I've never heard or seen a voltage reference table but there is an Evap Map 1 & 2 as well as a Cylinder Fuel Trim 1, 2, 3 & 4. I have no idea if anyone has tested if making changes on those tables will lean things out but assuming that the Evap Map 1 has some method of leaning things out when triggering Evap functions there is a possibility.

I'm wondering if all those maps were changed to 15.5 or 16.0 that it would shift the target values in closed loop.

 

in previous Evo's the ECU used a 0v ground to pass to the 02 sensor.

this ecu uses a 0.5v signal, so if you were at stoich you would get 1v back (assuming a 0.5v signal for stoich)

the ECU then subtracts the reference voltage and you end up with a normalised value..

so Gunzo's hypothesis is if you modify the subtractor then you can artificially change "stoich"..

but like i said this sort of feedback loop gives my brain lots of hurt

 

Well I do not think chnaging the reference 0v or the signal going from O2 could control the mixture. The signal is not linear (like with wideband), but changes quickly between 0 and 1V (a bit simplified). ECU leans when getting 1V and enriching when getting 0V (or negatively). This way it tries to keep stioch as average from a bit leaner and a bit richer.

 

yeh i know how it works I was just giving an example..

We wouldn't change the reference voltage, we would change what the ECU thinks is the reference voltage... ie the subtractor voltage..

I am happy to find it for anyone that has a WB and wants to test?

 

I know you know :-)

It would be great if the substracting in ECU worked. Unfortunatelly I do not have WB, so could not test the changes. Anyone´s help would be appreciated!

 

I can test.

 

Don't think the reference voltage is shared for the O2 .. its shared between the front and rear O2 though ..

You can also shift the 0% value for the idle fuel trim .. helpful especially if you have big lumpy cams ..

Alot of similiarities between our ECU and the Keihins

 

Tuning for fuel economy in an Evo seems a lot like those that try to use protection to last longer during sex...why bother?

 

Because I use the car for daily driving and while going 800km on highway the fuel economy is a metter.

Of course while enjoing the car on a curved road economy does not metter

 

5% of the $2000 I spent on fuel in the last year is still $100 free dollars in my pocket and a happier earth... but I'm one of those fools who runs a cat.

 

 

I wish we had as cheap gas as you in US!
I spend about 5k USD a year (12000 miles) on gas here....

 

Can we get the tables Richard?

 

Running e85 and driving a motorcycle that gets 44mpg helps... but foreign gas prices are definitely not an envy of mine!

 

Why risk expensive engine repairs for a few $$ in gas savings???? If you want good MPG buy a Festiva!!