<VV> STALL SPEED TORQUE CONVERTER

[James Davis]

The stock Corvair torque convertor is rated at 1,600 rpm static stall 
@ 100 ftlbs of torque input.  The 100 ftlbs comes from the rated net 
output of the 140 cuin, 80 hp engine.  More torque input will result 
in a higher stall speed.  A 3.1 ltr with mild cam will result in a 
1,935 rpm stall.  The Corvair torque convertor ceases to function as 
a torque convertor and becomes a fluid coupling at about 2,500 
rpm.  Torque converter slip (the measure of output/input rpm 
expressed as a percentage) at a particular load is measure of 
efficiency.  Generally, the higher the static stall rpm for a 
particular torque input the poorer the efficiency and the higher the 
heat output.  Generally, the higher the torque multiplication of the 
convertor the poorer the efficiency.  If an engine cannot reach its 
peak torque convertor stall rpm, then a higher stall rpm may help 
with initial acceleration (0 to 10 mph) only to be a liability at 
higher rpms.
The simple answer to (C) is it depends.  If your engine produces has 
its peak torque at 3,000 rpm or below, stick with  stock.
Jim Davis


   At 01:43 PM 11/13/2006, Michael Kovacs wrote:
>   Simple question. What does the stall speed impact?
>     A) gas mileage   advantage/disadvantage
>   B) acceleration   advantage/disadvantage
>   C) what is better for every day car, high or low stall speed.
>
>
>
>MIKE KOVACS