The Open Import Fuel Tuner is a very flexible and open-ended project, as anyone may take
the development effort presented here and continue with any design modifications possible.
However in the interest of completing a respectable portion of this project anytime soon,
we have developed a list of initial functional goals.
O.I.F.T Initial Functional Goals:
- Unlimited MAP sensor translation. By using a
configurable piecewise linear MAP sensor re-mapping function, it should be possible to
precisely control fuel management by only upgrading the fuel injectors. By using the
stock Fuel Pressure Regulator and stock fuel pressures we will increase the design
simplicity, reliability, and improve driveability.
- RPM-based fuel adjustment for tuning, similar to
the VAFC but with more RPM points.
- IAT translation - modifying the IAT signal for
certain conditions. This could be used to emulate a JR MAP controller for a 6psi kit with
stock injectors and the JR FPR. Once the user upgraded to larger injectors, the MAP
translation function could be updated to allow smooth idle and sufficient top-end fuel.
The JR FPR would also be removed.
- TPS translation - modifying the TPS signal for
certain conditions. This could be used to force the ECU into open-loop mode during
positive manifold pressure (boost) conditions.
- Data dump - For rigorous tuning, it will be
necessary to transmit high-resolution, high-frequency data for logging and analysis.
The following signals should be digitally delivered across a high baud rate serial
connection:
- Spark Timing Advance
- MAF / MAP Sensor Level
- Throttle Position
- Intake Temperature
- Oxygen Sensor Level
Once these goals have been realized, we will turn to the 'wish list' of extra goals
which will provide extra functionality and advantages for owners of modified Import
cars.
O.I.F.T Extra Functional Goals:
- Spark Timing translation. A boost-dependent
timing retard function may be created to emulate a Jackson Racing Boost Timing
Controller. RPM-based adjustments are also possible, to remove the ECU's timing
retard at the VTEC engagement point and intake runner switching point.
- Knock Sensor Processing.
Texas Instruments has an excellent article covering
several signal processing approaches for analyzing knock sensor data, which is
available here.
The methods described in this application note may be used to provide a knock detection
function for use in datalogging. A good amount of statistical analysis of the knock
sensor and engine characteristics must be completed before this goal can be realized.
- Wideband O2 Sensor Interface. The possibilities
of this are endless. Ultra-smooth and responsive tuning would certaintly be possible.
Even some mad-science iterative self-tuning function is not completely outside of the
realm of possibility. Imagine watching the HP curve go up over successive dyno runs
as the controller learns the optimum tuning.
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