Component rationalization has been a godsend for carmakers because it enables them to save money by using common components across a broad range of models. And for the consumer, there's an advantage to having, let's say, a detuned version of a flagship motor in your car, especially when the tune is essentially software based. This would enable the astute aftermarket tuner to extract the missing horsepower knowing the mechanical components have a comfortable margin to work within.
The new Audi S6 is a case in point. Its 420hp, 3993cc V8 biturbo motor is currently the least powerful member of the EA824 engine family that's also installed in the 500hp Bentley GT V8, 520hp Audi S8 and 560hp RS6 Avant.
With this in mind, German tuner Abt Sportsline set out to produce the AS6-R - a car that could bridge the gap between the S6 and RS6 Avant, even exceeding the output of the latter. And since the RS6 is only available in Europe and only as a wagon, US owners of the S6 sedan can get closer to experiencing what the factory hot rod feels like for less money.
Abt claims the EA824 motor has plenty of headroom, demonstrating its 700hp version of the RS6 motor on the dyno during our visit. So taking the AS6-R conversion to 600hp and 553 lb-ft is well within what the tuner regards as "sensible" limits.
The increase was found with a pair of larger turbochargers and software tuning. The Abt engineers claimed the turbos were "modified" and we suspect they may be based on the RS6 units, since the stock S6 turbos couldn't flow enough air. The corresponding software ensured sufficient fuel supply and, while it could have been based on RS6 maps, there are many differences between the two applications that would have required custom tuning.
We should put the AS6-R into context since the increased output represents one of the biggest jumps in Abt's tuning history. In fact, its extra 180hp and 148 lb-ft equates to 42.9 and 36.4%, respectively.
Perhaps inevitably, the power and torque curves are slightly different from stock. So where the S6 makes its 420hp available from 5500-6400rpm, the Abt turbos and software develop the full 600hp at 6000rpm. Similarly, the stock 406 lb-ft is delivered across an impressive plateau from 1400-5200rpm, while the AS6-R brings its 553 lb-ft from 2900-5200rpm. In reality, the peakier torque number is irrelevant since the tuned motor is making more twisting force at 1400rpm than stock, so it's stronger throughout the rev range, although its peak numbers are delivered slightly higher.
Another interesting statistic is that the AS6-R produced the same 226g/km of CO2 emissions as the stock Audi S6. This is partly the result of the EU emissions test cycle being carried out at part throttle, but it gives you an idea of the engine's efficiency.
Thanks to the quattro all-wheel-drive system, there's no problem deploying the enhanced output. In fact, the stopwatch recorded 3.9sec for the 0-62mph sprint, which is a 0.8sec improvement over the stock S6. Furthermore, 0-124mph takes 12.9sec and, with the 155mph speed limiter removed in the AS6-R remap, Vmax is now an impressive 192.6mph!
The new rear valance in the stock bumper has cut-outs for a quartet of 3.5" tailpipes that trim the stainless steel exhaust muffler. It offers a deeper, fruitier note when you rev the bent-crank V8 and only hints at the car's complete change of character. With 40hp and 37 lb-ft more than an RS6, the Abt AS6-R is a rocketship, hurling you down the road with g-force in the lower gears pinning you back into the comfortable factory leather sports seats.
Manufactured with a high quota of aluminium, the S6 is still a large, heavy car, tipping the scales at 4398 lb. However, with the body roll reduced by selecting Dynamic Mode, the car feels surprisingly agile in the bends. There are several factors for this, including Audi repositioning the engine and transmission 2.8" further back in the chassis compared to the previous model. This has helped the balance, along with the 40/60% rearward power bias. Beyond that, the optional Audi Sport Differential and torque vectoring function fitted to the car further improved chassis response and handling. In fact, the limit of mechanical grip was far beyond what was sensible to explore on public roads.
So on fast country roads, the AS6-R will really compress the straights between the bends, meaning you need to lean on the brakes pretty hard. Fortunately, Abt had specified the factory ceramic brakes option as part of the AS6-R package, providing impressive staying power when repeatedly used hard.
Because of its refinement, the AS6-R is totally at home on the autobahn, where its long legs make it a consummate cruiser with comfort levels no different from stock. But pity the junior league supercar that tries to tangle with you, as that huge slug of torque will put significant fresh air between the tail of the Abt Audi and its challenger, allowing you to explore the upper reaches of its speed range.
So unlike many tuner packages, the Abt AS6-R doesn't have the tuner's aftermarket brakes or suspension. However, it does have the company's latest DR wheels that measure 21x9" all round with 265/30 Continental rubber.
The big wheels complement the fairly subtle carbon fiber cosmetic additions, which include frames around the front bumper intakes, trim pieces on the factory side skirts, mirror caps and a large rooftop spoiler. The Abt rear valance and vents in the front fenders are manufactured from injection-molded plastic.
The Abt AS6-R is an interesting package because it manages to eclipse the factory RS6 in terms of horsepower using software and turbo upgrades. Sold as a complete car in Europe, we were able to confirm with Abt America that US customers can add any of these components to an existing Audi S6. So contact them via abtamerica.com if you want to humble some sports car owners.
2014 Audi AS6 - Abt Sportsline AS6-R
4.0-liter V8 biturbo with Abt Sportsline replacement turbos, software, stainless steel rear muffler
Seven-speed, dual-clutch S tronic transmission, Audi Sport differential, quattro AWD
Stock carbon-ceramic rotors
Stock Audi Adaptive air suspension
Wheels & Tires
21x9" ET30 Abt DR wheels, 265/30 ZR21 Continental ContiSportContact 5 tires
Carbon fiber front intake frames, mirror caps, side sill covers, roof spoiler, plastic rear valance and fender vents
stock, Abt mats