Automatic Horsepower Factoring System

[Lynn A McCarty]

Originally Posted by SS Engine Guy

Thanks for those that took the time to read my long winded post. I am going to look at some numbers and see if I can come up with a suggestion. I really don't think there is one answer to the situation. And it probably won't please everyone. (or maybe anyone).

Part of what I am going to look at is the difference in cubic inches vs. et. vs, factored hp. vs. makers (Ford, GM, Mopar) within several SS classes and see if any correlation exists. This may apply or may not in Stock eliminator. It may offer a solution or it may only cloud the issues even more. The CIC suggestion may apply here, only in a somewhat different way than what is used in comp.
The problems that the AHFS is supposed to address weren't created in a day. I wish that someone had the answer that would make everyone happy, boost attendence, cause younger racers to get interested and migrate towards our catagories, and in general, make this all the fun that it used to be. Might even collect some sponsorship for our classes along the way. This can't be impossible. It will probably be hard but nothing worth having ever comes easy in life. I personally think that the AHFS is detrimental to our sport.

Here are some good equations: (not perfect, but good correlations)

HP(dyno) = 0.285 x CFM x 8(cyl)
0.240 for average bracket engine
0.250 for very good bracket engine
0.285 average factor for SS engine (low compression/high cubic inches a bit lower)
0.300 for high compression comp style engine
0.310 for very good comp engine

funny, where is the cubic inches in that equation?

Cylinder Head Choke Equation
CSA(min) = bore x bore x stroke x RPM x .00353/614(fps)
CSA = minimum cross sectional area of intake port
Choke = point at which velocity impedes horsepower

None of these are perfect, but we have been modeling them for the last few years and they make a lot of sense.

Using cubic inches in Super Stock isnt a good idea. There is a reason Hemis make over 900HP and 455 Olds make 600. If you look at the Choke equation it will tell you why.