Pedzisa mutsara unotevera: Muna 1979, kufambira mberi kukuru kwakaitwa muaerodynamics uye kupikisa Lotus, Forghieri akaziva kuti aifanira kutevera kutungamira kwavo uye kugadzira motokari yevhu ye1979. 312T4, yakatangwa pa
1979 South African Grand Prix yakanga yakanyatsotarisana ne312T3. Mavambo ayo akaisa zvinorambidza pane aerodynamic dhizaini sezvo iyo T dzakateedzana yakanga isina kumbobvira yakagadzirirwa nepfungwa yepasi. The 312T4 monocoque rakagadzirirwa kuva sezvo yakamanikana sezvinobvira, kushandisa migumisiro pasi, asi ichi chakanga chakaganhurirwa upamhi flat 12 injini.