...Also adding to Heffner's reputation is that he just happens to build the fastest Vipers on the planet. Heffner Vipers own 1/4 mile records including the quickest Viper using the standard 6-speed manual (8.75 sec @ 168 mph) as well as the fastest Viper using an automatic transmission (8.26 sec @ 176 mph). Heffner-built cars also compete and do very well in the V10 Nationals, a Dodge Viper-specific drag racing. How much power are these cars making to achieve these times? Using an in-house dyno, the modified V10 engines can make 1100 rear-wheel-horsepower on 93 octane and as much as 1500 rear-wheel-horsepower on racing fuel.
Not all of the Vipers built by Heffner are necessarily this extreme. Owners can purchase a variety of engine packages to suit their budget. Naturally aspirated, supercharged, or turbocharged packages are all available, ranging anywhere from 575 horsepower all the way to 1300 horsepower. The featured car achieved 902 rear-wheel horsepower and around 957 lb-ft rear-wheel torque on 91 octane.
For this particular Viper, the list of modifications runs longer than just about any car out on the street. The basic twin-turbo package on the car includes not only the dual turbochargers, but also the addition of a front-mounted intercooler, an AEM engine management system, upgraded air filters, a modified fuel delivery system, and larger fuel injectors to name just a few. Some of the other performance modifications in addition to the standard package include custom forged pistons, upgraded intake and exhaust valves, and a three inch stainless steel cat-back exhaust system.
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