How exactly does the blm tables work? I know I've read alot about how the magic number for the blms are 128, why is that exactly? Is the 128 BLM like the Lambda=1 referance when tuning with a wideband o2? I've tuned a few different vehicles using tunerpro and tunerpro v5 and am curious about how the blm table actually functions...

Thanks,

 

Lambda +1.00 is stoich . All fuel is being consumed. A/F is spot on. 14.3 for E10 and 14.7 for reg gas E85 I think is 9.+

BLM is the block learn mode.

02 feedback moves the integrator(128 + -). Short term change.

After INT moves it may trigger a long term BLM (128+ -) change arriving at stoich.

BLM is affected by environmental temps and mechanical changes in engine.

see stickies above...

 

ok i read up on the blm tables and now understand how they work, now my next question is how would I change the afr that it's trying itself to correct to read a different afr rather than 14.7? I'm going to be running an 8625 pcm in pfi mode using the 0$ maf code so I'm trying to learn as much as I possibly can before i get my engine together.

 

not sure about your def file but mine has a constant called "stoich". It is set stock at 14.7. I reset mine to 14.3. I believe 14.3 is richer than stoich EVEN though I run E10.

Also 02 swing points rich/lean median. I moved them higher by 10% .

 

There's hardly any 'bandwidth' to play with using a nbo2. The switchpoint is between roughly 14.9 and 14.5. Check this out.

 

Easiest thing to know about BLM is you want them hovering very close to 128 in all conditions. Getting exactly 128 is nearly impossible. Some of the best tuners can hardly do it.

 

that is why my calibrated WB shows 14.5-1 14.9 at cruise. DE and DFCO is disabled.