Factory backed motorsports programs are often justified on the premise that racing improves the breed. Theoretically, putting production-based cars through their paces at the racetrack ultimately benefits the quality of the cars we drive on the street. While traditional methods of testing usually sort out the bulk of real world engineering flaws, racing quickly finds the weak links in the high performance realm. If you own a fifth-gen Camaro, rest assured, racing has improved what you drive on the street.
When the latest installment of the Camaro was introduced in 2009, there were never any doubts that it would eventually end up on a racetrack. By 2010, those predictions had come to fruition. That year, Stevenson Motorsports, partnered with Chevrolet, began campaigning the Camaro in two very specific flavors in the GRAND-AM series. The Camaro GT.R, fabricated by Pratt & Miller for the Rolex GT series, was a purpose-built tube-frame car that wore a Camaro skin. The tamer Camaro GS.R, fabricated by Riley Technologies, was the weapon of choice for the production-based Continental Tire GS class. While both appeared very similar, beyond its visual appearance, the GT.R had very little in common with the street Camaro. The GS.R, on the other hand, was a production-based racecar that shared the bulk of its components with the streetcar. The GS.R was also eligible to compete in the European GT4 class in world competition, and the SCCA's World Challenge GTS class.
While the GS.R was labeled as "production-based,"it must be pointed out that anyone with a desire to go racing couldn't simply walk into a dealership and purchase a road-going Camaro, add a roll cage, and hit the track. The GRAND-AM business model, over the years, has been to partner with approved constructors and suppliers to build and support the cars for the series. Their vision with the GS class has been, since its inception, to encourage race competition of standard volume-produced cars sold domestically to demonstrate their quality and reliability. They also seek to promote drivers, manufacturers, and other participants.
As the sanctioned builder, Riley begins the fabrication of every a GS.R from a bare unpainted chassis commonly referred to as a "Body-in-White."They structurally optimize the chassis by seam-welding the entire body and installing a roll cage as specified by the rules. They also install an FIA approved seat, 6-point harness, and an engine oil and differential cooler. Teams ordering a GS.R also have the option of using approved carbon fiber body panels. There is also a list of optional equipment that Riley can provide at an additional cost. The base package will set a team back roughly $225,000 for a complete rolling chassis.
In terms of propulsion, the LS3 is the only engine allowed. As with the chassis, the engine preparation is also done by a licensed vendor. Concord, North Carolina based CRD Engine Development is the designated supplier. As dictated by the rules, CRD starts with a stock crate LS3. They replace the OEM pistons with forged units yet retain the stock compression ratio. As a measure to increase durability, valve springs are also changed due to the additional stresses. Beyond that, they still use a stock intake, and exhaust manifolds, and each engine is sealed to prevent any further tampering. The gearbox is also an off-the-shelf item. All the GS.R's come with the 6-speed Tremec TR-6060 manual box. It is kept in its stock configuration right down to the gear ratios. They also use a stock differential housing yet are fitted with an OS Giken limited slip differential, which allows teams a broad range of adjustability.
While the general spirit of the GS.R is to be compliant with the rules as much as possible, every team finds the grey areas that they can massage to improve things, yet stay within the rules. Stevenson Motorsports lead mechanic, Grant Ford points out, as an example, "we've done a lot of research and development on the ABS module. Bias ABS settings are pretty much customized to each individual driver. We've also done some research on the gearboxes and clutches. Also, when we first started running this car, we were blowing axles in the rear as if they were free. We had to research and experiment with such things as our ride height, different CV joints, grease, and cooling, to get our rear axles to survive. You have to stay within the rules, but you have the grey areas within those rules."Team manager, Mike Johnson also adds that, "Our car came out before the ZL1, so there were a lot of things we did that we learned from. There are some things we've done and suspension problems we've solved in the road-racing environment. Some of these GM has been able to incorporate into the ZL1, and especially in the 1LE."This transfer of technology is the cornerstone on which GM builds most of its racing programs.
2013 marks the fourth year that the Stevenson squad campaigns fifth-gen Camaro's. They double up with one GT.R in the Rolex GT series, and a GS.R in the GRAND-AM Continental Tire Sports Car Challenge series. John Edwards and Matt Bell return as the drivers in the No. 9 Camaro GS.R. Edwards is also the full time driver in the GT.R. As in previous years, the season kicked off on the banked ovals of Daytona. With a fresh car, the team was hopeful for a solid start to the season. However, Daytona is a track that presents a unique set of obstacles for teams. The combination of the banking and infield road course challenge teams to achieve a balanced setup. With a limited amount of track time, dialing-in a car can become a make-or-break situation leading up to race day.