off the 2+2 chassis for the extra wheelbase. It got me curious, so I tried to do some digging. Not a whole lot of info out there, but the 2+2 is supposed to have an almost 50/50 balance and with the extra wheelbase - be less twitchy and roll slower (yaw) in the turns. It seems the 2+2 was/is preferred by all the Japanese tuners as well.
90 Twin Turbo Track Build - jsworks.org for more info!