette. As with all race cars you are looking to reduce the weight and keep it as low as possible. This team needed spare floors and at the same time we've reduced the overall weight and made the floor area larger to the extent allowed by the regulations. As the front air dam creates a high pressure area in the front of the car and on top of the splitter with a reduced pressure underneath you end up generating down force. As down force comes from the pressure difference between top and bottom of the splitter multiplied by the area of the fool that that pressure acts upon, the larger the area of the flat floor the better. In this case we've added about 1300 cms Sq so hopefully that and 3kgs less weight will make for very cost effective performance improvement.
The other part of this first stage of upgrades is to redesign the body kit to further reduce weight and decrease drag and increase down force. We don't have the budget currently to conduct wind tunnel development and whilst we have CFD capability without the budget to scan the cars shape and create CAD data for this we can't make much use of it. So we are using experience and common sense to try and make improvements in the area.
As the car is currently 3 kgs over weight and front weight balanced we are aiming to reduce the weight of the front bumper, wings etc and then if required to make up the minimum weight with ballast low down in the rear of the car. As the cars race performance is dependent on how they use and abuse the tyres, balancing the front to rear weight split to equalise tyre use is likely to be important for overall race performance.
