Can anyone explain what is Arbitrary MAP Spacing? How it is used? Its under tuning modes in WARI. Think it's used in Eugene too.

 

I am under the impression that it means you can have increments of 100 down low and then have rpm increments of 500 everywhere else. That way, the areas that need to most fidelity between rpm points can have it, whereas the points that have very little need for close spacing can go without it.

 

That's exactly what it does. It allows you to specify the exact RPM and MAP value of each cell of the fuel and ignition table table. However, I found that with the 440d, auto tuning does not work with arbitrary spacing. It will only update the first row of data. If you don't care about rapid learning and slow converge, by all means play with the arbitrary spacing. I gave up on it, wasn't worth the bugs and I'm not sure closed loop was working correct either. It could have just been a 440d select issue though. Wouldn't surprise me if it's fixed in the Modular ECUs.