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I was hoping for a phone app or maybe even a tablet program to make changes on the go a bit easier. Maybe even some gauges to look at when logging instead of the tiny table of figures? Bit hard to see when driving ;p
 

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G'day gents, LYH45 asked in his build thread: 'In regards to the disable o2 sensor mentioned is HateCrew's post is that for closed loop? What exactly does that do?"

This is my reply, please let me know if any of this is not accurate. This info is only for our Aussie EJ251's with only 1 narrowband sensor in the exhaust. PLUS we are both about to start tuning turbo'd NA engines using a standalone AEM wideband sensor.

IF this explanation is way off, i'll happily delete the post so as to not send anyone down the wrong path! We don't have many things to adjust in our ECU's (idle, throttle tip-in aside) so I can't see what else would really affect the amount of fuel used for a given situation (we can't adjust anything for intake air temps, only coolant).

Disabling the O2 sensor and forcing open loop helps you dial in the VE table for cruising and light load (basically 14.7:1 AFR) and to suit the Power mode fuel ratio target lambda values which you'll also need to set first (plus the throttle enable %).

Once doing some runs (at full operating temp) at various but STEADY STATE rpm and map kpa's, AND watching/logging the wideband sensor, you'll be able to adjust the VE to achieve 14.7:1 or the power mode fuel ratio target. I believe this will also get your fuel trims sorted.

For getting the tuning right for high load & rpm's, my plan is to disable the O2 sensor, find a long big hill in the middle of nowhere. Do some runs and datalog at various (steady) rpm and map kpa's (light/medium load first, then on the power mode target). I'd suggest having someone to help watch (and listen) for knock correction while running.

When I'm fairly happy with the VE and wideband AFR's - do some long runs at full load, shut the engine off while (under load & rpm) and roll to a stop. Pull out the spark plugs to check them, they will always be what tell's you how much fuel and spark timing the engine wants. Tough part is knowing what to look for on the plugs! I know SOME of it, but the old man knows it all and I'll definitely need his help!

Even before looking at the plugs I'd still be checking every run's datalog, looking for knock corrections (though not fully rely on this in the end, always check the plugs) or try to listen with a headphone setup attached to the block.
 
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