Slow Z?
15.1 is a very slow ET for a stock LT1 but there's factors involved such as the DA, whether you have 2.73 gears or 3.23s, mechanical condition of your car, your 60' time, etc. What was your mph? That's a more realistic picture of the car's performance. For comparison my auto 3.23 gear LT1 ran 13.9 at 99 when stock with some nasty wheel hop and my buddy went 13.5 at 102-103 with his auto 3.23 gear LT1 with catback only. High 13's to low 14's are to be expected for a proper running auto LT1 car in reasonable DA. Do you have 2.73s? If you do, that's not helping. If your gear selector does not go lower than "2" you have a 2.73 car, if your gear selector shows a "1" you have a 3.23 car. Also, if you raced in Colorado with awful DA then your time of 15.1 wouldn't be as bad with the weather conditions corrected for. The hypertechs don't do anything for these cars, I'd suggest ditching that for a mail order tune from Moe Bailey. Post up in the LT1 section if you've got any LT1 specific questions, many of us of us over there have owned these cars for 10-20 years and can help you wake that thing up.
