Spent a little time reading about the SD tuning for E38 ECMs, and wow, what a mindfuck. The days of simple VE tables are gone. GM uses something called zone mapping coefficients that determine how much fuel to deliver to the engine. But the only way to get these coefficients is to use a number cruncher program called MATLAB, or another 3rd party program called EQ VE3, which is equally confusing.

I know its a long shot to ask, but has anybody had experience with this yet? If ever there was a dark art of tuning, this is it.

 

I have done SD tuning with the newer PCMs that employ the coefficients system. The EQ VE 3.5 which is the newest version if I remember correctly I think is very simple to use.

Just have the tune you are working with and the program open at the same time, open all of the coefficient tables in the tune that it requires, copy coefficients into the program, it spits out the VE table in the program. Log plotting lambda/AFR error against VE, make changes to the VE table in the program based on the AFR error you logged and then generate equations, send equations back to Hptuners tune file with all of same coefficients tables open and their will be the changes. As with any airflow mapping repeat until error is within 1%-2%.

 

Awesome man, thanks. I'll give that a shot and post up my results.

 

Every time some new way comes out, it seems more confusing, but it gets better with time. Klug's SS, thats good info. Thanks from all us learning.

 

Is it possible to tune ve on E38 pcm's without a wideband?

 

Just as on LS1's while it can be done how accurate it will be is the question. Always better with a wideband.