ECMlink Target AFR maxoct table

[Kryndon]

This was the hardest thing for me to learn when I first started out with DSMLink no matter how much I tweaked my AFR maps the car did its own thing and then I learned under Closed Loop the AFR table is not referenced. However, on *most* late 90s and up Mitsubishis it's a fact that they are programmed out the factory to run north of stoich, so closed loop AFRs around 15.0-15.6 are very common. This was due to the drastic change towards lean burn adaptation, emissions standards and stuff like switching from the big/short intake runners on the 6 bolt to the longer narrower runners on a 7 bolt, promoting higher velocity and better air-fuel atomization. Others, such as Nissan, incorporated systems such as swirl jet valves just before the head inlets, to change the way the air mixes and flows into the chambers, also relying on a leaner mixture above 14.7.

I've nudged my closed loop just slightly above factory settings and on the highway doing 59-60 mph I get an easy 32 mpg. 2G manual AWD with 225/17 tires. One thing to remember is that higher combustion temps (due to leaner mixtures for example) promotes more torque and a more efficient burn; it's all about heat energy. And so long as you set the rest of your hardware right, the temp increase wont be a problem. In fact in one of your pics above, it says your coolant temp is 165F (73C) which is just TOO low for this kind of effect to really work. 90-95-97C is the general temp our Mitsus (and most others) like to run and have been engineered to run at. I've put a 1.1 bar rad cap on mine to help with this. But notice how your AFRatioEst is also quite high, up in the 16s. The ECU wants to pull fuel and run leaner so it would heat up to it's operating range but something (such as your thermostat) is getting in the way and making it run cold.

 

[steve]

Closed loop always will target 14.7 redardless what open loop maps are , and at ecmlink isnt an option to change that

You can change it, IF you're using a wideband to run narrowband simulation. You change the narrowband switchover voltage point which effectively changes the closed loop target afr

You can also just lock the ECU into open loop. Then the tune is all on you just like the old days.

 

[habitatguy187]

You can also just lock the ECU into open loop. Then the tune is all on you just like the old days.

I tried that recently and the car ran ok except for transitioning into and out of boost at light/mid throttle. It seemed to hesitate a little. Definitely could have been my tuning causing it, but I tried to clean it up and just couldn't.

......I'm thinking that it has to do with the feedback speed difference in the wideband and the ve table. During a pull the wideband lags behind the ve table, like watching a movie where the audio is off from the picture haha. And, it's fair to say that this is always the case when tuning the ve table, so idk