WrxBuild.com Service & Build Log

SEC 04 · Procedure

Protune Prep: The Checklist Tuners Wish You'd Follow

A dyno tune is only as good as the car you bring. The mechanical checklist that stops you from paying for a diagnosis session instead of a tune.

Procedure

  1. Boost-leak test the entire intake tract at your target boost. A tuner finding your leaks at $150/hour is the most expensive soap bubble test in history.
  2. Fresh plugs at the correct heat range and gap - one step colder if you're raising boost meaningfully. Old plugs mask as tuning problems.
  3. Verify fuel delivery basics: pump health on a datalog (fuel pressure or injector duty under load), and fill with the exact fuel you'll run daily. Tune on 91, run on 91.
  4. Fix every mechanical issue first: no CELs, no boost-control gremlins, no exhaust leaks - a pre-turbo exhaust leak skews the front O2 sensor and ruins the tune.
  5. Log a baseline third-gear pull (safely, or on the dyno) and email it to the tuner ahead of time with your full mod list. Surprises on the mod list waste dyno hours.
  6. Show up with a healthy battery, decent tires, and half a tank - dyno straps and wheelspin don't mix with worn rubber.
  7. After the tune, log your first week of driving and send the tuner a knock/fuel-trim summary. Every good protune includes a revision - use it.

Work at your own risk. Torque values and procedures vary by vehicle — always confirm against the factory service manual for your exact model.

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