A lot of Factors come in to play. Driver being the biggest, wheel size and elevation not far behind.
Example. I ran a 15.85 at Norwalk in OHio at 90 degree wheather. At bristol, with 100degree wheather and higher elevation the best I could do was a 16.15. I also changed from my 17in Euro stars to stock 15's and cut 3 tenths(at bristol only). So, I could have run a 15.5 at Norwalk and could barely run a 16.15 at bristol.
Driver Example. I out ran a SVT by 4 tenths of a secound at Bristol. Thats a lot, my mods are all the Bolt-Ons and a tune (no cam gears). I dont know if I should have been that far ahead or not, I know I can keep up, and maybe out run, but 4 tenths is over 4 cars.
Turbod by - Myself
Tuned by - 03OrangeSVT, 1turbofocus, and Myself
Whp- 240 WTQ - 240