G/GCC- and G/FCC-class regulations forbid forced induction, and Doug knew that the easiest way for the hungry K20A to breathe on its own would be through a set of individual throttle bodies. "Kinsler and I tested dozens of combinations of varying width, length and shape runners and inlet set-ups before deciding on what you see here, and a lot of the data went into the revision and development of off-the-shelf kits." To make the most of them, Doug's RSX spins IPS S2 cams for naturally aspirated duty, and fuel is provided via four 1,200cc RC injectors, managed with a Hondata K-Pro to produce 284.9 whp and 182.2 lb-ft of torque.

In the "fuel" classes, where the use of an oxidizer is permitted, Doug uses a custom Edelbrock direct-port dry system that delivers two 70hp shots that produce a total of 415.7 whp and 274.4 lb-ft of torque. "We found that we could effectively increase power by a factor of about 50 percent before reliability becomes a concern," he explains.

Not much changes with the engine for blown-class prep. Two Kraftwerks Rotrex superchargers--a C30 and a C38--are fitted to the engine, and plumbed into a liquid-to-air intercooler. Injectors are swapped out for 1,600cc RCs, the IPS cams are yanked in favor of a stock '06 TSX intake cam and an '04 RSX-S exhaust cam, and the engine is re-tuned to make 684.7 whp and 390 lb-ft of torque. "The linear power production and instant throttle response of supercharging is very advantageous to top speed racing," explains Doug, "And we found that two smaller chargers offer the ability to spin faster than one large one,"--an important point to mind when your engine spends about a minute and a half of each run producing between 600 and 680 whp at a constant 8,500 and 9,500 rpm. Adding a small shot of nitrous to this set-up produced just over 765 whp once, "But that was just for fun," Doug advises.