[silver_pilate]

Good explanation of some confusing terms, 88Cobra.

A torque converter works similar to the clutch in a T-5. It takes the output of the motor from the flywheel and transfers it to the transmission. However, instead of using a friction plate like a clutch, it uses fluid dynamics and viscosity to couple the engine and tranny. The converter has blades in it similar to an impeller. The blades spin submerssed in the transmission fluid. The fluid provides resistance against the blades. The faster they spin, the more the resistance. Eventually, the resistance is so great that the tranny and engine are essentially coupled together. This is the true stall speed.

Converters are built with a little "slip" in them to allow the engine to rev up closer to its powerband. Otherwise, the one-to-one coupling would bog the motor off the line every time because the motor doesn't make enough power at 600-700 rpms to move the car forward. The stock converter essentially lets the motor rev up to around 1500 rpm's before the resistance of the fluid "locks" up the converter. This is still considerably short of the stock or modified 302's powerband. Therefore, when you floor it, the engine surges strong, then suddenly bogs down a bit when the converter reaches its stall speed and locks up only to come back strong at around 3000 rpm. This was the way my AOD always acted. When you install a higher stall speed converter, it allows the engine to reach its powerband more quickly before the converter locks up. A 2800 rpm converter puts you right at the beginning of the powerband, thus eliminating the bog.

A higher stall speed converter is absolutely one of the best modifications you can make to an AOD car. The converter, coupled with sufficiant gearing transforms the mundane AOD into a fun and considerably quicker off the line vehicle to drive.

--nathan