Tuning
Tuning a Truck That Actually Tows
A great many of the trucks we see from Valrico, Riverview and the east side tow something regularly. A calibration written for wide-open-throttle pulls is not the same calibration a towing truck wants, and running one is how transmissions die.
Towing is a completely different load case
A performance pull is short, high load, and then over. Towing is sustained moderate-to-high load for hours, at highway speed, in Florida heat, with a trailer adding drag and mass.
Everything thermal is worse. Transmission fluid temperature, engine oil temperature, coolant, intake air, and differential temperature all run higher for far longer than they ever do in a performance context.
Transmission calibration is the priority
On a modern truck the transmission tune matters more to survival than the engine tune does.
- Line pressure — adequate clamping force so clutches hold rather than slip. Slipping clutches generate heat and heat destroys them.
- Shift timing and firmness, which determines how long the clutch is in transition and therefore how much heat each shift generates.
- Torque management, which limits engine output during shifts to protect the driveline.
- Torque converter lockup strategy, which is where an enormous amount of towing heat comes from. An unlocked converter under sustained load is a heat generator.
- Gear selection strategy, so the truck is not hunting between gears on a grade.
Transmission fluid degrades with temperature, and degraded fluid does not protect the clutches. A truck that tows regularly in Florida should have its fluid on a shorter interval than the manual suggests, and cooling capacity is worth spending on before power is.
Engine side
Power targets on a towing truck should be set with sustained load in mind rather than peak. Torque low in the rev range is more useful than horsepower high up, and a calibration with more knock margin is worth having on a truck that will spend an hour at high load in August.
Cooling comes first
- Transmission cooler capacity, and a temperature gauge you actually look at.
- Engine oil cooling on anything working hard for extended periods.
- Radiator and airflow, which is the constraint at low speed on a grade.
- Differential cooling on heavier applications.
What we will tell you
If a power target is not compatible with towing on the hardware present, we will say so rather than write the calibration and let the transmission find out. That is a conversation worth having before the work rather than after.
Keep reading
Bolt-Ons and Tuning: What Order Actually Makes Sense
TuningDatalogging: The Numbers Worth Watching on a Modified Car
TuningKnock: What It Actually Is and Why It Ends Engines
Talk to us about your build
GZ Performance LLC — 6717 Benjamin Rd, Building 640, Tampa, FL 33634. Tuning, turbo and supercharger installs, engine builds and swaps, brakes and suspension.
Call (786) 718-5573 Request an Estimate