The 1981 had a 301 cu in V-8 -close to 4.9L- and, was not in the same class of performance as the later TR's and 20th Anniversary TTA, or GNX
You can find more at the TTA website. Search for "1981"....Here
I know of only one documented dual between a TTA and GNX in completely stock form. It was pretty even, with the GNX winning two of three runs (if my memory is correct). The two cars went through eliminations later that same day....The TTA won the class Of course, a TTA will never be a GNX
The magazine writers report 16-17 second ¼ mile times. Better gas, a boosted launch and decent tune should get them into the 15's, IMO. Then, like any turbo car, they have potential to get faster with more boost.