ST165 Info

For the Japanese market, Toyota introduced the "ultimate Celica": the GT-Four (ST165) in October 1986. With full-time all wheel drive, including an electronically controlled central locking differential, and a turbocharged version of the GT-S 2.0 L engine producing 190 hp (142 kW) (3S-GTE), it immediately took its place as the flagship of the Celica range, and became the official Toyota rally car for all years of production. The GT-Four, with a revised viscous coupling central locking differential, began exporting for the 1988 model year and marketed in North America as the All-trac Turbo which was also rated at 190 bhp and 190 lb-ft torque. The All-trac system also was offered for a limited time on the Camry, Previa, and Corolla in North America sans turbo.

The ST165 chassis design was already quite acclaimed in its time. http://autospeed.com/cms/A_1820/article.html Toyota chose not to make any drastic suspension changes for the AWD GT4; The front suspension comprises MacPherson struts with an anti-swaybar and strut tower brace, while the rear employs struts with a trailing link and twin lateral links per side plus an anti-swaybar.