When Audi introduced the B6 S4 back in 2004, its move to a V8 seemed like the best strategy for taking on its top rival the BMW M3. BMW had been fighting homologation rules, trying to race a V8 powered M3 even though they didn’t yet build such a beast while Audi actually had such a car coming into series production. Peak power for the S4 jumped to then M3 levels and the glorious song of the 4.2 V8 was a winner even if the normally aspirated engine would prove expensive to tune. Added weight in the nose despite the 4.2’s aluminum block didn’t help much either, though the 340 hp almost always on tap no matter the rev count made for a very addictive setup. Times have changed though since the B6 S4’s introduction. Fuel prices have risen and so has environmental awareness. As Audi itself moves to downsize weight, engine size and consumption companies like AWE Tuning have stepped up with their streetable power upgrade kit that will turn the frugal yet tunable A4 2.0T into an S4 by any other measure than cylinder count.
As if to emphasize the point, AWE set about building just such a car that would utilize just about every upgrade and then some that the Philadelphia-based firm had in its burgeoning B7 catalogue. And where better to start than an A4 S-line – a car complete with the desired 2.0T quattro drivetrain, 6-speed manual gearbox and all in a package that is quite close in exterior appearance of the S4.
From the outside, AWE’s B7 looks like a subtly modified S4. Ignore all of the AWE decals that give it away as their demonstrator and you **might** be fooled that it’s just a lightly modded S-car with wheels and suspension. The car is lower than an S4, but not slammed and really only to a height you might imagine is available on European models. A factory S4 rear valance with quad AWE-etched tips, 19-inch BBS RG-R wheels powder coated in black and shod with 235 35 19 Sport Maxx rubber as well as a factory Audi RS 4 grille might give you pause as tasteful add-ons, but don’t scream “LOOK AT ME!” or “Don’t bet the pink slip.”
Of course, there is that menacing intercooler and associated piping peaking out from behind the grille’s black hexagonal mesh. There are those red-painted Brembo calipers with cross-drilled rotors peering from their hiding place behind the BBS’ forged spokes. It is perhaps at this point when a closer look becomes a much higher priority.
Pop the S-line’s bonnet and you’ll see the heart of the transformation. This particular black A4 was one of the first B7s to be fitted with AWE’s GT28-71R Turbo Kit. When it comes to longitudinal 2.0T tuning, AWE bills this as their ultimate solution with a claimed streetable 377 crank hp and 317 crank lb-ft of torque.
The heart of the system is a custom GT28-71R turbo made to AWE specifications with a nickel alloy turbine housing for higher operational temperatures by Garrett. The kit also includes an A.W.E. cast stainless CF8C-Plus alloy exhaust manifold engineered for high temps, high pressure fuel pump, high pressure injectors, Nomex fiber reinforced silicone boost hoses and software with multiple programs including Pump Fuel, Valet Mode and Ignition Kill Mode from longtime development partner G.I.A.C. Unique in the segment, the kit also includes an HJS 200 cell catalytic converter assembly sourced from a German OEM supplier – important if stricter emissions are dictated by either smog-check inspection criteria or a green-tinted conscience.
Though AWE does offer a detuned version of the kit in order to run with stock intercoolers, the company also can provide one of the most impressive B7 intercooler upgrades we’ve seen and this car was a prime candidate for the fitment.
What makes the intercooler such an intriguing piece of kit? Well for one, it’s one of the largest we’ve seen that will still mount to the A4 without any cutting of the frontal crash bar or additional modifications of any sort with the exception of an AWE-supplied replacement for the power steering cooler assembly. It’s not just about size though. By using computer aided Computational Fluid Dynamics AWE was able to maximize airflow and thus increase efficiency. The end result is a maximum 27-degrees of cooling and 50% less restriction over the factory setup.
Not surprisingly given the power, a high-performance exhaust system is required with the GT28-71R kit. AWE leaves which to choose in the hands of owners, but one obvious choice is the company’s own mandrel bent T304 stainless steel 2.5” system now available with the aforementioned S4-style quad tips in limited run Diamond Black polished finish and upgraded downpipe (manual transmission only) like the setup seen on this particular ebony 4-door.
Other AWE catalogue goods under the hood include the company’s diverter valve upgrade and fuel pump upgrade featuring a special low-friction DLC coating.
Not surprisingly, the car’s suspension and brakes have been upgraded to meet the demands of its newfound performance with two of the best known names in their given segments. Bilstein PSS-10 coilovers, an AWE staple, offer fully adjustable height and dampening settings that can be performed via a knob with the suspension on the car. In the meantime, Brembo’s 328 mm brake upgrade kit that uses a caliper fitment from the Lotus Exige and bestows the car with much more stopping ability and is also compatible with the A4’s ABS system. Those red Brembo calipers look the business behind the spokes of those black finished BBS wheels as well.
Inside, changes are minimal and functional. Most obvious are a few OE+ upgrades snagged from elsewhere in the B7 range. A full set of Recaro seating in black leather from an S4 that AWE sourced from one of their auto recycler sources – a big improvement over the A4’s less bolstered thrones. At the driver’s feet are a set of AWE’s own design aluminum pedals.
An AWE center-mounted boost gauge affixed in the A4’s ventilation opening helps keep an eye on the liberal levels of boost on tap from the engine. AWE was the pioneer of vent-mounted gauges and this must certainly be one of the nicer offerings of this type in the aftermarket. Design is slightly different from the A4’s instrument cluster, but the LED lighting is spot on to match the car, making for a clean overall look that doesn’t scream aftermarket.
Slipping into the Recaros and firing up the A4, we’re greeted by a slightly louder tone than stock. The sound is somewhere between OE and aftermarket and likely “aggressive enough” for most while not being overbearing. Take your boss or mother out for lunch and they’ll notice the hooligan tone, but you won’t be setting off car alarms.
In low revs, the car feels quicker than factory but not appreciably so. However, rev on up past 3000 RPM or so and the boost comes up to boil – the A4 shoves you back into your leather Recaro. From there to indicated redline the Audi just pushes harder and harder. AWE states 340hp at the crank on 91 octane fuel as fitted with their larger intercooler and 377hp on 93 octane, which is how we tested it when we stopped in for a test drive at their corporate headquarters outside Philadelphia. You feel every bit of that extra power once you hit the sweet spot in the rev range. Pump any more out of the factory 2.0T and AWE recommends you consider beefing up components such as connecting rods. In other words, they’ve developed the system as a bolt on kit with various degrees of tune all the way up to the 2.0T’s factory tolerances.
Driving the AWE Stage III A4 while using all of its power becomes more like driving the iconic Sport quattro – more powerful than a highly tuned 1.8T though much more linear in delivery. You do need to keep revs up in order to really pile on the horsepower. Lazy around town driving at low revs will leave the car feeling more sluggish by comparison. It’s the antithesis of the big lazy 4.2 in the S4, one that challenges you to keep the tach at 12’oclock or beyond and rewards you with a dramatic shove in the back… and one that won’t hit you at the pump much harder than a stock 2.0T.
All things considered, AWE’s black B7 is every bit as fast as an S4 and likely faster. Given its dramatic delivery, it actually feels a lot faster. Even better, it’s doesn’t have all that weight in the nose to push around. Considering the 2.0T’s augmented power, the upgraded braking and suspension and the added functional and visual flare from the RS 4 grille and Recaro seats to the quad-tipped exhaust, this is very much an S4 by any measure other than cylinder count.
For more photos of this car and its many upgrades, please follow the link below to our large photo gallery.
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