It was music to my ears when the MTM engineer turned to me and said, "We increased the power yesterday to 730 hp from 702. You're the first to try it." Poor me.
You have to hand it to Motoren Technik Mayer. The outfit may be perfectly sized to take on the current worldwide economic rigor mortis and seize upon those several thousand eternally rich and oblivious. Following the recent 553-hp MTM R8, boss Roland Mayer aimed his shop kids at the burly C6 RS6 Avant and tossed them some modified turbochargers to throw into the engine bay. Chief challenge for the new RS6 Avant is its massive mass of 4,464 pounds. How do you enhance this Monster of Momentum yet make sure it's still a docile pet that's good with children?
One sure-fire approach is to give the 5.0-liter TFSI bi-turbo V10 in the RS6 Avant 149 more horses and 100 lb-ft more torque to drastically improve the power-to-weight ratio. The standard RS6 Avant reads 7.82 pounds per horse, while the MTM surgery changes that to a mere 6.20 pounds per. While maximum torque, 479 lb-ft on the factory car, can stay flat and full from 1500 to 6250 rpm, the RS6 R begs higher revs with its 579 lb-ft full-on between 2750 and 6280 rpm. Acceleration to 62 mph improves from the standard car's 4.6 seconds to 4.3, and top speed is comfortably let out to 193 mph versus the standard car's limited 155. More muscle to hoist things around with more authority is what I'm getting at.
Another secret lies in a more strict suspension setup to keep the RS6 firmly on the right track. Rather than stay put with the stock adaptive suspension and the optional sport suspension plus which mediates Comfort, Dynamic and Sport settings via onboard software, MTM has chucked all that and drilled the chassis to accept some supremely strong, ten-level-adjustable KW coilover dampers in back and an adjustable screw plate also developed by KW for the front towers. The simple frontal setup allows an adjustment range between 0.4 and 1.6 inches lower than stock, while in back the range is between 0.6 and 1.8 inches lower. My car was set up to the minimum chop, so not so much scraping over the ground.
The ride, with the huge 10.5x21-inch cast Bimoto alloys wearing sturdy 285/30 Michelin Pilot Sport Radial X tires, was a welcome shot of terrific responsiveness at all moments, both tracks widened by an eighth of an inch at each corner using spacers. Couple this wider contact patch and stance to an increase in front-end camber by 1.5 degrees at each wheel, and the standard 2.25 turns lock-to-lock, the RS6 R drives at times like a sports car half the weight and height.
Power and torque pounce up primarily due to the standard RS6 IHI turbochargers now modified to improve maximum boost pressure to 20.3 psi from the standard boost of 10.2. Working with ITG on an all-new air filter system for the intakes, clean, cool air flows much more rapidly to feed the need.
"Under that hood," says MTM development director Michael Weber, "there's almost no room for this modification using existing alternatives." The intake tube and filter phase basically wrap around the V10 and the execution is flawless. Once all is combusted and hurrying toward the tail of the underbody, the new performance exhaust bazookas from Top Gear, attached to a re-bent exhaust from an Audi S6, boom the good news across the landscape.
In an interesting less-is-more move, MTM switched out the ample 16.5-inch front discs and six-pot calipers for its own proven 15.9-inch drilled and granulated compound stoppers with customized Brembo six-pot monoblock calipers. These units stop like nuts, but the action is smooth.
As MTM normally does more or less nothing to its interiors, I'm left scanning the exterior for signs of change I can believe in. Luckily, there's a carbon-fiber front spoiler lip and a carbon rear diffuser, both of which add to the lowered car's low-down street cred and high-speed stability out on the autobahn.
Speaking of which, I did manage to reach at least 180 mph for a long stretch or two, and the staunch stability of the RS6 R cannot quite be rivaled even by the latest Abt-Sportsline RS6 Avant. MTM always goes for more aggression in its treatments, and on a smooth highway with no speed limit, this wagon is unshakeable. If it sprouted wings on the sides it might take off smooth as silk. But for everyday driving, I'd take either the 19-inch or 20-inch Bimoto forged wheels instead of these bodacious cast 21s.
Once the next-generation RS6 variants come out in 2011 or 2012, only then will all of this goodness be available to North Americans.
Burning Fat-paring the B7 RS4 down to fighting weight
*The current RS4, like the RS6 Avant I recently heaved around Germany, always felt as though it weighed twice what it should. It was as though I was sitting on an elephant's neck, urging the beast to do-eventually-most of what I pleased. Basically, a chore.
To address my whining, and to bless the sad passing of the short-lived B7 RS4, MTM has created its RS4 Clubsport. I'm greeted by no rear seats, a bolt-in steel cage (that weighs as much as the two missing seats but pulls its weight by adding gobs of rigidity), a functioning hood scoop, large Bimoto wheels hiding substantial suspension and brake improvements, and a four-tip Top Gear cat-back exhaust. Should be swell fun even without a power/torque upgrade.
But a power/torque upgrade there indeed is. From 414 hp at 7800 rpm on the stock RS4 sedan, we leap to a superchargeriffic 542 hp way in hell up there at 8220 rpm (530 hp quoted for the U.S.). Torque shifts from 317 lb-ft at 5500 rpm up to 418 lb-ft at 4800. Sixty should be reachable in just 3.7 seconds versus the old 4.6. I'd say the stage is pretty much set.
