i am finding that these calcualtors are all over the map....my car is 2420 with me in it and i have only 3 passes on my new motor...it ran a 9.76 @ 137 mph.....every calculator using that info has predicted a different horsepower...anywhere from 577 up to 668 horsepower at the flywheel,and 480-525 at the rear wheels...and thats just too major a difference to determine what is accurate.....if i plug all the engine specifics into the dyno computer software,including all the cylinder head flow figures,it predicts a max hp of 543 @6500 rpm.....
i guess the only way to be sure is to spend the 400.00 and drop her on a real dyno for the day...i had my spare motor dynoed and the info that i recieved was extremely usefull........probably saved me 2-3 weeks of tweaking at the track.
the biggest things that stood out when i had my spare dynoed was
-the amount of oil in the pan affected horsepower and oil pressure...the more oil in the pan,the lower my oil pressure and the less horsepower it produced over 4500 rpm
-cam timing didnt seem to affect peak horsepower,but it moved my peak torque around in the rpm band....i wanted more bottom end torque,so using the dyno i was able to adjust cam timing so it increased torque where i wanted it....valve lash was a big factor in torque as well
-total timing was a big factor in hp....felt safest at 36 degrees,but made most power/torque at 40 degrees
-header tube size was a big factor in hp....going from a 1/78 header tube,to a 2 inch header tube increased hp across the board by 30 hp
-this motor isnt a tpi...its carbed....put a 2 inch carb spacer on and it increased hp by 20 from 3800 rpm up.
it was amazing how much small things affected the way the motor performed,and how some big things didnt change a thing....either way it was 400.00 well spent
