Crome is a powerful tuning software for Honda ECUs, allowing for precise adjustments to fuel and ignition maps. This guide provides a step-by-step approach to Tuning With Crome, covering key settings, data logging, and analysis techniques.
Understanding Crome’s Basic Settings
Before diving into tuning, familiarize yourself with Crome Pro’s settings. Under the “General” tab in the “Settings” window, you’ll find “Selection Adjustments.” This crucial setting determines the increment for increasing or decreasing individual cell values when adjusting fuel maps. A 1% increment offers granular control, allowing for fine-tuning.
Setting Target Lambda (AFR)
Next, open the “Show Target Lambda” window (F10). This window defines your desired Air/Fuel Ratio (AFR). For example, you might target a stoichiometric AFR of 14.7:1 for lower RPMs (500-7936 RPM), transitioning to richer mixtures (around 13.6:1 in column 8 and 13.3:1 in columns 9 and 10) for higher RPMs and load. Remember, these are target values; achieving perfect alignment in every cell is unlikely. Aim for the closest possible match. Your specific values will vary based on your engine setup and modifications.
Note: Highlighted cells in the F10-F12 windows remain highlighted when you switch back to the “Ignition/Fuel Tables” (F9), ensuring seamless workflow.
Real-Time Tuning and Data Logging
With your target AFR set, begin adjusting the fuel map. Start with the idle range (500-1000 RPM, first four rows and columns 1-3). Use the Page Up key to richen the mixture and Page Down to lean it out. Observe the engine’s response and AFR gauge readings in real-time. Aim for an AFR around 15.3:1 at idle.
After initial adjustments, datalog while driving. A passenger can operate the laptop while you drive, ensuring safety and accurate data collection. Use the “Show Lambda Readings” (F11) window to monitor AFR during driving.
Analyzing Data and Refining the Tune
Analyze the logged data. Negative values in the “Show Lambda Readings” window indicate the need for richer mixtures, while positive values indicate the need to lean out the mixture. Instead of adjusting individual cells, modify entire columns for smoother transitions. For instance, if a column consistently runs rich, decrease values across the entire RPM range for that column by a calculated percentage based on the data.
Repeat the datalogging and adjustment process until your AFR consistently meets your target values across the RPM range. Utilize the 2D and 3D graph views to visualize the fuel map and ensure smooth transitions without abrupt changes.
Finalizing the Tune
After achieving a satisfactory tune, upload the changes to your Ostrich 2.0 emulator (or directly to the ECU if supported) to implement the modifications on your vehicle. Remember to perform final datalogging to verify the effectiveness of the changes. Tuning with Crome requires patience and meticulous attention to detail. This iterative process of data logging, analysis, and adjustment is crucial for achieving optimal engine performance and efficiency.
