Holley EFI Parser

Python toolkit for parsing Holley EFI data - including binary data logs (.DL/.DLZ) and real-time CAN bus communication.

Features

• DLZ Decompression: Decompress DLZ files with 100% accuracy
• Multi-Format DL Parsing: Parse V3, V4, V5, and V6 Holley DL formats
• Real-Time CAN Bus: Live dashboard for monitoring ECU data via CAN bus
• Batch Analysis: Process multiple log files with comprehensive statistics
• CSV Export: Convert binary logs to CSV for analysis

Project Structure

holley-efi-parser/
├── holley_parser/          # Binary datalog parsing
│   ├── dlz_decompressor.py     # DLZ → DL decompression (100% accurate)
│   ├── universal_dl_parser.py  # Main DL parser (V3/V5/V6 support)
│   ├── batch_dl_analyzer.py    # Batch file analysis
│   ├── dl_analyzer.py          # Raw hex analysis tool
│   ├── comprehensive_dl_mapper.py  # CSV-to-DL mapping tool
│   └── csv_dl_comparator.py    # CSV comparison tool
│
└── can/                    # Real-time CAN bus tools
    ├── holley_can_parser.py    # CAN message parser & live dashboard
    ├── holley_config.yaml      # Configuration template
    ├── *.dbc                   # Holley DBC files for decoding
    └── README.md               # CAN-specific documentation

Installation

git clone https://github.com/HackingLZ/holley-efi-parser.git
cd holley-efi-parser
pip install -e .

For CAN bus support:

pip install -r can/requirements.txt

---

holley_parser - Binary Datalog Tools

DLZ Decompressor

Converts compressed .DLZ files to .DL format with 100% accuracy.

from holley_parser import decompress_dlz, decompress_file

# Decompress in memory
with open('mylog.DLZ', 'rb') as f:
    dl_data = decompress_dlz(f.read())

# Or decompress to file
decompress_file('mylog.DLZ', 'mylog.dl')

Algorithm:

1. Byte swap (endian conversion)
2. RLE decompress (0xFF COUNT VALUE)
3. Byte swap result

Universal DL Parser

Parses decompressed .DL files into pandas DataFrames.

from holley_parser import UniversalDLParser

parser = UniversalDLParser('mylog.dl')
df = parser.parse()

print(f"Parsed {len(df)} rows x {len(df.columns)} columns")
print(f"RPM range: {df['Param_002'].min():.0f} - {df['Param_002'].max():.0f}")

Supported Formats:

Format	Magic	field_08	Status
V3 (Terminator X)	0x0095365F	2-3	Supported
V4	0x0085F41F	4	Partial
V5	0x0085F41F	5	Requires Holley conversion to V6
V6	0x0085F41F	6	Fully supported

Full Pipeline Example

from holley_parser import decompress_dlz, UniversalDLParser
import tempfile

# DLZ → decompress → parse (works for V6 DLZ files)
with open('mylog.DLZ', 'rb') as f:
    dl_data = decompress_dlz(f.read())

with tempfile.NamedTemporaryFile(suffix='.dl', delete=False) as f:
    f.write(dl_data)
    temp_path = f.name

parser = UniversalDLParser(temp_path)
df = parser.parse()
df.to_csv('mylog.csv', index=False)

Other Tools

Tool	Purpose
batch_dl_analyzer.py	Analyze multiple DL files, identify format variations
dl_analyzer.py	Raw hex analysis for debugging
comprehensive_dl_mapper.py	Map CSV columns to DL binary offsets
csv_dl_comparator.py	Compare CSV exports with DL binary files

---

can/ - Real-Time CAN Bus Tools

Real-time monitoring of Holley ECU data via CAN bus with live dashboard, DBC decoding, and ECU serial filtering.

Quick Start

cd can/

# Live dashboard on CAN interface
./holley_can_parser.py --interface can0 --ecu-serial 19838 \
    --dbc "HP Dominator & Terminator X DBC.dbc" --live

# With min/max tracking and recording
./holley_can_parser.py -i can0 -e 19838 \
    -d "HP Dominator & Terminator X DBC.dbc" \
    --live --minmax --record session.log

Features

• Direct CAN Interface: Listen on can0/can1 without candump
• Live Dashboard: Real-time sensor display with color-coded safety thresholds
• ECU Serial Filtering: Filter by ECU serial number for multi-ECU setups
• DBC Decoding: Automatic message decoding using Holley DBC files
• Multiple Outputs: Human-readable, JSON, CSV formats
• Safety Alerts: Configurable thresholds (RPM, oil pressure, coolant temp, etc.)

Included DBC Files

File	Use With
HP Dominator & Terminator X DBC.dbc	HP/Dominator (V4+), Terminator X
HARDWIRE HOLLEY DBC FILE.dbc	Alternative format

CAN Interface Setup (Linux)

sudo ip link set can0 type can bitrate 1000000
sudo ip link set up can0

# Start monitoring
./holley_can_parser.py -i can0 -e YOUR_ECU_SERIAL \
    -d "HP Dominator & Terminator X DBC.dbc" --live

See can/README.md for full documentation.

---

DL File Format Notes

V5 vs V6 Format

• V5: Sparse storage format used by ECU. Cannot be parsed directly.
• V6: Full format created when V5 files are opened in Holley software.

Workflow for V5 files:

1. Decompress DLZ → DL (our tool)
2. Open DL in Holley EFI software (converts V5 → V6)
3. Parse V6 file (our tool)

V6 DLZ files (newer ECUs) work end-to-end without Holley software.

Key Parameters

Column	Parameter
Param_000	Point Number
Param_001	RTC (timestamp)
Param_002	RPM
Param_066	TPS
...	(516 total parameters)

---

Development Status

Component	Status
DLZ Decompression	100% accurate (verified against 9 file pairs)
V6 DL Parsing	Working
V5 DL Parsing	Requires Holley software conversion
V3 DL Parsing	Working
CAN Bus Parser	Working

---

License

MIT License - See LICENSE file for details.

Disclaimer

This is an independent implementation not affiliated with Holley Performance Products. Use at your own risk.

Contributing

Contributions welcome! Areas for improvement:

• V5 format direct parsing
• V4 format support
• Additional parameter mapping
• Unit tests