It has been confirmed officially that the 2008 Viper will get a 90hp bump up to 600hp and a 25lbft torque bump up to 560lb-ft from a displacement increased up to 8.4 liters (510ci/8354cc), better flowing heads with larger valves and dual throttle bodies. The development of the engine was done with help from McLaren Cars and Ricardo. Changes outside of the powerplant are minimal, but still influential. The T56 transmission has been replaced with the new Tremec TR6060, and a revised shifter has been paired with the new gearbox. Shifts are claimed to be 18% quicker (faster than the Corvette Z06). The Dana M44-4 rear axle from the 2003 model now has a GKNVisco differential that greatly help the tires in getting grip under acceleration. One last performance upgrade was the removal of run-flat tires; the new tires remove most of the minor flaws of the early gen III models and should give the Viper nearly unmatched handling on any circuit. Another notable change is the reworking of the exhaust system, previous third generation Vipers had their exhaust crossover under the seats which resulted in a large amount of heat going into the cockpit, this was done initially to help improve the cars exhaust note, since the first 2 generations of Viper, which had no crossover, were criticised for their lackluster exhaust notes. For 2008, the Viper exhaust will utilize a new exhaust system with no crossover, reducing the heat that enters the cockpit, but still produces an exotic sound[1].
