Lessons Learned In Championship PRO Rally Effort Applied To The Street BY MITCH McCULLOUGH Drilled pedals, including a massive dead pedal, are identical to those on the rally car. The 16x7.5 inch TSW Hockenheim wheels with 205/45 VR16 Yokohama AVS Intermediate tires fill the fender wells. The Road/Race Mazda 323 GTX for the street is happiest on pavement, but can quickly be set up for unpaved roads. Mitch McCullough's Mazda 323 GTX rally car won the 1993 California Rally series and 1994 SCCA Southern Pacific Divisional PRO Rally championships. When Mazda introduced the 1988 323 GTX as a "street legal rally car," it backed its claim with a turbocharged engine, four wheel drive and a factory-supported rally effort. The GTX was a blast to drive, but the American masses had difficulty understanding the benefits of high-performance four-wheel-drive and even more difficulty justifying prices ranging from $12,999 to $15,999. After all, the GTX looked like the 323 commuter car next door. As a result, Mazda Motor of America dropped the GTX after only one model year and may have sold fewer than a thousand examples. In the ensuing years, the GTX was sought after by rallyists and became a cult car for enthusiasts. Today, it's still a fast, fun, reliable street car and a great divisional-level PRO Rally car--if you can find one. We found two. Each had an odometer around six figures. One became a championship-winning rally car, the other a fast, semi-invisible, road warrior. A stock 323 GTX is equipped with a 132-horsepower, 1.6 liter DOHC turbocharged engine, four-wheel disc brakes and a floor pan that's 20 percent stiffer than the plain vanilla 323. This package is suspended by MacPherson struts in front and Mazda's Twin Trapezoidal Link setup in back, with front and rear stabilizer bars. The four-wheel-drive system uses a center differential with a lightweight planetary gear that splits torque 50:50 between the front and rear axles. The GTX handles well, particularly on loose surfaces, and boasts brisk acceleration. It offers great seats, a tremendous amount of headroom and the rear hatch can swallow a spare set of tires and all the associated gear for a weekend of autocrossing. One of its strongest suits is its predictability at the limit-the GTX never surprises the driver. But of course, we're never satisfied and sought to tune our 323 for spirited driving on mountain roads. We wanted to reduce understeer by increasing grip, reduce body roll for improved transient response, and boost power and torque. Our 90,000-mile Mazda 323 GTX rally car helped us win the 1993 California Rally Series championship, the 1994 SCCA Southern Pacific Divisional PRO Rally Championship, and the 1993 CRS Rookie of the Year driver and co-driver titles. So we figured we would apply what we learned preparing the rally car to a street application. We chose a 323 GTX because of the economies of scale and parts interchangeability of driving the same type car we race. However, we could have selected any number of platforms for this project. We wanted a chase car that would handle well and survive hard driving on less-than-ideal roads, yet would be fun and practical for everyday driving. We wanted it to be capable of competing in an autocross with the potential to become a rally car - in case I wrote off the race car. I asked Road/Race Autosport in Los Alamitos, California, to do the work. Road/Race had prepared and maintained the rally car. Scott Webb, a road racing champion and the former marketing director for HKS USA, and Mike Welch, an expert at fabrication and race preparation, founded Road/Race last year. The company specializes in preparing imported cars, mostly Japanese, for street and race applications and has become one of the fastest growing shops of its type in Southern California. We located a GTX with more than 120,000 miles on the clock, but it had not been crashed or modified. Hood vents reduce temperatures under hood by allowing hot air to exit. Lower stress bar increases rigidity by tying lower control arm pivot points. Front strut bar increases body rigidity, eliminates tendency of strut towers to rotate inward and gravitate toward center of car. Parking lot dings were repaired and the upper two thirds of the body was repainted black, easier and less expensive than painting it the original metallic charcoal. Road/Race Autosport installed a pair of hood ducts developed for rallying that reduced engine temperatures by allowing hot air to exit. Our objectives with the suspension were in conflict: We wanted a relatively low street/autocross setup that could later be raised for rallying. So Road/Race designed a strut suspension employing adjustable spring perches, Tokico gas strut cartridges and Eibach springs. This system provided a dramatic improvement, reducing body roll significantly. While the worn stock suspension was bottoming in dips, the new suspension provided excellent resistance to compression - in spite of a reduction in ride height of more than two inches. The biggest gain, however, was in transient response. With its sacked suspension, the old GTX was a chore to drive. The improved damping of the Tokicos and higher spring rates of the Eibachs transformed the 323 into a race car with superb transient response. The anti-roll bars were left alone; too much roll stiffness would only result in lifting wheels in tight, bumpy corners. The adjustable perches provide quick adjustment of ride height, allowing us to easily raise or lower the car nearly four inches. We can alter the ride height when switching between street, autocross and off road (snow and gravel) setups. If we need to prepare the car for rallying, we can install a set of rally springs and adjust the height accordingly. If adjusting ride heights is not important and your car is more mainstream than our GTX, then you'd probably do better with a standard Tokico strut assembly. To increase structural rigidity, Road/Race installed front and rear strut bars that tie the tops of the strut towers together, along with a front lower stress bar attached to the lower control arm pivot points. The front strut bar and lower stress bar reduce chassis flex and eliminate the tendency of the strut towers to twist and fold inward-a real problem on the rally car. Road/Race developed the rear strut tower bar, called a Solo Bar, to perform the same duty on the street car performed by the roll cage on the rally car. Road/Race designed its Solo Bar to increase chassis rigidity and to serve as a mounting point for a competition safety harness. We chose Yokohama 205/45-VR16 AVS Intermediate tires mounted on TSW Hockenheim 16x7.5 inch alloy wheels to complete the handling package. We were impressed with the racing heritage of TSW and liked the rally/European Touring Car look the 16 inch wheels gave the car. The Yokohama AVSs offered the balance of high performance and wet weather capability we were seeking. To boost power output, we freshened the engine and installed an HKS manual boost control and HKS PFC F-CON fuel controller. We added an HKS muffler and a Megs exhaust tip that resulted in a pleasing exhaust note without violating emissions requirements. As in the rally car, we employed 20W50 Torco synthetic racing oil in the engine and Torco synthetic gear oil in the gearbox. The weak link in the 323 GTX drive train is the gearbox. To further protect this link and increase performance, we installed a Centerforce dual-friction racing clutch assembly. This equipment lowered our 20-60 mph times by a full second. We were more interested in getting around slow moving vehicles on mountain roads, than standing-start performance. To protect our investment, Road/Race installed an attractive Sigtronics digital exhaust gas temperature gauge that is inexpensive, but provides precise readings of combustion temperatures. We also installed a VDO turbo boost gauge to replace the inadequate stock readout. A GReddy turbo timer was installed, which we found handsome, easy to use and relatively inexpensive. Tokico gas strut cartridges and Eibach springs work well with Road/Race's adjustable perches. Note the braided steel brake lines. Inside, we fitted a Momo Benetton Evolution 2 steering wheel, a Momo Competition shift knob and a set of Road/Race aluminum drilled pedals with a massive dead pedal-all identical to the components used in the rally car. We installed a set of Schroth Autocontrol Harnessbelts that provide increased safety and driver control, yet are comfortable and easy to use. The Schroth (pronounced Shrote) belts are the only belts on the market approved by the DOT. With the work we put into it, our 323 GTX was still an inexpensive car, yet offers phenomenal performance, is fun to drive and attracts compliments regularly. All it needs now is a big set of rally lights and some mud flaps.