JM8859-13,14,15

At &H1285 you have &HE0 (=7000 RPM).

On my JDM if I move this to &HF0 (=7500 RPM) I move the IPW step accordingly getting rid of a rich step where I'm making useful power and moving it to 106 RPM before the stock rev limiter, which I don't mind.

All the Evoscan datalogs that cross 7000 RPM on US Evo IX that I've seen (and also the VIIIs as well but I haven't disassembled those in this area to find the routines) show this step.

If you want to change it, have a play at your own risk and please post your before-after IPW vs RPM plots. Obviously make sure your AFR is OK - if you've already compensated your fuel map for this effect you'll probably want to flatten it. As previously mentioned, getting rid of the cause is better, because if you lean your 7000 RPM zone, you'll lean the 6500-6999 area by interpolation, which it doesn't need.

If this works as JDM it will improve the smoothness of your top end AFR curve and should maintain power from 7000-7500 a little better.

All the lean spool tables and code are there in the US ROMs as far as I can tell from disassembly. The values for the actual adjustments are similar too.

 

So, doing some quick digging in my '03 ECU (94170008), it seems like &H1685 might be the corresponding value. The nearby values look like this:

JM8859:
Row 1268: 0040 003D 0068 00E6 001A 000A 0006 0028 0028 0040 0010 005A 0050 0091 00E0 0080 00FF 00FF 00FF

94170008:
Row 166A: 003D 0068 00E6 001A 000A 0006 0067 0028 0040 0010 0075 0054 0091 00E0 0080 00FF 00FF 00FF 0017

I basically searched for "009100E00080" and that was the only hit I got in the '03 ROM...

Thoughts?

l8r)

 

I think that's the one to try. Not only because the data is so convincing, but because the subroutine that links to this location is identical to my JDM IX. In both ECUs this value is compared to a RAM value that appears to be RPM, and the preceding and following logic is identical.

I think you're safe to adjust it because it isn't a code section, so you shouldn't get any sort of crash or unprogrammable ECU.

 

I guess I'll put some more race gas in it ... just in case.

Any idea what the values around it are associated with?

Also, if:
&HE0 = 7000 RPM
&HF0 = 7500 RPM

then what is the equivalent of 8000 RPM?

l8r)

 

One more question:

Is this a uint8 or uint16 value?

l8r)

 

It is the generic 8 bit RPM scaling that is in lots of ECU maps. RPM=value*31.25
Max is therefore 255*31.25=7968.75 RPM (&HFF or decimal 255). Although the stored values in the map are words, I don't trust the code to do it properly, so keep any existing byte values to bytes to be safe.

 

Got it, thanks.

l8r)

 

I know what we are talking about, but unfortunately I am lost in the implementation.

 

This is the same exact location (1285) for this value on my 05 ROM, too, internal ID 96940011.


Eric

 

Don't have 9694, but I loaded 9693 and it seems to be fine at 1285, again links to the same routines.

 

JohnBradley, yours also is at 1285 on the ROM you previously sent to me.

The byte at 1285 is 224 (decimal). If you change to 240 (decimal) this changes the effect from 7000 to 7500 RPM.

In ECUflash:

Right click parameters and select new map. OK to inherit Evo9base.
Change type to 1D.
Put in a name like "IPW step". Put 1285 in the address. UINT8 in the scaling. Click Apply then OK.

Then file menu... save models.

Exit ECUflash and reopen and reload your ROM.
Then your new map should appear. Seems to go under misc even though I said to go under fuel. Then you can confirm the value is 224 and change it to 240.

Then reflash and test on Evoscan as you go through 7000 and 7500 RPM on full throttle. The IPW step upwards should have moved.

 

Thanks JC. Sometimes it comes easy to me, other times like this I need spoonfed...hehehe

 

Once I confirm that this works on my '03 ECU (94170008), I will post updated XML files.

I can also put together another "how-to" on adding map definitions to ECUflash... that way all the non-9417008 ECU owners won't be left out in the cold.

l8r)

 

Because I dont believe in pussyfooting, I reflashed with this value set at 254 and then went for a drive. I have my boost set rather high right now anyway (WG @ 112, Boost load at 145 curved to 159.4 by peak, 25-22psi) for pumpgas but I noticed an immediate improvement. I didnt log any knock increase in the 7000+ range, but I also hadnt ever tried to tune this out before. I have target AFR set at 9.4/9.5 and it seemed to love it.

Ludikraut-How to's would be really cool. As soon as JC explained it, it was a duh situation and I immediately added the definition like I had been doing it forever.

 

would appreciate this, since it seems i cannot add the map def on mine =/