Hondata Engine Maganagement System - Dyno Cell

Fuel mapping is consistent with OEM size as far as resolution is concerned, but the major advantage is the Hondata's ability to compensate for fuel tuning under boost. In normally aspirated trim, the map has a total of 200 cells for the low-speed map and an additional 200 for a high-speed map. The low-speed map is designed with a 10x20 format. The high-speed map is also set up as a 10x20 with rpm starting at 3500 rpm. There are 10 columns designated for atmospheric pressure and 20 rows for rpm. The unit can measure vacuum in millibar (mbar), kilopascal (kPa) and inches. For a boosted application, the tuner has the choice to view pressure in millibar, kilopascal, bar (bar), kilograms per square centimeter (kg/cm2) and pounds per square inch (psi). In a boosted application, rather than taking away resolution from vacuum to compensate for the added boost adjustments, the Hondata unit will add an additional 60 cells (3x20) to compensate for up to 11 psi of boost pressure. If boost pressure exceeds 11 psi, the user also has the ability to add an additional 60 cells expanding boost resolution to 6x20 (120 cells). Hondata offers a three bar replacement sensor to make use of the additional boost, since the factory MAP sensor can only calibrate up to 12 psi. Tuning adjustments are executed in plus or minus one percent increments. The software also allows for group changes. Rather than change each cell one by one, the tuner has the ability to highlight a region of the map and make a percentage change throughout the entire highlighted area. There are plans for the software to be upgraded with map tracing. In doing so, changes can be made to the most affected area of the map.

Timing maps work in the same way as the fuel tables, but cell numbers are actual timing degrees for the specific rpm/cm Hg. The Hondata unit can make timing changes in quarter to full degree increments. Mapping sizes are identical to fuel tables only the data is shown in timing degrees.

With 20 available rows of rpm and 10 columns of vacuum, resolution can be lost in between rpm and vacuum. An example would be how you can adjust rpm at the 4000 rpm point and the next row down would be 4500. What the Honda ECU does is interpolate between these to points by taking an average of the four surrounding cells to come up with a smooth transition between the rows of rpm and columns of vacuum. Since there is a big jump between both rpm and the measurement of vacuum the software will figure out the correct compensation.

The Hondata unit also allows for injector and fuel pressure changes. If a user has programmed a unit to control 240cc injectors, yet they have upped the size of the injectors, the user has the ability to compensate for the difference in size. Of course, fine-tuning has its benefits, but this compensation allows the tuner to cut down tuning time. The ROMEditor software is also capable of changing fuel mapping, if fuel pressure changes, by punching in the before and after pressure changes.