do stall converters help any at all from a roll??? are they just for launching??

 

Yes, they definitely do help from a roll as well. Not as much as they help from a launch (if you can get traction), but they do help. Quite a bit at times.

 

They help especially when you don't have a proper shiftpoint
setup (like, stock); the converter will at least let the motor
slide on up into the powerband instead of lugging. It helps
cover up the so-called "dead spots" (which are really just
stupid no-kickdown regions in the shift tables).

 

The dead spots are more than just the no kickdown regions. First gear is 3.06 and second gear is 1.62. If you shift at 6000 rpm, the motor (w/o a converter) would drop down to mid 3000s (3200 rpm plus the benefit of residual acceleration during the shift). A good high stall converter will keep the engine rpms above 4400 rpm and thus keep the car in the heart of the powerband. There will also be some torque multiplication created until the slip ratio closes back up. This is more than the stock converter provides, which is a few hundred rpm of slip.

An efficent 3500 or higher converter will make a noticable improvement from a roll.

 

When my car shifts, it goes to 4800 rpm. A very big difference than stock.