Re: stick shift Execs

Posted by Jack Vines On 2010/2/14 18:31:33

What was the rear gear ratio for the overdrive Clippers versus what was standard for the Twin-Ultramatic?

One big advantage for overdrive is using a lower rear gear for acceleration and having a higher gear for cruising. It makes all the difference in the world in the performance. The '56 Golden Hawk with overdrive had a 3.90 rear gear and 2.81 in overdrive. The T-U cars got a 3.07 rear gear.

Interestingly, on the street, the T-U extra torque multiplication actually showed some quicker acceleration numbers in magazine tests than the overdrive where axle windup and wheelspin was a chronic problem.

On the drag strip, especially when equipped with TwinTraction and TractionMaster bars, the overdrive was much quicker/faster. Some drag-only cars used 4.09 rear gears.

thnx, jack vines