Bill Auberlen is a veteran, one of the most successful BMW drivers in the world. His career highlights include a fourth- and fifth-place finish at the 1997 and 1998 24 Hours of Le Mans in a McLaren BMW and BMW V12 LM, and the Sports Car GT-3 Championship title in 1997 in a PTG E36 M3. This year Auberlen is at the front of the Speed World Challenge GT class in an E46 M3 prepared by PTG Racing--a team which is leading the field with all four of its M3s in the top six--and also the Touring Class in the #93 Turner Motorsport BMW 325i. When Editor Brown told me I was going to strap into Auberlen's race seat and drive the Streets of Willow Springs in Rosamond, Calif., I almost needed a five-point harness to hold me in my desk chair.
The SCCA Pro Racing Speed World Challenge is a series divided into two classes, Grand Touring (GT) and Touring Car, the cars are grouped based on their performance potential and market segments. Only normal production vehicles available to the general public, manufactured from 1997 to 2003, are eligible. Vehicle weights and wheel/tire sizes are governed to achieve equality in performance. Modification companies and small-volume manufacturers may also be accepted on a case-by-case basis, and all vehicles must be accepted by SCCA Pro Racing.
If you've ever wanted to see how a BMW M3, Audi RS6, Porsche 996, Viper GTS or a Corvette Z06 fare against each other, the GT series is the one for you to watch. The Touring Car class is just as, if not even more, exciting. With nearly 70 cars on this year's roster, an intense combination of BMW 325s, Acura RSXs and Integras, Mazda Proteges, Lexus IS300s, Audi A4s, Nissan SE-Rs, Subaru Imprezas and Honda Civics keeps spectators on their feet. The GT cars run on Toyo RA-1 R-compound tires, but the Touring class is required to run shaved Toyo Proxes T1-S street tires. Although the majority of cars in the Touring class are Japanese, BMW 3 Series are consistent front-runners.
Turner Motorsport is a leading BMW aftermarket company and has been involved in World Challenge racing continuously since 1998--longer than any other team except Real Time Racing--and Will Turner has racked up more than 50 starts. Two wins in 1999, breaking an eight-race Integra Type-R streak, helped Will to a fourth in the championship. In 2002, Will led the most laps and the most miles and had the most fastest laps, but three DNFs held his season-end standing to sixth place. Extensive off-season testing and recruitment of Bill Auberlen helped set the tone for 2003 with a season-opening win at Sebring. As this is written, Auberlen has 181 points to three-time champion Pierre Kleinubing's second-ranked 121. Will Turner is tied for fourth and Frank Selldorff is 24th.
The Touring Car class may look like a series for the budget-minded, aspiring racer. Don't let the near-stock-looking cars fool you--the cost to build them is calculated in units of $1,000. The TMS cars started life as a $30,000 body shell with a built-in rollcage; it then took nearly $20,000 more for the factory parts to complete each car.
On the aftermarket side, TMS had to reach even deeper into its pockets. The $24,000 engines are still the all-aluminum, 2.5-liter inline six, but they have been massaged, including 11.0:1 compression, to produce 270 bhp at 7200 rpm and 175 lb-ft at 5550 rpm on street-legal Sunoco 104 octane unleaded, the spec fuel for the class. Exhaust exits through a $7,000 TMS header and exhaust system. The engines are controlled by $8,000 MOTEC M800 engine management.
A BMW five-speed transmission with TMS short shifter and a 3.73 or 3.91 limited-slip differential (depending on the track) get the power to three-piece, magnesium BBS wheels rolling on 225/45-17 tires. TMS carbon-fiber splitters and rear wings add downforce for high-speed cornering and braking.
The TMS 325i is equipped with a full AP Racing braking system, consisting of 12.5-in. front and 11-in. rear rotors, four-piston calipers in the front and two-piston in the rear, and a pedal assembly with dual master cylinders and an adjustable balance bar--figure in another seven grand.
A $9,500 TMS/Moton suspension maximizes the car's balance and grip. TMS uses H&R springs for its race cars as well as selling them. Will related that years ago, with another manufacturer, the spring rates could vary from their nominal spec by 10% and sometimes sagged with use. TMS had to check every spring before it went in the car, as four springs varying by 5% could result in a car that was "a handful," and the team wouldn't know where to start sorting it out. Will said that the H&R springs are checked from time to time and are always right on the money. They are what they say they are and remain that way.
