Weekly Digest: November 18–22, 2025

Highlights

epicEFI Firmware Changelog — Comprehensive changelog of all epicEFI features through September 2025
AFR vs Lambda — Understanding fuel target units in epicEFI
MAF Sensor Tuning Basics — MAF transfer functions, MAF/MAP blend mode
Rotational Idle — Programmable ignition skip patterns for smooth idle

Technical Discussions

AFR vs Lambda internals: How epicEFI handles Lambda 1.0 internally and converts to AFR for display, why stoich varies by fuel type (14.7 gasoline, 9.8 E85)
VE and ignition table setup: Beginner guide to configuring VE tables, ignition timing, and understanding MAP-based load axes
MAF/MAP blend: Running both air metering models simultaneously with configurable weighting per operating point
Lean cruise strategies: Running Lambda 1.05–1.10 at light loads for fuel economy, timing compensation for lean mixtures

Hardware & Wiring

EPIC CAN Bus: External device control via CAN bus protocol for dash integration
ETB TPS redundancy: Toyota throttle body dual-TPS modes and failsafe behavior

Feature Spotlight

Rotational Idle: A unique feature that skips ignition on specific cylinders in a rotating pattern to reduce idle vibration without lowering RPM

Weekly Digest: December 1–7, 2025

Highlights

[[../2025-12-02_tcu-transmission-control.md|TCU Transmission Control]] — Automatic transmission control for Toyota A340 and similar

Technical Discussions

Transmission control: epicEFI's TCU supports simple solenoid-based automatics (one solenoid changes per shift), with input shaft speed sensing for shift timing
Line pressure tuning: Firmware-based shift firmness control replicating aftermarket shift kit behavior
Gear range limiting: How the manual selector lever's hydraulic limits interact with TCU firmware

Support & Troubleshooting

General tuning discussions and community support throughout the week

Weekly Digest: December 8–14, 2025

Highlights

[[../2025-12-08_ve-table-map-multiply-explained.md|VE Tables and MAP Multiply]] — Why VE tables have curved shapes and the math behind it

Technical Discussions

VE-to-MAP relationship: Detailed experiment showing the 1/x inverse relationship between MAP and required VE compensation, explaining why VE tables are non-linear
Choked vs non-choked flow: Airflow behavior changes at ~52 kPa, making idle-region VE tuning especially tricky
Injector dead time tuning: Using epicEFI's sequential/batch switching tool to precisely calibrate injector dead times, signs of incorrect dead times, and why most enthusiasts skip this step

Key Numbers

VE at 25 kPa needs ~400% to match 100 kPa baseline
Flow behavior changes at ~52 kPa (choked flow threshold)
Dead time errors show up as AFR differences between sequential and batch firing modes

Weekly Digest: January 1–7, 2026

Highlights

[[../2026-01-05_epictuner-alpha-release.md|EpicTuner v0.1.0-alpha]] — First alpha release of the cross-platform tuning application

Feature Updates

EpicTuner alpha release: Modern cross-platform tuning software by @sangawku supporting Windows x64, macOS ARM64, and Linux x64
Key features: drag-and-drop dashboards, 2D table editor with 3D visualization, curve editor, real-time data streaming, built-in logging
Portable application — no installer needed, reads INI directly from ECU
Aims to provide TunerStudio paid features (VE Analyze, composite logging) as standard for epicEFI users

Weekly Digest: January 8–12, 2026

Highlights

[[../2026-01-08_first-start-troubleshooting.md|First Start Troubleshooting]] — 4G63 cranking troubleshooting, acceleration enrichment, MBT timing
[[../2026-01-09_firmware-variable-access-lua.md|Firmware Variables in Lua]] — Accessing firmware variables via Lua and output channels
[[../2026-01-10_injector-decapping-reference.md|Injector Decapping Reference]] — Bosch/Denso/Deka injector identification, Honda coil dwell
[[../2026-01-11_pcb-design-ecu-boards.md|PCB Design for ECU Boards]] — Layout rules, crosstalk prevention, ground pour strategies

Technical Discussions

4G63 first start: Step-by-step troubleshooting from cranking through idle, including trigger sync, fuel prime, and acceleration enrichment wall-wetting model
Lua firmware access: How to read/write firmware variables from Lua scripts, with BMW CAN torque example
Injector identification: How to identify unmarked injectors by decapping and examining internal structure

Hardware & Design

PCB best practices: Trace spacing rules for high-current paths, crosstalk prevention between signal and power traces, ground pour debate (full pour vs strategic routing)

