Chassis info
 

Just posting this so I can find it later.. this is straight from the 1998 Supplement to the 1997 986 Factory manuals.


Bodyshell reinforcements are used in the rear end of the vehicle.

The following metal panels have been modified:
Wheel well with spring strut mount, engine compartment bulkhead, lower rear-wall cross member, and reinforcements for the rear axle mount. 18 inch wheels are not permitted unless these reinforcements have been fitted.