By almost anyone’s standards, Audi’s R8 with the Lamborghini-derived 5.2-liter V-10 is a fast car. The engine puts out some 525 horsepower and 391 ft-lb. of torque, which is enough to get the R8 V-10 Coupe from zero to sixty in 3.7 seconds, or 3.9 seconds for the R8 V-10 Spyder. Top speed on the coupe is said to be 196 miles per hour, which is annoyingly-close-but-just-shy-of 200 miles per hour. If you’re lucky enough to own either version of Audi’s 5.2-liter equipped R8, it’s easy to understand why you’d want to make it just a little bit faster.

Enter Heffner Performance, a tuner with a significant history of making Audis->ke14, Lamborghinis->ke44, Ferraris->ke252, Ford GTs->ke411, and Dodge Vipers->ke1404 faster, yet still docile enough to drive on the street. Their latest bolt-on package for Audi’s V-10 R8s - the Twin Turbo "bolt on" system with twin Garrett GT35R turbochargers at 6 psi - will get you 725 horsepower at the wheels, on 93 octane pump gas. That’s an increase of 200 horsepower from stock, yet the car retains its sophisticated, grand-touring demeanor.

Full story after the jump.

In Heffner’s own words, their upgraded R8 is the “most refined aftermarket twin-turbo car we’ve ever experienced,” and the tuner describes the onset of power as smooth and linear. That’s a very good thing, since we’d hate to experience a car that delivers a “harsh and abrupt” 725 horsepower, even if it did include Audi’s superb quattro all-wheel-drive system.

The exhaust note can be tuned to each customer’s expectations, which means you can have a 200 mile-per-hour R8 without setting off car alarms when you drive by. Heffner Performance sells the twin-turbo setup through its network of dealers, and each kit includes a 12 month, 12,000 mile warranty on the Heffner-built components. The company doesn’t list pricing on their website, but adding a reliable and well-sorted 200 horsepower to Audi’s R8 doesn’t come cheap. Still, if you’ve got the money to buy an R8, adding enough horsepower to get you past the 200 mile-per-hour mark seems like a reasonable investment to us.