All logic would point to it being a Carrera, the non-turbo 911. It does 0-60 in about 5 flat, and 1/4 mile in mid-high 13s. So basically a stock TT Z should hang with a carrera.. And your passenger side turbo was going, so that's why you fell back :) I don't blame you at all though - it's nearly impossible to tell a 911 turbo and non-turbo apart without seeing the 'turbo' emblem on the back of the turbo. Boxster too from the front is hard to tell apart from 911s at a distance (newer ones I think)! They just changed its fascia again though..
Kez
"Pulled the blower fan down from behind the glovebox and there was a mouse nest inside the cage fan - mom and 6 babies. Mom was dead and the reason for the smell - petrifying fast - but the babies were hanging on. At least until I fed them to the cats." [ZXtaZTT - June 19, 2002]