Turbo Magazine Article

Last updated: April 3, 2001

Tube-Frame Chronicles: RX-7

Three Rotors, One Bottle, Big PowerA Puerto Rico-based Mazda RX-7.

Robert Choo
Photography by Gary Castillo

Courtesy of Turbo Mag logo

Rivera car photo When conjuring up images of tube-framed import racers, one particular country dominates the cerebral cortex--Puerto Rico. With a total population of just under 4 million, the country unofficially produces more tube-framed racers per capita than any other country in the world. Racing to Puerto Ricans is as much a necessity as water. When you consider the two tracks on the island are open four days a week, racing has become a lifestyle. Anibal Rivera of Nibo Racing exemplifies this lifestyle with his impressive tube-frame 1994 Mazda RX-7.

Rivera's RX-7 started with nothing more than a bunch of chrome-moly tubing until legendary chassis builder Kike Sheilds (pronounced "Kee Kay") fired up his welder. Kike Sheilds is the Michael Jordan of chassis builders in Puerto Rico. The Nibo Racing chassis utilizes a four-link Ford 9-inch rear-end with Afco double adjustable shocks and springs at the four corners. Just in case the parachute doesn't blossom properly at 170 mph, Aerospace calipers up front and Strange units out back are sure to bring the car to a complete halt in ample time. Aerolite aluminum wrapped with Goodyear rubbers reside under the wheelwells.

Rivera car photo Propelling the vehicle into the 7-second club is a turbocharged rotary powerplant. Puerto Ricans love the rotary engine, to say the least. You can find a rotary in almost every possible racer; be it a Datsun, Nissan, Toyota, Mitsubishi or even a Honda, don't be surprised to find a rotary engine in it. Rafael Padilla massaged the 13B powerplant to handle the abuse of force-feeding. He fortified the engine with stronger apex seals from Francesco Iannetti, known as the Giorgio Armani of apex seals. Considering the plan called for injesting 30-plus psi of boost pressure, it better have the best of the best. Padilla also ported the rotary housings to increase airflow before balancing and blueprinting the entire powerplant. Sheilds was also responsible for building the turbo manifold. Although the turbo specifications were kept secret (for obvious reasons), from the pictures, we can tell that the hairdryer is a T4 unit. The T4 turbo has been tuned to an astronomical 38 psi of boost pressure, but at the car's coming out party, it was only running 33 psi. On the intake side the rotary runs a Sakura Motorsports throttle body with a Jaytech intake manifold.

Rivera car photoGet this, a total of eight 1,600cc Kinsler squirters are required to meet the Wankel's insatiable appetite for alcohol. Twin Weldon fuel pumps supply the alcohol to a pair of Kike Chassis Shop fuel rails. The fuel system is regulated by a single Kinsler regulator. Igniting the compressed fuel are dual MSD 7AL-2 boxes with two MSD Pro coils. The amped charge is sent through Moroso plug wires, zapping NGK spark plugs. Engine management chores are handled by a top-of-the-line Haltech F9-8 fuel computer. The owner claims that this potent combination is capable of producing 700 hp at 38 psi of boost pressure.

The rotary engine's kinetic energy is transferred to a McLeod flywheel and clutch. A G-Force air shifted five-speed transmission delivers the power to a Mark Williams driveshaft and Mark Williams axles. Extra-wide Goodyear 31-inch gumballs launch the RX-7 to blistering 1.16-second 60-foots and 7.92-second quarters.

Rivera car photoThe RX-7 has already surpassed Rivera's expectations as the Mazda was built originally with low 8-second runs as the target. Amazingly enough, the Mazda blistered a best of 7.92-seconds at its very first outing. With only four passes under its belt, the "7" is sure to go quicker with more runs. Rivera also plans to turn up the boost after he finishes dialing in the chassis, so watch out. The Nibo Racing "7" is out to give some contenders a beating at the next event. Who knows? Maybe Rivera might become the next world's fastest door slammer. One thing is certain, back home in Puerto Rico, he will be busy four days a week.

Rivera car photo

Courtesy of Turbo Mag logo

[Mail me] [To Lightning home] [To my home page] [Copyright Notice]