Hello I'm familliar with the evo world and what it offers in terms of tuning the stock ecu but it looks pretty wide open in terms of what you can do with it. I personally have a miata and was interested in fitting the evo 8 ecu to control my engine since they both use simillar crank\cam output setups and wastedspark coil packs.
I was looking on ebay and saw some evo 8 ecu's for sale for around 300 with key and something else,

http://www.ebay.com/itm/MITSUBISHI-L...5ad361&vxp=mtr

I figured that plus an engine harness and several key evo 8 parts that would be needed that I may not have.

A couple questions I have
Can you use a GM MAF sensor isntead of the stock evo maf or is the frequency output in a different area compared to the stock evo maf.

Can I take a stock ecu like that and flash it to program by just applying power to it and connect the proper wires needed for flashing?

Can the size of engine displacement for the maf tunign formula be changed from 2l displacement of the stock evo motor? Mine is a 1.6l turbo

Can you modify the obd2 codes it outputs currently, disable them or make them not flash the light?

Also I figure there is a fall back method incase the MAF goes bad, does the stock evo 8 ecu have this method tuneable?

Thanks for awnsering my questions I appericate it.

 

I don't have the all answers, but I think it's all doable, it would be like installing an aftermarket 'universal' ECU, it's what you do when a car's stock ecu isn't flash-able/tunable. Your main challenge would be connecting the Miata's harness to the correct evo ecu pins.
There is a MAF signal translator that allows you to install a GM MAF on an Evo or you could ditch MAF altogether & use a MAP sensor along with a speed density rom for the ECU, this might be more practical for your application!
You'd need to input the suitable injectors scaling numbers to fit the Miata's. You'd have to build the ignition & fuel tables from scratch to fit the 1.6 engine since the load/rpm curve would be different with a smaller engine.

 

I'm not to worried on the wiring part, the main issue I have is which tuning software out there should I look at using and can I to get access to the ecu like I linked to and flash it outside the car without most sensors connected.

Why would I need a mag signal translator, whats the difference between the gm and evo maf?

I'm not interested in running speed density as my upcoming setup will properly require either MAF or speed density that needs exhaust manifold pressure compenstation.

rebuilding the igintion table shouldn't be hard, though I question why I would need to build fuel tables exactly for if the stock ecu is maf based, unless you meant for a SD tune. pther then the injector scaling number is there a scalling figure for displacement as well?

Thanks for the info

sorry if I posted it in teh wrong area, ecuflash looked good so far from going over it.

 

Ecuflash is the software to use for flashing the ecu, (openecu.org). You would need an openport 1.3 connector (Tactrix.com) the Evoscan software is used for data logging, it can be purchased at evoscan.com. You could use the evo MAF sensor, you still have to adjust the fuel table for open loop fueling.

 

There's no displacement parameter in the Evo ecu, there's also little to no need for the key. You can disable the immobilizer.

 

there is something related to displacement in the formula the ecu uses to compute load based off maf. But if its not currently user editable then it seems I will have to pass using the ecu until the parameter becomes user editable.
1.6l vs 2l is a good enough displacement change to show up.

 

Never heard of such thing, not with an Evo ECU at least! It's all about the load/rpm curve, different displacement engines would have different curve that you would need to accommodate in both ignition & fuel tables.
Bear in mind that many Evo are storkered & have larger displacement engines (2.3-2.6) & still tuned with the same ECU. I once used an E8 ECU on a 4G93 1.8L engine & tuned it.

 

First step would be to read up on the tephra modded roms. Then get a tehpra base map and open it in ecuflash and get familiar with everything that is there. It will be quite the learning curve at first. This displacement issue is really a non-issue. I wouldnt worry about a GM MAF, i would run the stocker at first, and probably a set of stock injectors. Then just dial things in from there. Your biggest hurdle will be fabbing up the proper piece for the cam/crank signal.

Rescale the load axis in the table for your setup and let it eat.

 

How do you think load is dervied? Its from 100% VE of a engine vs actual VE of an engine. If you can't change the displacement being used for the formula of deriving load then you start getting skewed load's which can effect other items that require the use of load in the ecu.

The curve maybe different due to a different design of motor but generally its not gonna go over 100% load unless its a highly tuned out engine or forced induction is used.

 

Is your Miata still naturally aspirated? If that's the case then load won't exceed 100% & it might be easier to use an NA rom image to tune the ECU. Otherwise, with an Evo's rom, you could recscale the load axis to max of 100% in both fuel & ignition tables, start with a smooth conservative ignition table, & tune fuel first until you reach desired AFR & then you would tune ignition table.
The data logging software would indicate what load value your car is hitting at a certain rpm, each such point load/rpm needs an optimal ignition & fuel values & that what needs to be inserted during the tuning process.

 

turbocharged

do you have more info on rescaling of the load axis?

 

I would not worry about the "displacement scalar" you're inquiring about.

Why not just use the evo maf, or do speed density(best option here...works excellent)?

So long as you can get the electrical and signal logistics sorted out the tuning of it would be pie.

Best starting point : https://www.evolutionm.net/forums/ec...ead-links.html

 

Turbocharged, then your engine will exceed 100% load, what type of turbo & what boost level?
Rescaling load is done by simply inserting different values, it's usually done to accommodate higher than stock boost levels and turbo upgrades, it could used the other way around, decreasing max load & giving you more resolution in both ignition & fuel.
It's still the same process, data logging should provide you with the load vs rpm coordinate to build both ignition & fuel maps.
The image is of a stock ignition table vs rescaled load table