Tuning
Basic Concepts of Honda Engine Management
An introductory guide to electronic engine management concepts for Honda enthusiasts, covering air, fuel, spark, and sen...
Data Link Connector (DLC) Communication Protocols
Technical specifications of the Honda OBD1 Data Link Connector (DLC) communication protocol, voltage levels, capacitance...
DIY Dual-ROM Setup (27C512 Jumper Switch)
Hardware modification guide to creating a dual-ROM setup using a 27C512 EPROM and a toggle switch to select between two...
Exhaust Gas Temp Sensor
The exhaust gas temperature (EGT) sensor and what it tells you.
Full-Duplex Datalogging & the `J12` Jumper
Explains the difference between half-duplex and full-duplex serial communication on OBD1 Honda ECUs and why removing the...
Honda ECU Serial Datalogging (`CN2` TTL Header)
Learn how Honda OBD1 ECUs communicate with tuning laptops via serial TTL signals (CN2 header), including pinouts, settin...
JDM P30 D12 analog-input modification
Archived JDM P30 D12 circuit modification for logging a 0-5 V analog input through the ECU.
Logging an external 0-5 V sensor through P30 D12
Archived USDM P30 D12 analog-input method for logging an external 0-5 V sensor.
Logic Mapping & Truth Tables for EPROM Emulation (RTP)
Technical logic tables, address line mapping, and boolean gate reductions for building custom Real-Time Programming (RTP...
Proposed Datalogging & RTP Protocol
Technical specification of the proposed high-speed, stream-based custom datalogging and Real-Time Programming (RTP) prot...
USB-to-TTL Serial Converter Guide (`FTDI` & CP2102)
How to configure and troubleshoot USB-to-TTL serial converters (such as FTDI or CP2102 chips) for reliable ECU dataloggi...