1993 Mazda RX-7

The third generation RX-7 features a body design that was unusually sensuous for a relatively affordable sports car. Mazda broke all the rules with this design. One of the rules was a Japanese law that dictated the width of the car. As a result, buyers had to pay a special annual tax for being out of compliance.

The RX-7 used a sequential twin turbocharging system that was extremely complex and was developed with the aid of Hitachi. The system uses two turbochargers, one to provide 10 psi (1 bar) of boost from 1,800 rpm. The second turbocharger activated in the upper half o the rpm range, during full throttle acceleration - at 4,000 rpm, to maintain 10 psi (1 bar) until redline. The changeover process occurred at 4,500 rpm, with a momentary dip in pressure to 8 psi (1 bar).