cagotzmann

I am looking for a transmission to convert the TH350 to something else. The car (78) is used mainly for road track driving so overdrive or off the line doesn't do anything for me.

I would like a 5th gear a 1:1 ratio. (richmond 6 ROD) but they have not made any units in the past year, and may never build one again ????

So I was think about T56 units.
I would like a 5th gear to be a 3.08 final drive ratio.
So with a T56 5th @ .8 I would need a 3.85 rear gears so I guess 3.70 would be close 2.96, but is there a down side to having the wheels spin faster vs the transmission spin faster at a given speed.
I would think slower spinning tires would give more control, is the difference worth considering?.

The track I drive at has very slow and fast spots so I would like to use more gears than 2nd,3rd and 4th.

geerookie

Your wheels and tires will spin the same speed regardless of the transmission ratio or final drive ratio. Their rotational speed is determined by the circumference of the tire and the speed you are moving at.


Final drive ratio and top gear ratio only determine mechanical advantage or in other words, torque multiplication.

And another note, generally speaking the more you have to clutch and shift the slower you will be. (less acceleration = less speed)

Also, the more gears you have the more friction and rotating mass which slows acceleration. If you want 4 gears you will have better acceleration with a four speed and the proper ratios than a 5 or 6 speed even with the same ratios.
Figure out what you need for a final ratio at each point on the course you are working with and that will determine the actual gear ratio and rear end ratio you will need.