Difference in stall speed related to stress?
Thread Starter
Staging Lane
Joined: Feb 2006
Posts: 69
Likes: 0
From: Cleveland Ohio
Difference in stall speed related to stress? Would there be much of a difference in the amount of stress put on the transmission driving in traffic on the street depending on the stall of the converter? Would a ~3000 stall put less strain on the transmission than a ~4400 stall? Im not going to have any chance of burning up my transmission DDing, am I? BTW, this is a built 4L60E and shift kit. The engine will have a 233/239 TSP cam, LS6 Stg 1 heads, and 3.73's out back.
The higher stall speeds tend to also have a higher
STR so you multiply torque more. Direct increase
in input shaft torque. Further, you are guaranteed
to be up on torque peak (vs the stocker which will
hold you down to well less; the 3000 and 4400 are
both liable to be near peak torque).
A 3000 is often seen about 2.0 - 2.2 STR while a
4400 is likely to be 2.7 or more. The stocker is like
1.8 or so.
I would expect there to be maybe 20-25% higher
input shaft torque applied, 4400 vs 3000. Relative
to stock you will put 2X the torque to the box,
between being up on the torque flat-top and the
higher torque multiplication (STR).
STR so you multiply torque more. Direct increase
in input shaft torque. Further, you are guaranteed
to be up on torque peak (vs the stocker which will
hold you down to well less; the 3000 and 4400 are
both liable to be near peak torque).
A 3000 is often seen about 2.0 - 2.2 STR while a
4400 is likely to be 2.7 or more. The stocker is like
1.8 or so.
I would expect there to be maybe 20-25% higher
input shaft torque applied, 4400 vs 3000. Relative
to stock you will put 2X the torque to the box,
between being up on the torque flat-top and the
higher torque multiplication (STR).
Jimmy's framework is correct, but that applies to WOT launches. For daily driving at typical part throttle acceleration levels, there's no real difference except for the heat load which requires a cooler
FWIW I ran a 4400 (flash-stall) converter on a small-block mopar street car for about 2 years with absolutely no problems. With a proper cooler you should not have any problems.
