Whats my Gear ratio?

[uskatebetter]

so I have a 69 charger with a 318 and i was just wondering what my gear ratio is since well..........hahah i dont know.

oh yeah i know my car has posi trac, but i was also curious to what kind it is?

thanks guys.

[694spdRT]

Jack the rear end up and spin the tires one revolution while counting the # of revolutions the driveshaft makes. If it turns 3 1/4 you have 3.23's, 3 1/2 they are 3.55's, etc. 

Make sure both tires are turning the same way and Posi Trac is Chevy...Mopar is Sure Grip. 

[73chgrSE]

 ???Just wondering. Why is it better to have a higher # as opposed to a lower one. It seems like awith  a lower # the driveshfat spins twice to get one tire spin of travel but at a higher # it has to spin 4 times to move the tire the same amount. It seems like twice the work from the motor for the same distance. I guess I don't understand the physics or my math is backwards. Could someone please explain this to me?

[694spdRT]

Read this link when you are bored. 

http://www.heumann.com/m5/hp_torque.html

Basically gears are a torque multiplier. I think Firefighter or Chryco had a table showing torque multipilcation vs rpm. As an example a 4.10 gear will exert twice the torque at a given rpm than 2.05 gears.

[dodge freak]

Go get yourself a 10 speed bike and ride around using all the gears then you will understand.

[73chgrSE]

Read this link when you are bored. 

http://www.heumann.com/m5/hp_torque.html

Basically gears are a torque multiplier. I think Firefighter or Chryco had a table showing torque multipilcation vs rpm. As an example a 4.10 gear will exert twice the torque at a given rpm than 2.05 gears.

Thanks, that shed some light on it for me. Awesome artical.

[73chgrSE]

Go get yourself a 10 speed bike and ride around using all the gears then you will understand.

Haha!!  I have a 21 speed and that's some confusing sh*t!