I am at the point where this might just be pertinent. I finally got started with the VE tuning tonight. WinALDL spit out tables with BLM, INT, Spark Counts and all sorts of other stuff. I started tuning with the Wide Avg BLM and INT tables that WinALDL produces as text files. A little magic with Excel and I have an instant tuner system...kinda. I think it works about like VEPhD works for the TPI cars, but I could be wrong. I'll find out this weekend when I REALLY spend some time with it.
Anyway, I noticed the idle moving around in a block of BLM values and I was wondering what these "BLM cells" I keep hearing about are. What do they mean in the "big picture"?
TIA...

 

Ill take a stab at it...

Basically, there is a 4x4 table in the ecms memory with the boundries defined by rpm and map. Each loaction is termed as a cell and there are 16 cells. Each cell is used basically as sort of a post-it note for the ecm so it knows what the blm was when it was last operating in that cell. This way, the ecm wont have to relearn everything over again. The blm itself is used to trim the fuel. The ecm divides the blm value by 128 and then multiplies the BPW by it to adjust the fueling.

 

Okay, that's simple enough. If that's where the BLM comes into play, what does the INTegrator do? I just finished making up a new VE1 table using the BLM and INT calculation. (BLM*INT)/(128^2) is the one I used. I haven't run it yet, but it will be tested today.

 

I modified my BLM RPM boundries by taking the stock values and adding 400 (I think that was the #). The lowest RPM boundry was un-atainable with my new engine, so I incremented the values accordingly, and I also scaled my MAP boundries to values that matched what the new engine ran with. After making the changes, I noticed a smoother idle, and my BLM Cell value was changing, instead of being stuck in cell 4, which is supposed to improve driveability, but I havent been able to fully test that theory out since my transmission took a dump... Hope that helps.

 

Yeah, I can watch the BLM cell move in WinALDL. That's why I asked what the cells are used for. My idle is great right now...I finally got it pretty much rock steady at 700 rpm in P/N. It will hold that in gear, but it tries to drop off a little. Once I take it out of gear, I think that the IAC is fooling around with it because it will idle up to about 1000 rpm and then come back down after about a minute. I trimmed some fuel out of the VE1 table last night, but I haven't had a chance yet to see what how the new table affects the idle. There were several cells with BLMs of well below 128...like 110 to 117. The higher MAP cells were a little over 128, but didn't require much correction. I'll post the new table later when I get home. I am wondering if the throttle follower needs to be changed or if I need to mess with the IAC vs temp table some.

 

Regarding the Excel spreadsheet: There is one out there named "WinALDLVEfixer" that works well. You paste in your BLM table from WinALDL text file, paste in your current VE table, and it will calculate a new one VE tabl.

Jon Prevost also has a perl script that will automagically do it. You specify to it whether to use narrow or wide data, and it will pull it directly from the WinALDL text file. It works for '7747 or '8746 IIRC. I'll see if I can find that thread. It's here

 

I just looked for that WinALDLVEfixer and I didn't find it. Now that I actually have my spreadsheet set up, all I have to do is cut and paste BLMs, INTs and my current VE1 table (from the TunerPro RT BIN export feature) and it automatically calculates the correction factors and applies them to the VE1 table. It is really that simple and it only took me about 15 minutes to set it all up.