This forum is concerned with tuning. As a lot is known about tuning for power for now (where you can also easily damage the engine), why not discuss tuning for better mileage???

 

what are the Cylinder Fuel trims table doing ? In closed loop the reference afr will be that ?

 

from what i percieve 14.7 is a base, not a target...
add to it and lean it out, take away and it gets richer
however this only works in open loop...

ive tested this to an extent and it helped rid me of knock at high rpm...

also its a battle to get good economy with this gearing, unless you drive no faster than 65mph or put the car on a diet so it takes less ponies to move it, lol

 

That´s right! I can make the car having good mileage while driving up to 60-65 mph. Unfortunatelly we have speed limit 81 mph and no limit in nearby Germany :-), and I found it not to be possible to get good mileage at higher speeds with lean AFR. Seems like the air resistance is so big that leaning out makes no difference in mileage.

 

of course, there is a limit where the drag will ruin economy...

for the evo ix that limit was about 90km/h - any higher than that and eco went down...

 

the base of what ? Is there any case in open loop when the ecu look in that table instead of the high oct fuel maps ?

 

To keep it simply, you can make an ecconomy map that has lower load request and 0 wgdc limits below 50% throttle and 4k rpm. You can also add 3 degrees of timing in those same rpm ranges between 50 and 80 load, where the car is spending most of its time cruising. These changes will be good for a couple of mpg.
Beyond that, your right foot controls your fuel ecconomy.

 

I also think that MIVEC tuning could be a big key in economy. The problem is that it's very hard to tell if your changes made a difference. I'm really looking forward to Tephra's Live Tuning so that I can tune my MIVEC for econ.

 

If u have a wideband that has a narrowband switching point might work just like on the 8 & 9s. Dont know the ecu pin to use for this.

 

Yes, it works. I have moved my cruse lambda from 1.0 to 1.09 (best fuel economy) and the mileage is much better. You just connect the WB simulation output to the NB signal input.
But EVO X uses 0.5V offset for lambda sensor, so that lambda signal does not jump between 0.1 a. 1.1V, but between 0.6 and 1.6V instead. These are simulation voltages you have to set at WB. Otherwise you will look at the STFTs maxxed out, engine hesitating and wondering WTF is going on - like I did...

 

Great info! thanks!

Any numbers on your improved mileage?

 

I get now 25 mpg while calm weekend trip diving

Before the best I could get was 20-21 mpg. Of course you cannot do WOT overdriving, otherwise all mileage goes to ***

 

One more thing that could help more is zeroing both WGDC tables, but I want to have one map which is economic in cruise and gives me power under boost.

 

i see so the simulation voltage needs to be altered to make it work. with zeitronix i don't think you can alter the simulation voltages

 

I do not know about Zeitronix, but LC-1 allows it.