2004 MTM Audi RS6 Avant performance review: classic MOTOR

It’s like giving Spider-man a bungy cord, the Terminator a gun licence or Kylie Minogue butt implants. We thought one thing Audi’s steroid-fed muscle car RS6 didn’t need was more horsepower. We’ve been proven wrong.

This feature was originally published in MOTOR's October 2004 issue

Sydney-based Audi and Mercedes tuner TCCA Motorsport is the local outlet for the German-made horsepower-helper range of MTM, which recently turned its tuning attentions to Audi’s RS6.

At 230 thousand dollar coins, entry into Club RS6 isn’t cheap, but offers privileges: like exclusivity. And, with a twin-turbo 4.2-litre V8 good for 331kW and 560Nm, it’s a fair bet most of the 30-odd RS6 owners in Australia would be happy. So, it’s ironic that the current TCCA customer’s need for improvement came about because at open-track days, two other RS6s were giving him the hurry-up.

Calling on the MTM arsenal, TCCA currently offers five stages of RS6 upgrade for a wide range of budgets, each stage a building block in a continuing, complementary path.

Remember that when we tell you the top-spec stage five changes turbochargers, cylinder head gaskets, exhaust, ECU, fuel system and gearbox ECU for a serving of 418kW – and a bill of $44,200!
Turn it down one stage, and before you stands a stage four beastie quoted at 393kW.

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Stage one leaves power at 331kW. It’s actually a $3100 MTM-modified Motronic ECU that eliminates the factory 250km/h speed limiter without affecting anything else. MTM says the RS6, unimpeded, will run to 295km/h.

Might as well go straight to the $7700 stage two, though, including the speed limiter defender and a total retune of boost pressure – from 13psi (0.9 bar) to 21.7psi (1.5 bar) – fuel and ignition curves. This hints at the RS6’s potential, with power jumping 37kW to 368kW. Better still the tonne of extra torque, up 130Nm to 690Nm!

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Stage three tips in another 6kW. Granted, its price tag increase of $9170 is high, now up to a stage one, two and three total of $16,870, but it does include a rather fine stainless steel, smarter-than-average mandrel-bent exhaust system. The kit includes piping from cat converter to twin-dual tailpipes.

It also incorporates an engine-bay-mounted module that reads fuel pressure and turbo boost or vacuum to regulate two butterfly valves in the outer two pipes of its quad-tip exhaust system. At idle and low speed, these valves are closed to keep noise (and profile) low, but under load and boost pressure, they twist open to uncork backpressure.

Loud? It’s difficult to pick as being anything but standard while cruising and MTM has conspired to reinforce that illusion with the rear garnish panel.

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Compare the MTM with a standard RS6 exhaust (oval tips, oval bumper cutout) – not only are there quad tips, but larger cutouts courtesy of complete replacement garnish panels in the same latticework pattern. Sneakishly smart!

Prefer full stealth mode? Then go for the $1500-cheaper, same-as-standard dual-pipe exhaust and no-one will ever know! But give it a bootful and the rumbling V8 cracks to redline so sweetly it licks your ears like a puppy, with more immediate urge and loads more mid-range power and torque.

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Stage four’s price tag is a highly significant $27,850. Yes, it’s $11,080 more than stage three, and yes, there is more power: 19kW more, totalling 393kW, and up 62kW from stock. This adds two metal high-flow catalytic converters, an uprated fuel pump, matching fuel pressure regulator and a modified gearbox.

MTM only ‘recommends’ an upgrade in the Audi five-speed Tiptronic gearbox, for stage one to three, but deems it necessary for stage four. It’s simply an ECU tune that allows for a few hundred extra rpm in gears, harder shifts under throttle, and softer shifts while cruising, all down to a rewritten gearbox ECU. On its own, it’s a $640 option.

Finally, a set of blue silicon boost hoses and clamps, at $1800, ensures no leaks.

Visually obvious the mods aren’t, but the RS6 is all about subtle. Even the optional $760 H&R coil spring kit is just a mild 10mm drop.

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So how does it go? Bloody marvellous! Under a heavy boot, the extra boost whistles and turbos spool up a few hundred rpm earlier to deliver a mighty wallop! On full boost it’s gobs faster than the stocker; off, it’s virtually indistinguishable.

Discounting our super-quick, super-sticky PCOTY times, the stock RS6 Avant manages a 0-100km/h in 5.4 seconds. The MTM stage four-kitted version tripped a 4.6! Over the quarter, the stocker runs a 13.57 @ 167.3km/h, while the MTM Q-ship launched loads harder and boogied down to a 12.97 @ 170.5km/h! And thanks to the auto, it’s easily repeatable.

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With a hybrid TCCA/MTM/Audi parts warranty, the dubious part isn’t the issue of power, performance or quality, but value. Prices don’t include fitting (done at cost) and for a 19 percent increase in power, the stage four kit (with silicon pipes) adds 13 percent to the price.

Does $29,650 equal a 62kW gain? Whether MTM’s gear makes sense ultimately depends on how much is sitting in the bank. But this is definitely one case where more is not less.

TT = TWIN TURBO!

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A 393kW Audi RS6 not wild enough for you? Try MTM’s bimota TT with twin 316kW/510Nm turbocharged 1.8-litre fours. That’s right, two engines, totalling 632kW and 1020Nm.

With 1490kg on 19-inch alloys, try 0-100km/h in 3.5 seconds, 0-200km/h in 9.9 and a genuine 371km/h top speed. Inside is a pair of starter buttons and twin tachos.

Tuner Torque