SP Engineering's Mazda RX-7 FD3S - Body & Soul

Fuel enrichment is handled by a Cosmo in-tank pump, -6 Earl's lines, a custom fuel rail and SX regulator. The staged fuel injection set-up consists of 850cc primaries backed by two 720cc secondaries, all controlled by a HKS AIC. The stock ECU is still the main engine management component, but it has been ROM-tuned by SP Engineering for maximum efficiency. On the spark side, an HKS Twin Power amplifier boosts current to a set of NGK plugs by way of Ultra wires. SP's Jason Reinholdt grafted the fuel and ignition components into place.

Power meets pavement through the stock Mazda gearbox, an O.S. Giken clutch and flywheel combination, a carbon fiber driveshaft and a trick Japan-spec R.E. Amemiya rear-end with a 3.73:1 gear ratio. G-forces are subdued by a Tein coil-over system. Tein Circuit Master RA Type suspension system. The Tein system consists of four shocks, four main springs, four helper springs, spacer spring seats, thrust washers, bumper cushions, dust boots, upper pillow ball mounts, height measuring gauge and damping adjustment tool. The dampers are aluminum bodied mono-tube designs that utilize large diameter piston rods and big piston valves and feature 16 points of adjustment. Racing Beat bars add further stabilization to the suspension, which sees a good deal of g-load when the proper conditions present themselves. Brembo four-piston calipers put the bite on big drilled rotors, enhancing Chu's confidence when heading into a hairy apex or panic stopping in traffic. With the labor-intensive body tuning performed on the Mazda, upgraded brakes are excellent insurance policies.

Chu's RX-7 will be tuned as a driver delivering its power at a conservative 19-psi. Since Chu was out of the country when this article went together and the Mazda's registration lapsed in the interim, the engine could not be properly broken in. As a result we have no dyno charts to illustrate the the car's bottom-line power. If things line up properly we hope to bring you the tuning portion of the story at turbomagazine.com.

The orange hue of this Mazda is loud, so is its 13B at full song, but the RX-7 really screams of craftsmanship and, like our duo of old schoolers on last month's cover, this rotary flexes upper echelon craftsmanship in spades.