My wife has a 1996 mtx cavalier coupe, not the z24 and it is pretty quick. I'll bet I could run high 16's in the 1/4. I would not doubt the z24 is worth high 15's.
P.S. I thought the recorded 0-60 time for the 98 svt was 7.1 and 99-2000 was 6.9, so why do I always here it is 7.9? I hear that quite a bit. there is no way a stock low-mid 15 second quarter-mile car is running an 8 second 0-60.
