It may look like a Mazda RX-8 and does carry Mazda logos, but is it actually a Mazda or a real GT car? (Photo: Marshall Pruett) » More Photos

Hey Marshall,

I've just started following sports car racing in America, and I was surprised to hear that the GT cars in the ALMS series and the Rolex series were different. Shouldn't a GT car be a GT car? So what's the difference between the two? Shouldn't owners of the cars be fighting to unify the rules so they can run the same car in both series?

Michael Keaveney

Michael--that's a big can-o'-worms to open up, but a great question that deserves a great answer. It's especially timely in the wake of the Indycar unification. Unfortunately, the best I could come up with was an answer by Racecar Engineering Magazine's Sam Collins, so I chimed in with my own thoughts after Sam's mad ramblings... ;-)

From Monsieur Collins:

When is a GT not a GT?

Now you see, a proper GT racer is really just a converted road car, for example the Porsche 911 GT3 RSR. Stick a roll cage in it, fiddle with the engine a bit; if you are feeling rich, you might even fit a sporty sequential gearbox. Then you go racing. It’s as simple as that, right?

Well seemingly not. The FIA's GT2, GT3 and the imaginatively titled GT4 all follow this concept but other classes stray from that a fair bit. GT1 is a little different as the cars are developed very heavily (like the Corvette C6.R) but there are still significant bits of road car involved. That for me is a GT car, based on a road car.

Grand-Am Rolex GT's on the other hand are not really GT's at all because they are allowed to use purpose built tubeframe chassis such as the Riley MkXV. So really they have very little to do with a road car. They are closer in design to a Daytona Prototype or a NASCAR than a GT.

Should the two classes unify, or at least run to a very similar rule book like in FIA GT and the ACO series? Well it would make a lot of sense, but the only way for that to happen would be for Grand Am to adopt the ACO rules that govern the ALMS, which would render the current crop of Grand Am 'GT's' obsolete. Only the Porsche 911's would survive. And please don't get me started on Daytona Prototypes!



Here's my take on things:

The two series have very different philosophies on what they consider to be a GT or prototype. VERY different. I’d love it if we had a single sportscar series with massive grids, but with the American Le Mans Series and the Rolex series, you're presented with a choice between high tech cars and a lineage that dates back to the first days of Le Mans, or a series where the cars are nearly identical and a link to the historical passions of sportscar racing are rather hard to find.

While the exteriors of ALMS GT1 and Rolex GT cars might give the impression that integrating the two series would be a snap, but the real differences, and why it’d be impossible to merge the series can be found just beneath their body panels.

If you were fortunate to see the TransAm series in person from the ‘80’s onwards, those cars had the drivetrains of whatever manufacturer they claimed to be, but other than that, the tubeframe chassis, body, electronics, and most other components were all built from scratch by racing fabricators. There were a few exceptions, but not many. You could buy a Riley chassis and put a Mustang body on it, a Camaro body on it, and later, a Jaguar body, depending on what kind of car you wanted to pretend it was. The rules called for the engine to match the body, but everything else was completely interchangeable. Doesn't have much in common with the cars coming off a Detroit assembly line, does it?