Sci-fi writers are obsessed with the idea of opposite dimensions. A character in one dimension is the consummate good guy. Fighting for justice, he's a peaceful warrior at heart, always on the side of righteousness. In the opposing dimension there's the villain, the scoundrel, Spock with a goatee. Aside from subtle differences in facial hair, writers tend to make the characters look the same. They apparently lived similar lives that brought them to the same point in time and space where their respective dimensions overlapped through a temporal rift or a man-made portal. At some point, the two opposites must battle it out to save or enslave humanity. Generally the good guy wins, but who says our perception of the universe works in every dimension?

In a blistering hot Southern California Canyon we let two polar opposites like this duke it out for superiority. Both cars are examples of GMG Racing's WC Tuning program. Running a three-car team in World Challenge Racing has led GMG to develop its racing parts for use on customer cars. Everything from suspension to exhaust has made the transition from the track to serious street performance.

GMG focuses the majority of its attention on suspension tuning. On the track, adjustability and consistency are key to fast lap times. Adjustability is obtained by replacing Porsche's fixed-length linkages with fully adjustable pieces that allow for both static and kinematic geometry tuning. For consistency, GMG replaces all the soft rubber bushings with spherical steel bearings. Ridding the suspension of deflection ensures that everything stays were it was intended to be under heavy loads.

The black GT2 uses factory springs and dampers, while the white GT3 has attained the next level with Eibach springs and Moton adjustable dampers valved to GMG specs. Both cars use GMG anti-roll bars front and rear that allow fine-tuning the handling balance. The GT3 also uses Porsche Motorsport uprights used on Rolex Series cars. The recalibrated units alter the suspension's roll-center, changing lateral weight transfer for more aggressive cornering.

Readers should be warned that most of the suspension parts found on these cars aren't for the average guy just looking to blow some money to impress his neighbors. These are race grade parts that require professional install, set-up and maintenance. If you spend as much time sitting on the Starbucks patio staring at your 911 sipping your Dopio Machiato as you do driving it, these parts aren't for you.

Something everyone can appreciate, however, is exhaust modifications. The GT3 uses GMG's sport center section that not only adds a few horsepower but shaves 12 pounds of weight. It is completely emissions legal and even works in conjunction with the car's Sport button. The GT2 is a little more involved, the exhaust manifolds replaced with free-flowing 3-into-1 headers using F1-style merge collectors in front of the turbos. Downstream is GMG's WC titanium sport exhaust, which uses a proprietary crossover section. GMG is currently trying to patent this novel design. Both systems add a noticeable amount of anger to the cars' voices without overpowering the passengers inside.

For the real power bump, GMG worked with GIAC to develop software that works in tandem with the other mods. The GT3 gains a modest but noticeable 18 hp and 21 lb-ft of torque. The monster GT2, on the other hand, rips off 680-hp and 700-lb-ft runs on the dyno. Apparently the car was able to run up to 695 hp and 720 lb-ft, but in the interest of mechanical preservation it was dialed back slightly to keep the engine internals where they belong-inside the engine.

It may sound like these two cars have similar manners. Sure, the GT2 has more power and the GT3 seems a little more developed in the suspension department, but only incrementally. Kind of like two fighters, one being slightly bigger and the other having better technique. Both have their strengths, but neither a clear advantage.

Enjoyed this Post? Subscribe to our RSS Feed, or use your favorite social media to recommend us to friends and colleagues!