Help me settle an argument
I notice, the 650 is considered too small!! the fuel flow curve is where it's at.
in stock and super stock, they have to use the stock carb. they go very fast with "small" carbs!!!! the 69 340 cuda set the F/SA record, at 10.73,@ 120 MPH with a "small" AVS car. it's rated at 625 CFM. in super stock, the 283 chev has a 475 CFM rochester carb, the record is 128.11 MPH @ 10.20. they flog and tune , not change parts. just food for thought
NHRA uses horsepower
factoring to adjust the classes for their idea of "parity" in Stock and Super Stock ratings. Eons ago, cars were classified by their shipping weight divided by their advertised horsepower but that was so long ago I can't even remember when they changed to the "factored" horsepower system; probaby in 1972 when all the cars were de-rated to the then-new
net horsepower system. For example, the 318 2bbl motor was rated by the factory at 235 in 1971, and dropped to 150 in 1972 with NO mechanical changes. That's a whopping 56-percent!!!
Now, the NHRA assigns motors
factored horsepower ratings and the new numbers have a lot to do with your perception of how a car runs, with given equipment.
For example, the 1969 340 is factored to 299 hp, while the 1971 340 is factored to 314 hp, a difference of 15 horsepower, with only a carb change; an AVS vs. a Thermoquad.
But, that 15 horsepower in F Stock means that at 10.5 pounds per horsepower, the 1971 car has to weigh 10.5 X 15 = 158 pounds more than the '69. That's worth a car-length and a half.
So, the reason the record goes to the '69 may not be because it's putting out more power with the smaller carb, necessarily, but because it is legally 158-pounds lighter for the same class.
You can check on the factored horsepower for any engine that's legal for NHRA Stock or Super Stock cometition at NHRA.com. Go to "NHRA RACER" and the site will direct you from there to the "Stock Car Classification Guide."
At the very bottom of each column for the different hp engines, you'll find the factored hp. It's usually different for Stock (one asterisk) and Super Stock (two asteriisks) They have different hp for cars with (allowed) aluminum heads and... get this;
:wack:
the same engine MAY be factored to a different hp in two different bodies (go figure.)
It's a snake pit...
