The second-generation Mazda RX-7 is a typical creation of the 80s car industry - a "clean" body design, a spartan interior, a light car weight and a fun high-revving rotary engine. Mazda's development team, led by chief project engineer Akio Uchiyama, focused on the US market, where most of the first-generation RX-7 models were sold, when developing this RX-7. The designers took inspiration from the highly successful sports cars that were extremely popular in the American markets at the time. One such was the futuristic Porsche 928 car introduced in the 70s, from which the RX-7 "inherited" both the excellent body design and the independent rear suspension. The other was a slightly newer and cheaper Porsche 944 model, which can be called a direct competitor to the Mazda RX-7, or the even cheaper Porsche 928, whose interior can be said to have been simply copied by Mazda engineers. With the second-generation RX-7, Mazda introduced the Dynamic Suspension System (DTSS). This suspension was notable for having special suspension control hubs that allowed for passive rear wheel steering under cornering loads greater than 0.5g. In this way, the behavior of the car in turns was better controlled. Another new feature at the time was the Adjustable Suspension System (AAS), which could adjust the suspension's damping characteristics depending on road conditions. The Mazda RX-7 "Series 4" was produced from 1986 to 1988 and had a naturally aspirated 13B-VDEI engine that produced 146 hp (109 kW). The more powerful version, the Turbo II, had a turbocharger and developed a rather solid 182 hp (136 kW) of power and 248 Nm of torque at 3,500 rpm. The updated 5 Series was produced from 1989 to 1992 and featured an updated body design, improved engine management, as well as lighter rotors and a higher compression ratio. The naturally aspirated 13B-DEI now produced 160 hp (119 kW), while the turbocharged version produced all 200 hp (149 kW) and 264 Nm of torque at 6,500 rpm.