The remarkable aerodynamic efficiency of the Opel Astra TCR is the product of over several days of wind tunnel research, and precise Opel Motorsport engineering. And this is by no accident, as aerodynamic efficiency was one of the main focal points while the team was developing the Astra TCR, which was built to compete in the Touring Car Racer Series, incase you were wondering what the TCR stands for.
To achieve this aerodynamic efficiency, the team had to find the balance between downforce and drag. It is not about maximizing downforce for optimum stability, because more downforce also means more drag, and too much drag makes for a slow racecar. Conveniently for Opel, the new, European Car of the Year 2016-winning Astra has an impressive drag coefficient of 0.272. This made the Astra hatch the ideal platform for a touring car racer.
When you compare the Astra TCR to its mass-produced twin, you’ll see that the width of the car has been increased to 1.95 meters, which is the maximum width permitted by TCR rules and regulations. The bumpers, fenders, and side panels have been modified as well.
The front splitter and rear wing are defined as standard components by TCR regulations in an attempt to minimize costs. This means that the manufacturers are allowed to fine-tune the mounting position but are not permitted to change the shape or finish. The rules and regulations also state that the rear wing is not allowed to protrude the roofline, or by more than 1,050 millimeters from the center of the rear wheel hub. A challenging feat indeed, and finding the sweet spot for the front splitter can be just as difficult.
Fortunately the team was able to utilize Stuttgart University’s wind tunnel to conduct its testing. The rolling floor allows for the simulation of up to 250 km/h, which makes it an ideal site according to Opel Motorsport’s Senior Manager Dietmar Metrich.
Metrich could not speak on the data and measurements taken during the wind tunnel testing, but he did make this statement, “we feel perfectly prepared thanks to the excellent suitability of the base model. We will only find out where we stand when the cars compete on the race track but that makes the whole thing really exciting!”