Guys, as you all know I'm a rookie when it comes to High Performance/Drag racing stuff.

I think I understand what torque conv. stall speed, break stall, etc. are, or at least I know the basics.

What I haven't figured out is what the number of inches signifies and how it effects stall speed, efficiency and performance.

What do these dimensions refer to and what is better for what?

Thanks,
Enrique.

They are a non-standard means of trying to catagorize the converter diameter. They are not the actual dimension of the outer shell, but often are closer to the diameter of the turbine inside the converter. Generally the smaller the diameter of a converter the more potential it has for higher stall speed. As a very, VERY general rule of thumb, each increase or decrease in size by 1" will raise or lower stall speed by 500-700 rpm.....IF the fin angle and stator remain the same. Fin angle directly relates to stall speed and efficiency...negative fin angles are not condusive to good efficiency, while positive ones are. Each 50 of fin angle change positive will lower stall speed by about 200 rpm, while each 50 move negative will up stall speed about 200. Many street converters use a cut stator which will take some torque multiplication away to help guard against excessive tirespin on street tires. If you have one of the C stators that has been cut to modify it to the CCX type, and then were to swap it out for an uncut C version, you will drop 500-700 in stall speed, but have a more agressive torque multiplication factor. You pretty much control stall and efficiency through physical converter size and core brand, along with stator type, and fin angle. Hope this helps!