computer engine builder program

Dart1966 is correct. Desktop Dyno figures things in a perfect world which are rarely achieved unless your spending big bucks to have every last thing blueprinted. I have it and when I play with it I figure in a fudge factor of 5-8% and that's when I have the heads flowed to put in the actual flow figures rather than just pick a head file in the program.

If you don't have head flow numbers you can go to http://users.erols.com/srweiss/tablehdc.htm which has hundreds of head flow files so you may find the heads you have and can input the numbers to make the HP estimate more accurate.