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.
The supercharger conversion uses a variation of the highly efficient, Swedish-made Lysholm Technologies twin-screw compressor. Boosting at just 8 psi, this bolt-on conversion takes four days to fit, but doesn't require lowering the compression ratio. One of the benefits of this supercharger is the low mechanical drag it imposes on the engine. Both the sharp throttle response and free-revving character remain unsullied, its explosive power delivery simply enhanced.
The intercooler arrangements are similarly expeditious, with a Swedish-made Laminova intercooler providing the charge-air temperature control. This is a self-contained, water-cooled system built into the intake manifold between the supercharger and cylinder heads.
The advantage of this configuration is an extremely short-flow length, with no long pipes running around the engine, so the chances of pressure-drop and the loss of charge pressure are minimized. An additional oil cooler sits in the side of the engine bay, fed from the intake behind the decorative carbon blade.
Speaking of cooling, the stock rear window has given way to a plexiglass one, with a vent in it to help heat escape. This has the added advantage of saving 11 pounds in a critical area.
Outwardly, the elegant MTM alloys (9x20 and 11x20 with 245/30 and 315/25 Michelin Pilot Sport Cup tires) are the major visible clue that the R8 has been tweaked in any way. H&R springs drop ride height by 0.6 of an inch in front and 1.2 inches at the rear. This arrangement works fine with the factory magnetic ride dampers. Grip levels are now on a different plane thanks to the lower center of gravity and the sticky Cup tires.
A carbon front lip spoiler, side blades, rear underbody diffuser, and side skirts with intakes in front of the rear wheel arches might also give the game away. The side skirts are similar to the ones on the factory R8 V12 TDI concept car. The small red "R" after the R8 badge on the tailgate is admirably restrained. The sharp-eyed should also notice the big Brembo 15-inch front discs with eight-piston calipers. The rears are standard: 14-inch discs with four-piston calipers.
While the R8's interior is plush, the big, comfortable seats are also heavy and not totally supportive for track work. Mayer felt that just dropping in standard lightweight race Recaros would have been a cop-out, so he designed something a bit special to match the white exterior paintwork and carbon trim.
The resulting seats are based on lightweight carbon-fiber Recaros, but white leather-covered padding only appears where the body needs support. Aesthetically, the upshot is a cross between a panda and a Star Wars imperial stormtrooper, but it's unique and does the job perfectly in terms of comfort and location while driving fast.
Where the stock R8 rides with real suppleness, even at low speeds, the MTM car has a firmer edge, but pick up the pace and the more rounded that edge becomes. Importantly, at its worst, it never borders on uncomfortable-even over short, sharp bumps at town speeds where it is comparable to the latest Porsche GT3 RS. At its best, when going quickly, it's only slightly firmer than standard: impressive, considering the lower stance and bigger footwear. Avoid the suspension's sport setting though, unless you're on a racetrack.
The R8 has superb steering and the R8 R is even pointier, but the good thing is that the balance remains. It still has the same mild, stabilizing understeer that can be neutralized progressively and then turned into a gentle drift on the limit before it develops into benign oversteer, so long as steering and throttle inputs are delicate and linear, and that's with the ESP on.
The Tuner GP sorts the men from the boys. While the mighty Porsches once again triumphed in the GT Class, the MTM R8 R wasn't far behind the TechArt and Cargraphic Porsches that snatched the first three spots. Its lap time of 1:10.528 was easily the measure of a factory Porsche GT3 RS and just 1.277 seconds behind the Cargraphic GT3 RSC 4.0. For a totally docile mid-engined supercar that can be driven to the shops yet will stop crowds like no Porsche short of a Carrera GT, this is a mighty achievement.
MTM R8 R
Longitudinal mid-engine, all-wheel drive
4.2-liter V8, dohc, 32-valve, supercharged and intercooled
MTM lowering springs, Audi magnetic ride dampers
Eight-piston Brembo calipers, 15-inch rotors (f), four-piston calipers, 14-inch rotors (r)
*Wheels and Tires
MTM Bimoto alloys, 9x20 (f), 11x20 (r)Michelin Pilot Sport Cup, 245/30 (f), 315/25 (r)
Carbon-fiber front splitter, side skirts, side blades, rear diffuser, and rear wing
Peak Power: 560 hp @ 7750 rpmPeak Torque: 428 lb-ft @ 5500 rpm0-60 mph: 3.9 sec.Top Speed: 196 mph