DRIVETRAIN • CONVERTERS

Choosing Converter Stall For A Heavy Truck

Why the number on the box is only a starting point, and how torque curve, truck weight, rear gear and tire size change what a converter actually does.

Advertised Stall Is Not A Fixed RPM

Hughes Performance explains that advertised stall ratings are nominal. Actual stall changes with engine torque, vehicle weight, rear axle ratio, tire height and converter design. In other words, the same converter can behave differently behind two different engines or in two different trucks.

Match The Converter To The Powerband

The goal is not “the highest stall you can tolerate.” The goal is to let the engine reach useful torque without making normal driving, heat control or lockup behavior worse than the application requires.

Published exampleConverter guidance
Texas Speed L92 Truck Stage 1 — 216/228, .600/.600, 113 LSAFactory-converter compatible.
L92 Truck Stage 2 — 220/232, .600/.600, 112 LSATexas Speed recommends 2800+ stall.
L92 Truck Stage 3 — 224/236, .600/.600, 112 LSATexas Speed recommends 3200+ stall.

Those are vendor-specific recommendations, not universal rules, but they demonstrate the relationship: as the cam pushes useful power higher, the converter requirement generally rises too.

Information A Converter Builder Actually Needs

Heat matters. More slip creates more heat. Plan transmission cooling and lockup strategy as part of the converter choice, especially in a heavy street truck.

Sources & Further Reading

These links are here so you can verify the numbers and go deeper into the original technical material.