|Point Eight Bar:
An Audi A4t Transformed by the Right Tweaks
By: Brendan M. Lopez
Photos by: Les Bidrawn
This article appeared in the June 1998 issue of european car magazine. Reprinted with permission.
Wearing renowned red rings and silver paint of Audi's factory-sponsored touring cars bears a certain responsibility. Upholding the motoring traditions implied by the appearance is no easy task. Dave Peterson of Sport Wheels has done it right. Though this A4 1.8t quattro borrows styling cues from Audi's factory racecars, it isn't just another lowered car plastered with decals. This A4 has the handling performance to match.
Audi's five-valve-per-cylinder 1.8 liter turbocharged engine puts out a respectable 150 hp and 155 ft-lb of torque. This enables sprints from 0 to 60 mph in a respectable 8.1 sec, yet the engine still is operating far below its potential. Unlocking more horsepower is easily accomplished by making the turbocharger pump more air into the engine. Modern electronics mean the days of replacement wastegate springs and black boxes are all but over. Now all that's required for many horsepower upgrades is some new engine management software combined with traditional breathing modifications. For software Sport Wheels chose the German firm of Wetterauer, which offers a number of different chips for the 1.8t engine. The chip in this car delivers 0.8 bar of boost and 180 dyno-tested hp (the chip was tested in a front-wheel-drive Passat that shares the same 1.8t engine).
An optional dash-mounted toggle switch enables the driver to switch between the stock chip and the Wetterauer chip. Engine breathing is further improved with a Ramair filter and custom B&B 2.5-in. cat-back stainless-steel exhaust system. The front valence features an integrated scoop to force air onto the stock intercooler.
With 180 hp at your disposal, acceleration is dramatically improved over stock. I've spent a fair amount of time in a stock A4, and the difference is felt immediately. The power comes on smoothly and builds much more quickly, and it does so without creating the sense of unleashed fury which characterizes over-boosted turbo systems. Much of the drivability can be attributed to Wetterauer working closely with Sport Wheels on the engine management system. (For those who can never get enough, Wetterauer offers a second chip which delivers a full bar of boost and puts on a purported 200 hp.)
Handling is an area where the A4 quattro excels. It is simply a fantastic car that handles phenomenally well, characterized by razor sharp lines and controlled cornering (which made the action photography difficult; it's hard to depict drama when the subject is so well behaved). With a four-link front suspension and double control arm rear suspension, the only change it truly needs is a good set of shoes. It is easy to change how a car handles, but improving a good handling car takes a bit of work. Rather than go with off-the-shelf suspension components, Sport Wheels had a set of custom Bilstein Sport shocks designed and built for this car (Bilstein doesn't offer an over-the-counter fitment for A4 quattro models).
Sport Wheels is also working with Bilstein to develop large, threaded body coilover shocks. The day after this photo shoot, Eibach was prototyping a new set of springs. Dave feels that the current 2.0-in.-lower Eibach springs are a bit too low for the driving conditions in Colorado but work beautifully on the track.
Inspired by touring cars, this A4 wears a set of 8 x 17- in. MSW/O.Z. alloy wheels shod with Pirelli p7000 performance radial tires, size 225/45-17. As a matter of convenience, Sport Wheels uses a set of studs instead of bolts to mount the wheels. Stuffed inside the front wheels is a set of AP Racing brakes featuring 330,m, diameter discs and 4-piston calipers, fed fluid via Goodridge DOT-spec stainless-steel braided lines. Dave has tried a few different brake pads up front, ultimately choosing Ferodo for all-around good performance. Even when carving canyons and making repeated hard stabs at the brakes, fade is simply nonexistent. As a bonus, the ABS system is fully operational even with the AP conversion. The only changes to the passenger compartment are related to safety. Up front a set of Sparco Supersport seats are mounted to Sparco sliding rails. These seats are a hybrid design offering street adjustability along with provisions for racing harnesses-here Schroth Rallye four-point units. The only other interior change of note is the aforementioned toggle switch on the dash for changing between engine management programs.
External changes are both subtle and striking. Subtle are the European headlamp assemblies and clear corner lights. Striking is the Eucra Racing rear wing and BRCC-style graphics. Sport Wheels designed the computer-cut vinyl graphics by using photographs and models to position the rings. The four rings of Audi are the most noticeable feature, and they also demand the substance behind the right to wear them. You have to be able to back up the look. Sport Wheels has succeeded.
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