How Quicktune works
On an Elite ECU, each cell of the fuel base table sets injection time for one rpm and load point. When you press Q, ESP looks at the measured AFR from your wideband and the value in the target AFR table for that point. It works out the ratio between them and scales injection time up or down by a matching amount. If the engine is 10% leaner than target, the cell gets roughly 10% more fuel.
That's the whole trick. It does the arithmetic you'd otherwise do in your head, and it does it instantly. Deciding whether the target is right, and whether the data was good, is still up to you.
What you need first
- A calibrated wideband input. Quicktune won't run without one. A Haltech wideband controller is the easiest option, and our wideband O2 sensor article covers the Elite setup. Third-party controllers with a calibrated 0-5V analog output also work: Innovate, FJO, AFX, M&W Ignitions and Tech-Edge are among the brands that offer one.
- The right calibration. If you're using an analog wideband on an auxiliary input, set it under Setup → Sensor Setup → Calibrate Sensors → Wideband O2 Controller, and match it to the controller's documented output. A wrong calibration means Quicktune chases the wrong number.
- A sensible target AFR table. Find it in the ECU Navigator tree and fill it with the mixtures you actually want at each load before you start. Quicktune will hit whatever target you give it, safe or not.
- A load source. A steady-state dyno is ideal. See applying load to the engine for your options.
Using the Q key properly
- Open the fuel base table you want to tune.
- Bring the engine to the rpm and load you want, and hold it steady close to the middle of the cell.
- Let the AFR reading settle.
- Press Q once.
- Wait for the new mixture to reach the sensor and the reading to settle again. Then decide whether it needs another press.
Two things trip people up here:
- Q only changes the cell you're operating in. It ignores any cells you've highlighted. And if the engine is between cells, the ECU is blending several of them, but Q only fixes one. Staying centered is what makes the result stick.
- Don't machine-gun the key. There's a delay between changing injection time and seeing it on the wideband. Tap Q three times in a second and you'll apply three corrections for the same error, and the cell swings well past target. One press, wait, check.
Each press is also capped at ±30% change. If a cell needs more than that, something bigger is usually wrong: injector data, fuel pressure or a sensor.
The W key: spreading the correction
Pressing W takes the injection value Quicktune just calculated and copies it forward: into the next load cell to the right, and into the matching two cells in the next rpm range up. It's a quick way to pre-fill the cells you're about to move into, so the engine isn't wildly off when you step up in load or rpm. Treat the copied values as a starting point. You still tune each of those cells properly when you get there.
Where Quicktune fits in a full tune
| Stage | Our advice |
|---|---|
| Idle and light load | Works well once idle is stable. See tuning for idle (fuel) |
| Cruise and part throttle | Quicktune shines here on a steady-state dyno, one cell at a time |
| High load | Use it, but confirm with logged runs. Don't hold the engine at high load longer than you need to |
| Transients | Don't Quicktune during throttle changes. That's a job for transient fuel settings |
For the order we fill the tables in, read tuning base tables. Running a Nexus instead? Its version adds cell tracing and applies corrections to a whole drive at once. See Quick-Tune in NSP.
Running a car on a rough map can damage an engine. Get the fuel table safe before you touch ignition. When you do tune ignition, start with conservative timing and add it gradually, and stop immediately if you hear or detect knock.
Quicktune FAQ
Why did Quicktune make my AFR worse?
Usually the engine wasn't steady, it was between cells, or Q was pressed before the wideband caught up. Hold the point, wait, then press once.
Can I use a non-Haltech wideband?
Yes, as long as it has a calibrated 0-5V output and you enter the matching calibration in ESP.
Does Quicktune set ignition timing?
No, it only adjusts fuel. If you'd like us to handle the tune, get in touch.