TMS has its suspension developed to use the smallest spring possible. It knows how much travel is required and uses all the spring at each track. There is no "extra" spring, so there is no excess weight. The other part of the equation is Moton dampers, which are three-way adjustable with a remote reservoir.
The MOTEC data acquisition system replaces factory instrumentation, telling the driver everything he needs to know about the car. A digital tach is matched with all important temperatures and pressures. It's more than an expensive instrument console, though. Everything is recorded for study after practice, qualifying and the race: steering input, brake pressure, wheel speed, suspension travel, etc. Lap times, braking points, cornering and straight-line speeds, g loads, shift points and even suspension tuning are analyzed by TMS' full-time race engineer.
Vehicle development has improved so much that Turner's times are now 3 sec. per lap faster at Mid-Ohio than when he ran there on race tires in 2000. Will said the Toyo T1-S is an impressive tire. It has its peak, then falls off to a consistent and useful level. The first or second lap is always fastest, but the third lap and the 20th lap are the same. If it is treated right, it will last the race.
At only 2,700 lb with driver (the SCCA adds weight to cars that win, so it actually races at 2,800 lb), and a perfect 50/50 weight distribution, the TMS 325i is a phenomenal race car. Before I buckled in, crew chief Marc Feinstein warned me the brakes would feel a "little bit different," and they may require a "little more pedal effort." Driving at possibly 5/10s of my capabilities in the opening few laps--yes, at crawling speeds--I couldn't even get the car slowed down for turn 1. It was soon obvious the tires were not going to lock up easily, so I started to really get on the brake pedal hard. I had never felt a stiffer pedal in my life. But even on street tires, this car stops! Thanks to OMP seat and harnesses strapping me in so that I could barely breathe, not having to fight my own body movement helped keep braking totally controllable.
With the Knight Rider-style OMP steering wheel, shuffle steering was ruled out, but the car's turn-in response was so crisp and controlled it didn't matter. With the 2.0-turn lock-to-lock steering, I had to keep reminding myself that fenders and quarter panels covered these wheels. The open-wheel/go-kart-like steering made driving this car truly pleasurable.
The Moton/H&R-suspended TMS 325i's handling is very subtle. The balance is so neutral that it can go from a mild understeer to a mild throttle oversteer within an instant. The car carved through the road course turns with such grip I couldn't believe it was stuck to the ground by street Toyos. I was amazed, yet in my heart I knew I wasn't near the car's on-track handling limits.
The power delivery is amazing. On track, there were several turns I could take in either of two gears because torque was so abundant. For sake of chief mechanic Feinstein's approaching ulcer, I opted for the higher gears to keep the revs down, and the car seemed to pull out of low-speed turns nearly as well. The times I did hold down the go-fast pedal it pulled to its 7000-plus redline with a loud, cabin-shaking roar. It amazed me that a car could have such good low- and high-end torque simultaneously with only 2.5 liters of displacement.
The abundance of torque throughout the rev band brought out a whole new perspective--the finesse required to finish the race on just one set of tires escaped me. It didn't matter what turn I was going through, what gear I was in, nor what rpm the motor was spinning--if I got on the throttle too hard exiting a turn, the car inevitably got sideways. That said, trail-braking was also a "touchy" subject. Their drivers push these cars and each other hard on the racetrack. But doing it in such a way that these tires cross the checkered flag in one piece can only be done by a true professional.
The magnitude of the competition is reflected in the dollar figure required to create a competitive car. Just the drivetrains now cost more than TMS' entire World Challenge cars did in the E36 era. TMS produces these racers at $120- to $150,000 each--I was glad to learn that after my track time. The cost to run each car in the Speed World Challenge Touring Class makes it a serious business, with serious drivers and even more serious teams. This year, Turner Motorsport separated its racing from its parts business, which ships more than 100 packages each day, so the store doesn't have to shut down to go racing. Turner Motorsport and Bill Auberlen are dead serious about doing whatever it takes to maintain the points lead and eventually clinch this year's Speed World Challenge Touring Car driver championship. So far, this TMS BMW 325i is racing down the right path.