Draglist.com Drag Racing

I had this laying around and thought it might be interesting to some. This is how you calculate your Final Drive Ratio off the starting line.

If you have trans gear ratios of:

1st Gear = 1.31

2nd Gear = 1.38

3rd Gear = 1.00

Rear Gear Ratio of 3.90

You take the gear ratios and multipy them:

{1.31X1.38}=1.81 is your First gear ratio

Then take the first gear ratio times the Rear Gear ratio and that equals your Final Drive Ratio:

1.81 X 3.90 = 7.06

So your Final Drive Ratio is 7.06

I thought I'd note that you're assuming a Lenco, where each section has a gear ratio and you put it in low by running through the accumulation of all of the sections.

If you have a standard tranny, or a TH400, or something similar, the ratios in each gear are usually stated directly because the tranny is only in 1 gear at a time. In this case, you don't multiply all of the gears together, you just use the low gear ratio x rear ratio.

Perry

Perry, you are correct. I should have stated that in my post. We run a lencodrive in our car. The info is for that or a Lenco trans. Sorry,

Rapid

no problem Randy. I understood, but I wanted to make sure no one else was confused.