Hi, may I ask how can u tell if the fueling map for my JDM EVO7 is leaner thant USDM EVO8? Looking at just the target a/f fueling table they look pretty convservative to me. Or does the differences in injector scaling have something to do with this? Sorry.. very noob at the moment

 

Take a look at these two maps:

Evo 7 high octane map


And here is the USDM Evo8 fuel map


Notice how your map has higher numbers (leaner) while the Evo8 map has lower numbers (richer) in the 180-240 WOT load cells. These cells are genrally lean on your map and rich on the Evo 8 map.

The reason fo this is that Mitsu is shipping JDM Evos to Thailand, but Thailand does not have the high quality octane gas that Japan has. IMO, Mitsu should ship cars to Thailand with a USDM map.

 

Hi

Mid term fuel trims are way off, do you have an induction kit? If not check of leaks after the MAF.

MB

 

Further notes,

I'm not sure how this effects the tunning but the MAF smoothing table on this evo 7 is very different than the USDM evo 8. The size of the maf is the same and the scaling tables are also the same but the smoothing table is much different. I wonder what higher numbers in the smoothing table do?

Secondly The boost table seems to indicate a very fast drop off in the boost to a point lower than the desired load in the Evo 8 is. I have my own settings for getting the turbo to 20psi and holding with a little taper.

 

I am using std induction box but with K&N drop-in. pardon for asking but what does mid term fuel trims do? does it get feedback from O2 sensor to adjust fueling for open loop?

 

Hi

Fuel trims are for closed loop fueling.

Boost is also limited by the upper restrictor near the BCS having an internal diameter of1.2mm Drilling this out to 2mm makes a nice boost increase, but you'll need to get the knock sorted first.

I used the USDM timing map as a base, for my JDM car in the UK, as I was getting knock on what is about 93 octane fuel on the US scale (98 RON here). Made for a nice safe starting point.

MB

 

Thank you. I think I'll be installing an EBC though just to make my life easier. Did you also use USDM fueling map or just timing? I want to try richen my car up a bit so the target a/f fueling map will be close to that of USDM, then try to put back some ign that I've retarded before.

If possible, can you share with me the map that u currently have? Thank you

 

I got somewhat bored so I made all the possible settings in the Rom file identical to the ones I use on my Evo 8 with California's 91 octane. I would only use this file for reference purposes.

Things Changed:

- High Octane Fuel map changed to my own map (on my car it see's 11.1 to 10.9 to redline in 3rd)
- High Octane timing map to match my own
- Open Loop 1 & 2 changed to look like and Evo 8
- Maf Smoothing Table changed to be identical to an Evo 8
- Open loop throttle (High & Low) changed to be identical to Evo 8 USDM
- Turbo Error correction higher values on the top and bottom
- Boost Offset Units to be identical to my car (Set my car to 20psi)
- Wastgate duty #2 set to a max of 127%
- Desired engine load #2 set to a straight 159.4
- Boost cut delay set to maximum possible time
- Speed limit set to really HIGH numbers
- Stationary Rev set from 5k to 5.5K


I am NOT an expert and this file should be THROUGHLY reviewed by experts before you even consider using it.

 

Giving this map a quick look, the only thing I really don't like is the boost cut is disabled, if it were me I'd use a value like 290, but you'd have to balance this against the load you get to, with 20 PSI 290 should be more than enough headroom. Also boost cut delay should be about 1000.

I just noticed the low octane fuel is about the same as the high octane fuel, should be altered for lower target AFRs.

MB

 

What if I plan to boost around 22psi? Would I need to do the "rescaling" of the MAF signals? or would 260 LoadCalc be enuf? Thank you

 

I relied on muchlower timing to take care of lower octane I figure I should probably lean my own fuel map out just a little bit so I'm more like 11.3 or 11.4 to redline.

 

The low octane fuel map is for when the ECU has detected to mush knock, usually over 6 counts, the ECU will interpolate between the high octane fuel and ignition and the low maps. Look at how much more retared there is in the low octane ignition map, the low octane fuel should have lower target AFRs then the high map.

MB

 

Ok I did that also set the Boost cut timer to 1000ms and the Boost limit at 290.

I believe this is what you specified yes?

 

Hi

That should be fine, it re-introduces a level of safety, as always though, built in ECU features are no replacement for good logging and tuning practices.

MB

 

OK guys... did some tuning today with AFR, these are the conditions

1. Std EVO7 engine
2. JDM EVO7 map with lower ign in loaded areas. Did it last week as it was pinging
3. K&N drop in filter
4. 3inch turbo collector + 3" downpipe + 3" cat-less tailback exhaust
5. Brand new Innovate LM-1 O2 sensor (heater and open air calibrated to read 20.9%)

This is the original map (BEFORE TUNING TODAY). AFR is very very lean for some reason?? Any comments pls??

I'll post my updated map in the next post.