Rally / 31 July 2013
MAKING THE HONDA CIVIC A WTCC WINNERFirst season, first win, two pole positions, fastest lap and multiple podiums: the remarkable results already garnered this season by the Honda Civic WTCC cars speak for themselves. The cars are built and operated by JAS Motorsport, the Italian race car team who have been Honda?s European motorsport partner since 1998. WTCC represents the pinnacle of touring car racing technology, as it?s a category that faithfully continues to utilise cars that the public watching at home will recognise.
Andrea Adamo is Chief Engineer for WTCC at JAS and the ?father? of the Civic chassis design. With a successful 20-year record in race car design and aerodynamics Adamo has nurtured the Civic from drawing board to Victory Lane. Here he explains the regulatory limits of the FIA rules and highlights the engineering philosophy that is winning races in this very competitive formula.
?I believe that the current regulations are a good mix between a road car and a race car and allow a well-engineered race car to be created with sound mechanics applied. I like very much this formula. They have been in place for a number of years so the major interpretations have been agreed. It was still necessary to go to the FIA and get clarification of some of our design concepts before we started to fabricate components. I am very much an old style engineer and try to keep the whole chassis concept in view whilst we are designing specific areas. For the Civic I produced large half-scale drawings of the car and then one starts to focus on specific areas but within the whole chassis package.
?The best performing chassis is certainly the best compromise. It is not possible to ignore any sector in the design, power, weight, handling, drivability, aero; it is not really possible to put percentages on which area is more important. The regulations restrict the aero more than the suspension so you spend more effort on the suspension for more results. Even serviceability has to be considered. Is it possible to change the engine quickly or in reasonable time at a circuit between qualifying and the races? My policy is to visualise the car at all stages of design so that I can feel the balance of all these factors as we bring it together.
?Obviously some regulations limit the options available. For example, as the regulations are very strict on brakes, everyone has more-or-less the same brake system and size - so that takes care of itself. Yes, we can improve the cooling airflow as much as possible in our design, but that?s all really. For the chassis engineer, making the tyres work properly is the main concern. Can we get heat into them quickly? What suspension settings make the tyres work best? And, of course, what works during the races?
?The Honda engine is developed by Honda R & D in Japan so our responsibility is the correct installation, the right position in the chassis within the rules. Then there is all the many ancillary elements, fuel system, wiring looms and components, exhausts positions and- as it?s a turbo engine- the total cooling system. This is not just airflow into the coolers but evacuating the air pressure from the engine compartment. There are rules that preclude closing some holes and opening others. This is typical of the WTCC limits which can give good challenges to the designer. We took an early mock-up chassis to the wind tunnel and worked out the right starting point for this, and also how to change the road-car elements of drag and lift so that we could get downforce on the front and rear end.
?As the cars use a lot of kerbs in the close racing of WTCC, our chassis design needs to be tough. This means that we need to make wishbones strong without adding weight, and ensure strong shock absorbers which give us as much adjustment as possible in both height control and damper settings. Our transmission choice was based on our experience of the supplier and the control that we know it gives us. There are advances being made in this area, too, so we need always to be aware of what is available on the market.
?Today electronic data is available from all areas of the car ? just like roadcars which store performance data for the service system, we collect data whenever the car runs. It is important to go testing with a plan, so that you find out exactly how much each alteration affects the car.
?Having an experienced driver always makes this a quicker process. Each time you alter geometry just the slightest bit and the driver needs to tell whether it?s a better drive and the data needs to show that that the tyres are working harder and the times are quicker. The watch never lies! Collecting data is good, but the important thing is understanding and interpreting that data to benefit the car. Being a traditional type of engineer from the mountains I am always challenging the data to find the right answer.
?One simple analogy is the story of a scientist who was studying frogs and put a frog down on his desk, commanding it to ?jump?. Obligingly the frog jumped, and the scientist recorded the data that with four legs the frog jumped on the command. He then cut off one of the frog?s four legs and repeated the command. The frog jumped again and he recorded the data that with one leg cut off the frog still jumped. A second leg was removed and again the frog jumped on command. The data recorded that with two legs missing the frog still jumped. This was repeated twice more and then the poor frog without legs was placed on the desk and ordered again to jump. Having observed the failure of the frog to jump this time, the scientist recorded the data that having removed four legs from the frog it had lost its hearing!!! Ok, we say data is important but at the end of the day a man is reading and deciding what that data says.
?Aero is important in WTCC cars and we have seen slipstreaming in races as important. There are FIA limits to what can be altered, but we have a solid package now. After Macau we took the complete car to a wind tunnel in Japan and we proved a lot of things and found out more things that have helped us so far this season. Weight is one of the penalties we get with good lap times and race results from the organisers so we try to make the car under the weight limit and then we can move some of the weight around the chassis for different circuits to help with road holding.
?Designing race cars is a complex science where you are working all the time with just a small amount of changes possible. If the car is competitive right from the start you still only have tiny areas to try and alter within the rules. I said earlier that I really like this formula - that is the challenge to an engineer, how to go faster every time!?