General · May 2, 2025

Pre-Tuning Checklist

Electrical, fuel, mechanical, turbo, and ignition checks to run before a tuning session so the map is not chasing a broken car.

Things to ensure you have a good tuning session. Fix the car first; then calibrate it.

Electrical system

Wiring: Ensure all engine harness wires are insulated. Solder or crimp connections. Do not twist wires together.
Grounding: Clean chassis grounds to bare metal. The battery ground cable should be equal to or larger than the power cable.
Voltage: Maintain 13.5–14V when the engine is running so charging issues do not masquerade as a lean or knock problem.

Fuel pumps: Clean the gas tank before installing in-tank pumps. Use a pre-filter (40–75 micron) and a post-filter (100+ micron) on external pumps.
Fuel pressure: Set base pressure between 40–50 psi. A fuel pressure gauge or sensor is worth having so you can see it during the session.
Regulators: Upgrade OEM regulators when you step up to high-flow pumps. Returnless systems may need conversion for high-boost work.
Preparation: Secure vacuum lines and start with at least half a tank of fuel.

Engine: Verify compression across cylinders (no more than 20 psi variance). Check and top off oil and coolant.
Timing: Confirm the timing belt or chain is installed correctly. Wrong cam timing will waste the whole session.
Clutch: Use a clutch rated for your power goals, and follow the manufacturer break-in if it is new.

Boost leaks: Perform a boost leak test. Tighten every clamp and fitting.
Vacuum lines: Route wastegate and blow-off valve lines correctly. Plug unused ports so they stay plugged.
Boost control: Use a 3-port solenoid for EMS-controlled boost. Confirm the wastegate spring is in the right range for the target.
Exhaust and intercooler: A 3″ or larger exhaust helps. A front-mount intercooler is the usual upgrade when the stock core is out of air.

Spark plugs: Step one heat range colder for performance work. Gap 0.021–0.028″ on forced induction.
Maintenance: Short trips that never reach operating temperature foul plugs. Get the engine fully warm before you start pulling timing.

Automatic transmissions: Confirm the transmission can stay locked in the gear you need while you tune.
Wheel lugs: Torque the lugs before you drive, especially if the session includes hard pulls.