Rotor selection based on weight.

[DaveR]

Excaliber,

You have a good memory, 3 to 1 it is. Herb Adams thought this was important enough to include a chapter (chapter 15, "Rotating Inertia") in his book "Chassis Engineering". He has a chart showing eqivalent horsepower and speed at the end of 1/4 mile with 15 pounds of static weight versus 15 pounds of rotating weight. He goes on to say that weight reduction of rotating weight at axle speed is 3 to 1, but weight reduction of rotating weight at engine speed (anywhere in the driveline) is 15 to 1, amazing! Reading his book put me in a quandry and brought me to the board for input from the experts so I could reconcile race theory for people trying to shave tenths, from Cobra reality.

So, a ten pound difference in the 2 front rotors is like having a 30 pound weight on the hood. Seems like it offsets the advantage of a set of aluminum heads. I'm still not sure what to do, however, I did notice that the rotors on the race car pictures in his book are HUGE!