Features Requests regarding Alpha-N setups | AEM
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Mafiozos
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Joined: 02/07/2015 - 15:12
Features Requests regarding Alpha-N setups

Hi, i am new in this forum... so i don't know if there is already a thread for this. I have an s2000 '01 ems2.I wanted to change the strategy to drive fuel and ignition tables to the Alpha-N method but i found it lacking some features to fully support this option. Let me start by saying that i am aware that there is always the hybrid option to use the Alpha-N algorithm but has the same fundamental problems relating to slow response as the speed density algorithm although at a dimished magnitude (ofcourse there is also the accel enrichment setting). If someone would like to run solely on Alpha-N algorithm (no hybrid) he will face some problems regarding the everyday operation of the vehicle. First and foremost, IAC valve and idle control. Using the Alpha-N algorithm the driving force of fuel and ignition tables is TPSposition and EngineRPM. Therefore while you have setup your idle perfectly when the FAN/AC/LIGHTS kick in the value at the fuel/spark table remains the same. As a result the same amount of fuel will be deliverd and the same amount of ignition will be used. The increase in work effort will reduce engine RPM (same fuel=same power) to even stalling it. Ofcourse to prevent that you will have to use FUEL vs Idle RPM and IGN vs Idle RPM... but those tables only work when there is an error in the target idle rpm... you will always experience the Droop of the controller... wich means that it will never reach the idle target rpm and always run at lower RPMs than your normal idle. Because of the Droop the IAC will constantly try to increase the amount of air entering the engine to no avail (since the cell at fuel table does not change) making the combustion leaner losing even more power. Long story short, there needs to be a mechanism by which when in idle to use hybrid mode (taking into consideration MAP) or maybe a 2x2 or 3x3 table for idle fuel encrichment driven by IACposition vs RPM (like a separate throttle body), or maybe something else. Secondary, when you get off the idle opertaion the IAC can skew your AFR's cause it will allow more/less air to enter the engine depending on it's last position. So maybe a IAC running position setting is required in order to fix the IAC in a known position when the engine is not idling. At the current state the Alpha-N algorithm for everyday use is unfavorable. It would be nice if you could do something about these issues. Thank you in advance.