Currently building a DD car, I installed an Evo 7 engine without a turbo on a Mirage, I changed the stock pistons with NA high compression ratio pistons, paired the engine with an Evo 7 GT-A automatic transmission. So, I'll be using the Evo 7 GT-A ECU, harness, MAF, injectors. I plan to tune the ECU & trying to figure out what changes should I apply since the car is NA now, changes like closed loop, AFR...etc. I'd appreciate any tips & advice.

 

Interesting project. There is really not much to it but the biggest change would be the need to tune the ignition timing.
If you think about it, the only difference as you say is the turbo and the higher compression ratio.

In a normal evo, what would happen if the turbo is taken out of the equation of the engine management?
In both MAF and MAP referenced load calculation, they would not hit the higher load cells. Same here in this scenario.

Then in reference to the airflow, you would need to adjust timing to suit your engine for MBT without knock.

For closed loop fueling it is going still to be targeting stoich.

You can rescale your load reference since they won't go higher than a certain value now that you are NA.

 

yup i agree

 

Yes, it won't hit higher than 100 load, as for timing, the plan is to keep it close to the stock numbers providing there is no knock since the timing numbers under 100 load are decently high. The tricky part might be fueling as I'd need to lower AFR to around 12.1 at high RPM & I'm not sure if I need to alter the closed loop settings so I could have enough control to make changes under the vacuum part of the table.

 

What compression ratio are you using? I think you might find that you need to reduce timing on the GTA map. I ran a 10.5:1 N/A engine in my Evo 1 (still with the turbo) and it used to detonate in the vacuum areas of the MAP (as well as under boost of course). I had to remove quite a lot of timing, It was a long time ago, but I recall as much as 10 degrees in some areas.

I would probably tune it in open loop, see what AFRs it likes for the different load/rpm ranges and then se your clsoed loop parameters based on where you have 14.7 or thereabouts in your map.

 

The CR is around 12.5:1 reducing the timing is no big deal, my main concern is the fuel. I'd want to maintain CL since it's a DD car, but I still want it to switch to OL at higher RPM so I could enrich AFR to around 12. The default (turbo) settings are meant to have OL kick in above 100 load, so I'm guessing that I need to alter OL settings so it kicks in around 70 load/ 70% tps, that could be a good starting point!

 

Hope these help...

Both are 4G63 NA maps.

1) RVR N23W NA stock fuel and timing maps below:



2) Galant E33A AMG stock fuel and timing maps below:

 

Yes indeed, they are very helpful, thanks Allan

 

Any idea about the closed loop/ open loop settings in those roms?

 

how are these tables termed in terms of evo8/tephramod xmls?

 

 

this is what i have for the RVR NA...

i presented in hex to avoid conversion/formula errors with decimal values...

not sure if this is what you need, though...