Take a garden-variety 924/931, strengthen the suspension setup, widen the footprint, ensure it remains cool, and go racing. That's a formula that's worked with many racers, but some have higher standards. After Britain Smith and Dr. Gary Chapman had a bit of a rocky start with their 931, they decided that they would give their car the additional power and reliability necessary to make it a regular contender.
Fortunately, in the welcoming world of Lucky Dog Racing League, the relaxed rules make it possible to exchange the original four-cylinder for something a little wilder, so quickly Smith and the team's dedicated mechanic Tom Claussen began laying the groundwork for a serious engine swap. The chosen platform: an AAN five-cylinder from a '93 UrS4 fed by a VF-39 turbocharger. It's not as monumental a task as it might seem since the AAN bolts up to the 931's G31 gearbox.
Of course, there were some fitment issues. After relocating the throttle body to clear the master cylinder, a new oil pan to clear the crossmember, the motor was mostly installed. Then came a little tubing to strengthen the front after a crash and a set of Ground Control front struts, and this was was the spectacular result:
Overall, the AAN has been both powerful and reliable enough to win two consecutive titles in Lucky Dog, but it has some weak points. Its gearbox is a little on the fragile side, and sometimes keeping the motor on boost is a challenge at the tighter circuits it frequents in the Pacific Northwest. Kirk Myhre, the only guest driver not to have broken a gearbox, elaborates on what it takes to get a quick lap out of this little monster:
"It has good power, but you have to be in boost. Keeping it there is a challenge at places like Oregon Raceway Park and The Ridge—especially when following traffic. Also, the turbo is pretty linear but it can surprise you if you’re accelerating hard out of a corner, like when leaving Turn 3 at Portland International Raceway."
Once one can drive around those shortcomings and retrain their brain to work with a dog-leg five-speed, the car is quite agreeable. "You stand it on its nose under hard braking and the rear comes around progressively and accepts throttle while it's still rotating," Myhre adds. It's a friendly platform with a distinctive bark and enough power to hang with the V8 competition. Plus, it has those classic proportions that, complete with a Sunoco-inspired livery, look absolutely stunning. What's not to like?