Which track were you at? You can convert your high-altitude ET to a sea-level equivalent by using the NHRA Altitude Correction Factors that I posted in a spearate sticky thread in this section.
Using Fallon, NV's 4000' elevation as a comparison, your initial run of 16.522 @ 81.63 would translate at sea level to 15.712 @ 85.88 seconds if indeed the run was at 4000'.
