98+ 3100/3400 Tuned ECM

1998–2005 GM 3100 / 3400 Derby Tune

This Custom ECM Derby Tune for 1998–2005 GM 3100 / 3400 engines is built specifically for demolition derby and off-road applications where factory limitations just get in the way.

We remove unnecessary electronics and modify the calibration so the engine will keep running even when things start getting hot and rough. This isn’t a stock-style tune — it’s designed to simplify the system and keep the engine alive when conditions aren’t ideal.

What This Tune Does

✔ Optimized ignition timing and fueling for better performance
✔ Raised rev limiter
✔ Temperature limits increased so the engine can run hotter
✔ Factory security system (VATS) removed
✔ Unnecessary sensors disabled to reduce shutdown issues

Compatibility

• 1998–2005 GM 3100 / 3400 V6 engines

Works with:

• Factory wiring harness
• LMMF Simplified Standalone Harness

Installation Notes

If using the factory wiring harness, you will need to:

• Install a push-button starter
• Hotwire the fuel pump

For the easiest install, we recommend pairing this tune with an LMMF Simplified Harness, which eliminates most of the factory wiring.

For demolition derby applications, it is also recommended to hotwire the transmission.

Pair this tune with an LMMF Party Mode Box and an LMMF Simplified Harness, and you might as well start building more shelves… because those trophies are going to start stacking up.

⚠ For off-road use only