Four chassis with backbones from different race car manufacturers. Three different approaches to engines. Vastly different software engineering and styling. But how different are the Grand Touring Prototypes (GTP) from Acura, BMW, Cadillac and Porsche from one another? A couple of drivers that now have experience in more than one — Tom Blomqvist and Jenson Button — have some insights to offer on that question.
“Surprisingly, not as much as I actually first anticipated,” answers Blomqvist, who spent last season at the wheel of Meyer Shank Racing’s Acura ARX-06, but is now the third driver in the Whelen Engineering Cadillac Racing V-Series.R. “I guess the regulation is quite confined, and that brings these things into a relatively small window.
“There are pros and cons of both cars. I have felt a difference on the small details — how they drive, and maybe where one is better than the other. But I think the biggest difference is actually more the software and the driver interface. And in terms of the basics, like your dash and the different tools you have inside the cockpit to make changes to the software. Obviously, all the engineers have their different way of doing things, so that’s probably the biggest difference. And the biggest thing I have to get used to — where everything is, and which direction to go in terms of changing things to affect the car.”
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During the DPi era, it was generally acknowledged that the different makes had different strengths, i.e. the ORECA-based Acura chassis worked best with a low ride height, while the Dallara-based Cadillac could tolerate being run a bit higher and was better on bumpy circuits. The differences in GTP cars appear more subtle and no make has appeared to have an affinity for a particular style of track yet. But the drivers have picked up on the cues the cars have offered.
“I think the Acura was a very stable, solid car on the way into the corner. You could really attack the entries, and the car would behave relatively well,” Blomqvist says. “The Cadillac’s known to having good traction, and you definitely feel it — the Cadillac really drives off the corner nice and very smooth. It’s obviously a naturally aspirated engine, which probably makes your life a little bit easier. The Caddy’s very nice to drive out of the corner and maybe just a bit weaker on the way into the corner. So it’s all give and take.”
Button, who’s currently hovering in two manufacturers’ worlds while driving the No. 40 Acura ARX-06 for Wayne Taylor Racing with Andretti for the Rolex 24 At Daytona before he returns to Hertz Team JOTA’s Porsche 963 in the World Endurance Championship, stops short of offering direct comparisons. But the 2009 Formula 1 world champion, whose first GTP experience came in JDC-Miller MotorSports’ 963 at Petit Le Mans last October, says there are some real differences in the way things work with the two cars.
“The biggest thing is how they use the tools, because I think all manufacturers pretty much have the same tools, they’re just labeled something different,” Button says. “They have the same tools to play with, but it’s how they use those tools and which tools they prefer. So it does take a bit of time to get used to.
“Everything on the steering wheel is completely different as well. The go button, the throttle and the brake are the only things that are the same, so it does take a while. I was testing in Bahrain last week in the other one, so trying to wrap your head around the steering wheel again and the functions and what you actually want from the car and the switches that work for you, does take a bit of time.”