Transmission options

[Huskymaniac]

Originally Posted by Ironhydroxide

Well finding Gear ratio's isn't hard. and calculating ratios and speed isn't hard either... SO. I guess i need that Dyno for the Stage 1.

Even better, I found the original specs which say that peak torque occurs at 4400 RPMs. The stage 1 car on the dyno peaked at 4500-4600 RPMs. If you want that to correspond to, say, 75 MPH it would be a wicked low gear ratio. That would point to the 4.44 being your best option for fuel economy. But, again, I have no idea if it is true.

EDIT:

I'm sick but now you made me go and think. It occured to me that there may have been an assumption I was missing and now I may see the logic behind this claim that peak torque and peak efficiency occur at the same RPMs. Here goes:

Power = Torque * 2 * PI * RPM

Assumption: Rate of air and fuel consumption at a given throttle position is proportional to RPM or Fuel Consumption Rate = constant * RPM. Let's call that FCR.

Power is energy used per unit of time and fuel consumption rate is fuel used per unit of time. Efficiency would be energy obtained for a given amount of fuel so efficiency would be power divided by fuel consumption rate or Efficiency = Power / FCR = (Torque * 2 * PI * RPM)/(Constant * RPM) = Torque * 2 * PI / Constant

So efficiency should be torque multiplied by a constant and should peak when the torque peaks. This has a big assumptin built into it but maybe it makes sense.