Weekly Digest: January 13–19, 2026

Highlights

[[../2026-01-13_wideband-lambda-sensor-setup.md|Wideband Lambda Sensor Setup]] — 14point7/Spartan wideband configuration for E85
[[../2026-01-14_acceleration-enrichment-predictive-map.md|Acceleration Enrichment & Predictive MAP]] — AE tuning strategies and predictive MAP model
[[../2026-01-16_new-user-onboarding-m144h7.md|M144H7 Onboarding]] — Getting started with M144H7 boards
[[../2026-01-17_user-tables-arbitrary-variables.md|User Tables]] — Arbitrary variable lookup tables for custom corrections

Technical Discussions

Wideband for E85: Configuring 14point7/Spartan widebands for flex fuel, free-air calibration procedure, sensor conditioning
Predictive MAP: How the ECU predicts manifold pressure during transients for better fueling before the MAP sensor catches up
DFCO: Deceleration fuel cutoff configuration and re-engagement strategies

New User Support

M144H7 board setup: Pin mapping, firmware variant selection, EGT sensor wiring, SD card logging configuration
User Tables feature: Creating custom correction tables with arbitrary X/Y axes selected by variable hash

Weekly Digest: January 20–26, 2026

Highlights

[[../2026-01-24_custom-trigger-wheel-design.md|Custom Trigger Wheel Design]] — Trigger wheel tooth patterns and BMW N63TU cam sync
[[../2026-01-25_hall-sensor-trigger-edge-and-tune-corruption.md|Hall Sensor Edges & Tune Corruption]] — Hall sensor edge selection, corrupt tune recovery

Technical Discussions

Trigger wheel design: Choosing tooth count and missing tooth patterns, how the ECU achieves sync, BMW N63TU twin-turbo V8 cam sync challenges
Hall sensor edges: Rising vs falling edge selection for Hall-effect sensors, how incorrect edge selection causes timing errors
Tune corruption: How corrupt Lua scripts in MSQ files can brick the ECU config, firmware backup architecture and recovery procedures

Weekly Digest: January 27 – February 2, 2026

Highlights

[[../2026-01-28_can-bus-protocol-reference.md|CAN Bus Protocol Reference]] — 0x701/0x721 protocol details, virtual outputs, tune database
[[../2026-01-30_vanos-vvt-calibration-procedure.md|VANOS/VVT Calibration]] — BMW M54 VANOS procedure using epic_can_proxy
[[../2026-01-31_etb-setup-guide.md|ETB Setup Guide]] — Electronic throttle body configuration, VR sensor polarity

Technical Discussions

CAN bus protocol: Detailed reference for epicEFI CAN message IDs 0x701 and 0x721, virtual output configuration for CAN-controlled devices
VANOS calibration: Step-by-step BMW M54 variable valve timing calibration using CAN serial proxy for remote tuning
Tune sharing database: Community effort to build a shared database of known-good tunes for common engine configurations

Hardware & Setup

ETB configuration: Electronic throttle body setup procedure including auto-calibration, pedal mapping, and PID tuning
VR sensor polarity: How to verify VR (variable reluctance) crank sensor polarity and the consequences of reversed wiring
Ignition cut warning: Using ignition cut as an over-rev warning before hard rev limiter

Weekly Digest: February 3–9, 2026

Highlights

[[../2026-02-04_acceleration-enrichment-async-fuel.md|Async Fuel AE Strategy]] — New acceleration enrichment approach using asynchronous fuel injection
[[../2026-02-05_sensor-grounding-best-practices.md|Sensor Grounding Best Practices]] — GND vs GNDA, H7 power requirements
[[../2026-02-08_epictuner-troubleshooting.md|epicTuner Troubleshooting]] — Common epicTuner issues, ETB manual calibration, YoloSync
[[../2026-02-09_wideband-o2-heater-management.md|Wideband O2 Heater Management]] — Bosch heater profile, OEM vs aftermarket controllers

Technical Discussions

Async fuel AE: New acceleration enrichment strategy that injects additional fuel asynchronously (not timed to intake valve opening) combined with MAP prediction for faster transient response
Wideband heater profiles: How Bosch LSU 4.9 heater management works, differences between OEM and aftermarket controller implementations, cold-start heater ramp strategies

Hardware & Wiring

Sensor grounding: Why sensor ground (GNDA) must be separated from power ground (GND), star grounding topology, H7 board power requirements and voltage regulator considerations
epicTuner tips: MAP_PRE channel for predictive MAP visualization, YoloSync mode for quick trigger testing, ETB manual calibration fallback procedure

Weekly Digest: February 10–16, 2026

Highlights

[[../2026-02-12_tcu-a340-setup-guide.md|TCU A340 Setup Guide]] — Detailed Toyota A340 4-speed automatic transmission control setup

Technical Discussions

A340 TCU setup: Complete setup guide for Toyota A340 transmission control including solenoid wiring, gear state table configuration, range selector input, and TCC (torque converter clutch) PWM strategy
Builds on the earlier [[../2025-12-02_tcu-transmission-control.md|TCU overview]] with specific wiring and configuration details

Community

Continued general tuning support and firmware discussion throughout the week