Guest
The third generation RX-7, FD (chassis code FD3S for Japan and JM1FD for the North America), featured an updated body design. The 13B-REW was the first-ever mass-produced sequential twin-turbocharger system to be exported from Japan,[13] boosting power to 255 PS (188 kW; 252 hp) in 1993 and finally 280 PS (206 kW; 276 hp) by the time production ended in Japan in 2002. In Japan, sales were affected by this series' non-compliance with Japanese dimension regulations and Japanese buyers paid annual taxes for the car's non-compliant width. As the RX-7 was now considered an upper-level luxury sports car due to the increased width dimensions, Mazda also offered two smaller offerings, the Eunos Roadster, and the Eunos Presso hatchback. The sequential twin turbocharging system, introduced in 1992, was extremely complex and was developed with the aid of Hitachi. It was previously used on the exclusive-to-Japan Cosmo JC Series. The system used two turbochargers, one to provide 10 psi (1 bar) of boost from 1,800 rpm. The second turbocharger activated in the upper half of the rpm range, during full throttle acceleration — at 4,000 rpm to maintain 10 psi (1 bar) until redline.[14] The changeover process occurred at 4,500 rpm, with a momentary dip in pressure to 8 psi (1 bar),[15] text=and provided semi-linear acceleration and a wide torque curve the throughout the entire rev range under normal operation. Under high speed driving conditions, the changeover process produced a significant increase in power output and forced technical drivers to adjust their driving style to anticipate and mitigate any over-steer during cornering.[citation needed] The standard turbo control system used 4 control solenoids, 4 actuators, both a vacuum and pressure chamber, and several feet of preformed vacuum/pressure hoses, all of which were prone to failure in part due to complexity and the inherent high temperatures of the rotary engine.[15]
