CADILLAC DPI V.R.: HOW TO BUILD A WINNING RACECAR

18.10.2018

In stark contrast to racing in Europe, the US-based IMSA Weathertech championship allows both DPi and LMP2 cars in the “P” category. We wanted to know all about the DPi cars so we sat down with Wayne Taylor Racing Technical director Brian Pillar and Dallara’s Antonio Montanari to find out more…

 

CADILLAC DPI V.R.: HOW TO BUILD A WINNING RACECAR

So the Cadillac prototype is a DPi. How does it differ from an LMP2 car?

Antonio Montanari: Well, the chassis itself is the same – it’s regulated by the IMSA. The biggest difference is the appearance, which is also the biggest challenge during the development of a DPi car. The DPi has to look like a Cadillac but it also needs to win. Whereas an LMP2 car is much more function over form. We spent a lot of time in the windtunnel and in the Cadillac design studio.

 

So the Cadillac prototype is a DPi. How does it differ from an LMP2 car?

How smooth is the collaboration between the both of you?

Brian: Antonio and Dallara built us a car and I get to play with it. That’s the short version. The chassis was developed in Europe, but it was up to me to develop it for US racetracks because they’re different to European tracks (Antonio: “It’s a whole different world”). I mean, take Sebring for instance: those famous bumps are very demanding on a chassis so Dallara left a lot of scope in there for me to tune the car.

 

How smooth is the collaboration between the both of you?

What was the biggest challenge during the development of this car?

Brian: We’ve been used to working with the previous generation of Daytona Prototypes and they relied much more on mechanical grip than on downforce. Developing this car was like starting with a blank slate… There was nothing for us to go on from previous years.

 

What was the biggest challenge during the development of this car?

Recently I’ve seen a lot more cars being developed virtually on a simulator than on an actual track. Was that the case with this car too?

Antonio: We always start developing any car on the simulator. We have two simulators - one in Italy and one in Indy, and it is basically a big toy. We usually try to test things both on the track and in the simulator.

 

Brian: In 2017, when we first developed the car, most of the testing was done on track to get a feel for the car and gain as much experience as we could. This year we’ve done a lot more sim work because we know the car and how it will react, so the sim comes into play more often to try out little details. Next year it’ll be even more important to us.

 

Recently I’ve seen a lot more cars being developed virtually on a simulator than on an actual track. Was that the case with this car too?

When you’re setting up a car, you always have to bear in mind the driver and their style. How do you approach this?

In our case we’re pretty lucky as we’ve been able to work with Ricky Taylor and Jordan Taylor for a long period so we know how they drive. But on the other hand, sometimes drivers just have to move with the times - downforce is so important now. There have been moments when we said, “let’s put more front downforce on the car, it’ll go faster”. When the driver would disagree and say, “but it’s already on the edge”, we would push them to try it anyway and often it would be faster. When you’re building cars with this amount of downforce, there’s a blind faith a driver has to have in the engineers when they say it will go around a corner at a certain speed - way faster than they might think it will. I think trust is the key here.

 

When you’re setting up a car, you always have to bear in mind the driver and their style. How do you approach this?

How do you evolve from the perfect car on the test track and in the wind tunnel to an actual winner?

Antonio: We try and develop it for racing as much as possible. In racing, you’re never alone on the track so we test using “dirty air”, for example, in case there is a car in front of you. You cannot lose all your downforce when a car is in front of you, because that happens constantly during endurance racing.

 

Brian: When we’re setting up a car, we have to keep in mind the changing conditions during a race. For instance, this Motul Petit Le Mans race might start in the cold morning air, become really warm in the afternoon and cool off again in the evening. These conditions change the density of the air which has a huge impact on our aero package. Dallara delivered us a car which can be adjusted quickly, even during a pitstop we can make quick changes to the rear wing or install a new nose with different settings in the front aero. It only takes a few seconds to swap a nose on our car.

 

* This interview took place before the race, and the car we are talking about actually won the race. Congratulations to the WTR-team.

 

Pictures : ©Frederik Herregods

Cookies help us deliver our services. By using our services, you agree to our use of cookies. Learn more

© 2018 Motul

Change location