Some engine and exhaust combos sound better than others. For many, the wide-open scream of the NSX's C30A V-6 at 9K rpm is heaven. For others, a Nissan V-8's instant crack from idle raises the neck hairs. But the distinctive sound from the turbocharged 1.3-liter rotary engine and proprietary exhaust system in this Knight Sports Mazda RX-8 can't help appealing to everyone.
It's almost like a siren as the revs build up, announcing that something earth-shaking is about to happen. After reading this, go to YouTube and search "Knight Sports RX-8 / Power Run", and fast-forward to about 0:55 to understand what we're talking about.
Knight Sports is a Tokyo-based company that specializes in rotary engines and has been in business for more than 30 years. Our contact for this car, chassis code SEP3, is Hidefumi Nakamura. Now 57, he's had the motorsport bug since high school, when he went to see a race at Fuji Speedway. Since then, he has peered into the deepest nooks and crannies of rotary engines, and his cars have occasionally kicked the butts of Japan's fastest. So when he advises people who are thinking of undertaking a similar project to "take it one step at a time," it would be a smart thing to listen.
This RX-8 is an out-and-out track car, built in gradual phases and tested on the circuit to be sure that each addition, subtraction, or tweak can make the car go faster for longer. Knight Sports makes a lot of its own stuff, including the body kit. This takes in a Type II front bumper and lip, side skirts, and a rear bumper/valance. A custom-made hood has been designed to help bring cooling air into the engine bay while a KS GT-style rear wing helps outside air create downforce.
Going from outside to in, there isn't much left of the standard car-a bit of dash and steering column, and that's about it. Instead, there's a custom-made roll cage, pimp Defi Super Sports Cluster, an NGK air/fuel and boost meter, and an HKS EVC-5 (electronic valve controller) boost manager. The driver sits in a Knight Sports bucket seat and twirls a Nardi Torino steering wheel.
Then he will mash the throttle and bring the big guns to the party. In this case, a 13B-REW twin-rotor, fitted with a Turbonetics 60-1 trim/0.84 A/R turbocharger. This is connected to a Knight Sports manifold, while an HKS blow-off valve and GT-II wastegate perform their duties. Nakamura also had the housings ported and changed the lubrication to a race-standard dry sump system. An A'pexi Power FC stand-alone engine management system talks to NGK Racing 11.5 spark plugs via an Accel 300+ digital ignition unit. These guys set fire to gasoline supplied by 550cc/min primary injectors and 850cc/min secondaries, regulated by an HKS pressure regulator, and fed by a pair of Bosch pumps via an Arias fuel rail.
Making sure the Fahrenheit is on the money and not about to cost money (a job that's even trickier with a rotary) is an intercooler and piping made in house, accompanied by an all-aluminum radiator-with both arranged in a V-mount setup (that vented hood was a giveaway, wasn't it?). And let us all give thanks for the Samco Sport hoses and Setrab oil cooler. Amen.
That siren sound is the accompaniment to the engine making 440 hp with boost levels at 14.7 psi (1.0 bar). Up that figure to 17.4 (1.2 bar) and there's 480 hp to play with. Or 500 hp with 18.6 psi (1.3 bar) of boost. All this from a displacement of 1.3 liters . . . isn't technology wonderful?