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vimsh edited this page Apr 12, 2021 · 22 revisions

http://vimsh.github.io/mafscaling/

Mafscaling

is a program which helps to tune Subaru cars by processing and analyzing ECU logs. It was initially written for MAF scaling (thus the name) and then it was extended to provide more tools.

Note:    In order to load the log file please make sure that file doesn't have any extra information at the top and actually starts with column headers

At the moment the following tabs are available:

  1. Open Loop - used for open loop MAF (Mass Air Flow) scaling based on WOT (Wide Open Throttle) pulls. You would use it whenever you install upgrades that change Air/Fuel ratio, eg CAI (Cold Air Intake), larger injectors.

  2. Closed Loop - used for closed loop MAF scaling. Same as Open Loop you would use it whenever you install upgrades that change Air/Fuel ratio, eg CAI (Cold Air Intake), larger injectors.

  3. MAF OL/CL Merge - used for merging and fitting open loop / closed loop MAF scalings. When a MAF OL scaling and CL scaling is done from the same log this tool should help to merge both scalings while also applying fitting algorithm to smooth the curve.

  4. MAF Rescale - used for custom MAF reallocation of existing curve points. Sometimes after adding modifications and rescaling (Open/Closed loop) the MAF table you may find out that some of the points at low MAF voltage scale are never hit (at idle your log shows MAFv values which are closer to 3rd or 4th point of MAF scaling), and some other times you may find that the points at high MAF voltage scale are never hit (at WOT redline cutoff you log shows MAFv values closer to some point which has 3-4 more points after it). Those "unused" points could be reallocated to the mid-upper effective range to improving the accuracy of Air/Fuel calculation of closed/open loop transitional and open loop area of MAF curve.

  5. Table Rescale - used for rescaling of existing 2D/3D table header values. Two interpolation methods are provided - Linear and CusbicSpline for 2D tables; BiLinear and BiCubicSpline for 3D tables. The extrapolation, although is prone to error, is also doable for 2D tables, whereas for 3D tables the extrapolation is done as 2D for each row if column header value was changed or each column if row header value was changed.

  6. Throttle Maps - used to generate throttle plate versus accelerator pedal table where x-axis is accelerator pedal angle (%), y-axis is engine speed (RPM), and values are target throttle plate opening angle (%), which should help in making changes to any of the base tables.

  7. Load Comp / Injector Pulse Width Compensation - used to adjust Load Compensation or Injector Pulse Width Compensation tables to improve fueling calculation based on engine RPM and Manifold Pressure for Load or Injector Pulse Width for PW.

  8. MAF IAT Comp - used to adust Intake Air Temperature Compensation table to improve fueling calculation based on IAT temperature and Mass Air Flow.

  9. MAF VE Calc - used to build Speed Density map based on your existing well working MAF scale (MAF Builder) or to fine-tune existing SD table (AFR Tuner). Use MAF Builder when switching to Speed Density you could run your car in MAF/SD mode (unless you've removed your MAF sensor already) and build SD table based on MAF scaling. Use AFR Tuner to make adjustment to the SD map based on AFR (Air/Fuel ratio) error (you would have to select Open Loop or Closed loop when loading log file).

  10. WOT Best VVT - used to analyze VTT angles by best volumetric efficiency. Logged VVT angles are compared to volumetric efficiency of each WOT pull allowing changes to be made to VVT systems and compared for the best settings. The logged VVT with the best VE will be the ideal VVT setting.

  11. Log Stats - used to analyse ECU log by calculating statistics (on specified Data column of a log file) over specified X/Y axes (specified as any column of a log file). The axes values can be specified as a step or fixed axes. The stats will be calculated on Data column after all filters (if specified) are applied to the log file data. The result data is presented as a table and 3D plot.

  12. Log View - used to display log data in a table and as 2D and 3D plots and map tracing. A single filter can be applied to the data to be displayed. The tool also allows to set markers for desired area and replay the log data over specified tables (map tracing). While replaying, the tool allows to mark the cells which are used for current value calculation, mark the most significant cell, show current value by placing dot over the tables cells, trace the current value change as a line.

Please always check Usage Tab for the tool you're planning to use.

DISCLAIMER: This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

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