Wallace Racing has a calculator for HP and ET based on inputs you provide.
ET-MPH-HP Calculator
My 340 Formula S FB ran a best of 13.48 @ 105.38 pure stock with a A727, 3:55 gears, and H70x14 tires. This was essnetially at sea level in SoCal (OCIR, Lyons, Irwindale, Pomona, etc). The car weighed about 3200 and I weighed about 185 so total weight was 3385. Using the MPH/Weight estimator, I get 305.23 HP. This is the best estimate as using the ET/Weight estimator is a function of traction and ability more than engine power. Using
[email protected] in the calculator yields 273.13 HP. If you put the 305 HP into the top equation which estimates ET and MPH, you get 12.99 @ 104.04 MPH. This is what a car should do with optimum traction and driving skill so it shows how much improvment is possible with the power you have.
Fun and useful information to play with.