Nonetheless, I had to ask the dicey question about how much weight MTM pulled out. Technical know-it-most Michael Weber looked at the ceiling, mentally assessing the kilograms ripped forth, and estimated thus: "Right away we probably removed 200 kg, and that was before doing anything special." As I suspected, weight removal on an Audi is simple work. That's 441 pounds right off the bat, so curb weight plummets from 3,957 pounds to a svelte 3,546.
I sit in the sensational Recaro Pole Position seats and take it all in. Feel in the cabin is truly that of a pilot's cockpit. The combo of the tremendously supportive front seats, missing rear seats and Wiechers half roll cage awakens the butterflies in my stomach.
Hit start and there's a big difference in presentation of credentials, even at idle. There's only a little NVH stuffing left in the front wall and the 4,163cc V8 engine sounds fantastic, as it should. A Lysholm twin-screw compressor clamps onto the top of the engine like an alien on John Hurt's face, space issues necessitating that fetching hood scoop. As I accelerate, the tight feeling of all movements and actions seems utterly new to me. After only a short bit of road, I have to say out loud that not only is this the best Audi I've driven, it's one of the best performance cars period.
Certainly, throttle give-and-take is aided by the 8.7 psi of boost pressure from the supercharger, but I also wondered why exactly they didn't pump it up even more-maybe 12? Weber tells me it was a conscious decision not to open the engine and lower compression. As it is, max pressure is up in the highest revs and I delight in the 8200-rpm shift points that are almost required for getting the most out of the car. Happily, below 5000 rpm the RS4 Clubsport is a solid everyday driver on city streets.
A 270mm single-mass steel flywheel designed in-house couples with a very strong pressure plate and friction plate supplied by Fichtel-Sachs. The system is smooth as can be, not as rattle-inducing as many single-mass setups. The gearing here is modified only slightly from the RS4 factory spec, with slightly longer second and third gears, and a final ratio lowered to 3.89 from 4.11. Holding gears longer-especially second and third-is a nice upgrade.
The Clubsport suspension, as it's called, comes from a tight relationship with KW wherein MTM acts as a chief beta tester. The dampers are adjustable for pressure, rebound, and height via an external valve, and paired with racing springs. It's stiff all right, but more responsive than just bang-you-up stiff. In the set calibrated for my drive time, the Clubsport sits 2.4 inches lower than the original article. And what a damned difference it makes in every dynamic sense.
For now, I'm riding on 9.5x19-inch gravity-cast Bimoto wheels with a 30mm (1.2-inch) offset at each corner, but MTM plans to offer a curious set of forged 9x20-inch lightweight racing wheels with the same offset. The lower stance, wider track, and one degree added negative camber all combine to make the steering feel slightly thick and radically on-center, but the fat RS4 steering wheel feels good in the hands.
Then, of course, the high revs required to wring the best from it all make for a sensational song from the exhaust. The sound is smooth and big, just the way I like my Germans. Thanks to Bessie that the front brakes use dimpled 15-inch discs from Performance Friction in the States. These big steel discs with eight-pot fixed calipers allow prolonged stretches of late braking, handily reeling in all of those thrusting revs. Bloody, square-on fun.
Get yours for just around $70k for all the upgrades mentioned here (no rollcage for North America though, sorry), on top of the base MSRP. It's so worth it.
MTM RS6 R Avant
Longitudinal front engine, all-wheel drive
5.0-liter V10, dohc, 40-valve. Twin IHI turbochargers (20.3 psi max boost) and two large intercoolers with special ITG air filter and high flow-through ducts, quad-tip Top Gear stainless steel exhaust modified from Audi S6 system
Six-speed Tiptronic S automatic
KW front adjustable screw plates, adjustable rear KW dampers and springs
Six-piston Brembo monoblock calipers with 16.0-inch cross-drilled MTM rotors, braided stainless steel lines
*Wheels and Tires
MTM Bimoto, 10.5x21Michelin Pilot Sport Radial X, 285/30
Carbon-fiber front lipand rear diffuser
Peak Power: 720 hp @ 6360 rpm
Peak Torque: 579 lb-ft @ 2750 rpm
0-62 mph: 4.3 sec.
Top Speed: 193 mph
MTM RS4 Clubsport
Longitudinal front engine, all-wheel drive
4.2-liter V8, dohc, 32-valve. Lysholm twin-screw supercharger, Top Gear cat-back exhaust with throttle bypass, MTM software
Adjustable KW dampers and coil springs
Performance Friction rotors, eight-piston Brembo aluminum fixed calipers (f), single-piston floating calipers (r); stainless steel braided lines
*Wheels and Tires
MTM Bimoto, 9.5x19 Continental ContiSportContact 3, 275/30
Aluminum hood with reverse air scoop
Optional RS4 leather interior with Pole Position seats, rear seat delete, WiechersSport roll cage, four-point harnesses
Peak Power: 542 hp @ 8220 rpm
Peak Torque: 418 lb-ft @ 4800 rpm
0-60 mph: 3.7 sec.
Top Speed: 186 mph