There aren't many people who find Audi's brilliant RS4 too slow, but MTM's supercharged version is a captivating car that adds a serious amount of power and torque with no apparent downside. Roland Mayer didn't expect many RS4 owners to lay down $40,000 for his supercharger conversion, which was really developed for the R8. To his surprise, several jumped at the chance to have 540 hp. Those who also had R8s on order were so pleased with their boosted RS4s that they didn't hesitate to arrange for their new R8s to be fettled too.
Driving the R8 can quickly lead to the conclusion that Audi's first mid-engined sports car could easily use another 120 hp or more. This is a car begging for MTM to unlock its full potential. MTM took delivery of its white R8 in the spring of 2008. As soon as the conversion was finished I was in the hot seat, which was the day before it made its public debut at the Sport Auto Tuner GP.
While the R8 chassis can take more power than the 420 hp it leaves Ingolstadt with, it's always the mark of a good tuner to shore up any weak points. On the other hand, if a car is already well balanced (like the R8), power gains must be matched with improved suspension and brakes to maintain that fine equilibrium. MTM has honed this art to perfection and the R8 R thunders down the road that much faster, engine still in perfect harmony with chassis.
In standard form, the four-cam Audi motor is strong down low, thrusting in the midrange and positively manic in the last 2000 rpm of its wide rev band. The MTM supercharger doesn't alter this character in any of these respects, just adds 25 percent more power and torque everywhere.
This lusty engine could not possibly work with a car that didn't have four-wheel drive. Despite having nearly 8000 rpm before hitting redline, the R8 R quickly runs out of First gear. Second disappears only marginally more slowly; trying to deploy this kind of thrust through just two driven wheels is almost unimaginable.
Third and Fourth gears are ideal for overtaking or joining a fast-flowing autobahn. Cars that appear to be closing fast when joining the autobahn soon drop back as the throttle is firewalled. This is a real warp-speed experience in terms of forward thrust.
The R8 R posts impressive numbers: 0-to-60 mph takes just 3.9 seconds, 104 mph is passed in 12.5 seconds and-unhindered by the factory speed limiter-it will charge up to 195.7 mph. For comparison, the corresponding figures for the more expensive Porsche 911 GT2 are 3.7 seconds, 11.2 seconds, and 204.4 mph.
Beyond sheer performance, an important dimension the MTM R8 R adds to the stock R8 is a seriously sporting sound track. The V8 rumble is heard in the standard car, but it's uncommonly well insulated for a mid-engined machine. Compared to a Ferrari or Lamborghini, the R8's cabin is positively quiet and limousine-like, giving it the long-distance legs its Italian rivals can only dream of.
The freer-breathing exhaust of MTM's creation-with its four 3.5-inch end pipes-creates more of an thrilling bark for occupants and bystanders alike, as addictive as the thrust that accompanies it. The counterpoint is that these sporty pipes have been designed to drop the decibel backs at cruise, courtesy of butterfly valves that open under pressure.
Apart from having a dry sump and a different intake manifold system with two (rather than one) airflow meters, the stock R8 motor is identical to the RS4's. This makes enough of a difference to the MTM conversion, however, that a peak of 560 hp at 7750 rpm (with 428 lb-ft at 5500 rpm) is possible. This compares to 540 hp at 8220 rpm (and 412 lb-ft of torque at 3700 rpm) for the RS4.