Drop in an MHD, JB4, bootmod3, or EcuTek CSV log. It finds loaded pulls, plots channels, and screens actual values against logged or entered targets. Everything runs in your browser; the CSV never leaves your computer.
A log records selected ECU channels, but it is only as reliable as the channel definition, sensor scaling, sampling rate, and test procedure. This page organizes the data and performs transparent target comparisons; it does not approve a calibration or diagnose a component.
There is no universal normal timing-correction number. Use this tool to locate and count events, then interpret them with the logger definition, factory strategy, calibration, fuel, and a qualified tuner. A correction channel cannot independently prove knock or identify a failed part.
The tool displays actual minus target and requires persistence before flagging a difference. The threshold is a screening rule, not a diagnosis; control strategy, throttle intervention, limits, sensor scaling, and operating conditions all affect the trace.
When a target is logged or entered, TunerBench reports sustained actual-minus-target delta lambda. Without that reference, it displays the measured value but assigns no pass/fail. Confirm whether the logger uses lambda, gasoline-equivalent AFR, or a fuel-specific AFR scale.
Compare start, peak, and change across tests performed under the same ambient conditions and procedure. Sensor placement, ECU compensation, vehicle speed, heat soak, and test duration affect the trace; use platform-specific limits.
The tool reports closed-loop trim averages and pressure minima. It only flags rail pressure when a commanded-pressure channel is available, and even then it reports a difference rather than naming a failed component.
Follow the vehicle, dyno operator, and tuner procedure. Perform loaded testing on a suitable chassis dyno or closed course with appropriate supervision, never where it risks public-road users. Keep gear, fuel, temperatures, configuration, and sampling consistent for comparisons.
Channel names are normalized across supported CSV formats; pull detection and persistence thresholds are documented heuristics. A target-comparison flag is not a diagnosis, tune revision, or safety approval. Verify channel mapping and raw rows before relying on any result.
CSV exports from MHD, JB4, bootmod3, and EcuTek work out of the box, and most other tools (Cobb, ProTune, generic OBD loggers) work too as long as the CSV has an RPM column plus throttle or pedal position. Column names are matched loosely, so "Boost (psi)", "ecu_psi", and "Charge air pressure" all land in the right slot. The file is parsed in your browser and never uploaded.
There is no universal normal value. Channel meaning, sign, filtering, ECU strategy, and acceptable behavior vary by platform and calibration. The tool reports magnitude, persistence, cylinder, and RPM for review against platform documentation or by a qualified calibrator.
Use the commanded target in the calibration or a value supplied by the tuner for the exact engine, fuel, load, and condition. TunerBench compares actual lambda with a logged or user-entered target. Without one, it displays the measurement and assigns no mixture pass/fail.
Fuel trims are ECU corrections whose definition and valid interpretation depend on operating mode and platform. TunerBench reports a closed-loop average when it can identify light-load samples. It does not use a universal healthy range or infer a component failure from trims alone.
A single log pattern cannot reliably distinguish a leak, sensor issue, calibration difference, or fuel-delivery problem. Compare actual values with commanded targets, confirm channel scaling, and use platform-specific diagnostic procedures. TunerBench reports correlations but does not assign a cause.
Some tools display gasoline-equivalent AFR and others use a fuel-specific scale. TunerBench attempts to infer the scale and normalize to lambda, but you must verify the logger and sensor configuration. Lambda comparison is only graded when a logged or entered target is available.
No. The CSV is parsed entirely in your browser and is not uploaded. When you share a report, only the compact screening summary is packed into the link; the raw rows stay on your machine.
Related Calculators
This contributor-authorized BMW B58 excerpt contains 113 recorded samples across 8.96 seconds. It is measured logger output, not our synthetic demonstration. The source identifies ECU Connect as the exporter, not MHD. Vehicle modifications, calibration details, fuel and test conditions have not been independently confirmed.
Read the pedal trace alongside actual and target lambda at the same elapsed time. The excerpt includes changes in pedal position; a whole-file minimum or average alone does not describe a sustained operating condition. Lines connect the recorded samples; no smoothing or resampling is applied.
Shared with permission for anonymized educational use. We selected one contiguous interval, reset time to zero and retained only eight numeric channels. VIN, filenames, dates, programming identifiers, comments and vehicle speed are excluded. Remaining readings are unchanged. This selection is not a representative assessment of all 23 supplied logs and is not a diagnosis or tune approval. Omitted knock, temperature and fuel-pressure channels must not be interpreted as zero or normal. The analyzer may use an assumed atmospheric pressure when converting absolute pressure; the source excerpt does not establish local atmospheric pressure.
A grade is a prompt to inspect the data, not proof that a tune is safe or that a component has failed.
Before emailing a log, remove identifiers and location data, confirm that you have permission to share it, and describe the specific question. Ask about private review first. Publication requires separate permission; we should never label a simulated trace as a measured vehicle test.