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| Billy Johnson drove the #94 Turner Motorsport BMW M3 in the 50th anniversary of the 24 Hours of Daytona in 2012 with Bill Auberlen, Paul Dalla Lana, Jorg Muller, and Boris Said. Many Rolex races and few CTSCC races will run during or into the night. Photo courtesy of J.D.S. Photos |
ROLEX GT:
GT cars fall under two categories. Prep 1: Real production unibody cars like Porsche GT3, Audi R8, Ferrari 458, and some Corvettes; and Prep 2: Tube-frame racecars like Trans-Am or NASCAR, typically Mustangs, Camaros, BMW M3s, Mazda RX8s and some Corvettes – typically only sharing the engine and rough body shape with the production car they represent, albeit the stock bodywork with flared fenders to fit the wide 300-width tires under them. In Prep 2, you can see a production car that has struts and multi-link suspension with proper upper and lower A-arms front and rear with a transaxle.
Weighing 2,300-3,000lbs and having ~450-550hp, these cars have impressive power to weight ratios, wide 285-325 width Continental racing slicks, and significant splitters and a proper airfoil wing out back. Whether Prep 1 or Prep 2, these are “GT” racecars to the full extent with cockpit-adjustable swaybars, sequential transmissions (some aftermarket trans-axles), no power brake assist, and proper racing master cylinders and adjustable brake bias with upgraded front and rear
brake calipers. Ride height can vary from 2.5” to 3.5” depending on the rules for specific cars. I would guess a GT car would do a 1:46-1:49 at Buttonwillow.
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| The 50th Anniversary of the 24 Hours of Daytona brought the return of Ferrari with their beautiful converted GT3-spec 458 Italia. Audi also showed up with a couple GT3-spec R8s while Dodge returned with the Viper Comp Coupe. Behind the Ferrari is the staple of GT racing, the Porsche 911 GT3 which ended up winning the race. |
These GT cars are light and drive like real racecars. They are more like the highly modified “Modified” class time attack cars from a weight, tire size, and aero standpoint. While some TA cars have more power, they often retain stock synchronized transmissions so straight-line speed would be similar to the less powerful GT cars because the GT cars can shift faster.
While the Prep 1 cars like the Porsche do feel like you’re driving a street Porsche from a visibility standpoint, the Prep 2 cars often place the driver very low to the ground where the gauge cluster is in your direct line of sight. You simply can’t see! It’s a very different driving experience to drive these cars. My first time driving a Prep 1 car was the BMW M3 GTR –which had the driving position more like Prep 2 cars. I was concerned about just making it around the track, let alone racing people with this outward visibility. With time you get used to it and it doesn’t bother you but at first it is very concerning.
The sequential shifters are an awesome nice feature that will spoil you. So are the cockpit adjustable swaybars and brake bias. Like most proper race cars in motorsports, driving a car at this level spoils you with versatility but while it can help you tune the ever changing car to go faster, you can improperly tune it to be evil or outright slower; so it is a double-edged sword.
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| A crowded field of Rolex GT Prep 2 cars. |
There are a lot of dynamics going on in GT from Prep 1 running 15” brake rotors to Prep 2 running 13” rotors, to the streamlined aerodynamics of the Porsches compared to the bigger Camaros and BMWs, to the low ride height lighter cars to the heavier and higher up BMWs and Camaros which often have more torque. The lower and less torquey cars tend to drive more like a GT car than the heavier Camaros and BMWs which feel slightly like a GS car.
GT cars are often extremely refined, well developed and pleasant to drive due to all the engineering that goes into them. While they might be easier to drive than an under funded less developed time attack car, there’s a reason why the pros get paid, getting the last tenth or two out of a GT car is the difference between a win and 10th. While proper geometry changes are not attainable or too expensive to do for TA competitors, Modified class cars are quick because a turn of a boost controller makes a lot more power, or the cost for a bigger wing is a grand or two and there are not many constraints like professional racing creates.
