Hello,

I am getting very close to a respectable tune (I think) on my 165 running arap. However I am still having problems getting the tune in line when the load for a certain airflow varys much off of cruise.

For example, when I am cruising on the highway at 70 the MAF will report ~45 g/s and the load will be ~100 (2200RPM). But when I reach the same airflow in 2nd gear at 20 or 30 miles an hour the LV8 is higher, more like 150. However the INT goes up sharply on the higher LV8 conditon whereas the cruise condition seems to be right on (128BLM,128INT)

In closed loop it seems that the only way to effect how BPW changes with load is to change BPW offset vs. BATT voltage or BPW offset for small PW's.

Is there another table I am missing that simply relates BPW offset vs. LV8?

Thanks.

 

Is your foot moving during the problem in 2nd gear? Or have things pretty much stabilized (although the RPMs are still climbing due to higher load)?

If stabilized, it could be a problem with either of the PW offset tables, but probably with the VBATT table (unless your cruise PW is small enough to be included on the small PW table). In this situation, the smaller PWs at 100LV8 are too big, so, you'll have to REDUCE the VBATT table (to equalize the low load and high load INT/BLM - but it will equalize at a higher number), and INCREASE the MAF Table, OR REDUCE the injector constants some to bring BLM back down to 128 - I recommend the first, but changing the injector constants can help you see the result at those 2 points quicker if you need to convince yourself that changing the MAF tables is worth it.

If not stabilized, and your foot has very recently moved, then your AE might need some work (increase it).

 

LV8 is used in the timing calcs., not fueling.

If you BL's are resonable, then your done.

 

Yeah, LV8 isn't directly used for fueling, but you are seeing a problem that is Load (or PW related). The actual LV8 value doesn't matter, and in $6E there isn't any way to adjust fuel via LV8. If I recall correctly, you can make BLMs use either LV8 or Airflow, and of course RPM for the block boundaries. I prefer to set it to use LV8 boundaries for BLM storage, as it can cover this kind of problem.

 

Awesome answers! Thanks.

I will try to correct by lowering the VBATT table and then changing the MAF tables back to get 128's again.

Is there anything else I should know about before changing the BLM cell structure to function with LV8 instead of MAF? Like would the cell boundary entries in Tunerpro need new defenitions? Or could I just replace the Airflow boundary numbers (13, 21, 34) with LV8 numbers (50, 100, 150)? I think I might like to try this...

Thanks again -- really helpful!

 

There's a scaler in there for changing the LV8, but unless your really well versed in the MAF stuff, I'd suggest leaving it alone. Once you get to dither that, then you need to watch the Burst Knock Retard stuff depending on what you're doing, and that can get exasperating, for even the patient.

Unless you have an ecm bench, and a WB to verify your results, I'd suggest staying with the *mundane*.

The MAF systems with the lack of really *seeing* load in the Air Flow cals., just will always leave a lil on the table, from what I've seen. You can only get so close with them. Not to mention with any transistions, they're just not that accurate (well, in the early codes).