AutoVe question

[DaddySS]

Well I have learned an awful lot from you guys and it has taken a long time to my 11:1 8.8 DCR 00 Camaro SS running well. On a personal note, the more I learn, the more I reallize I don't know!

Anyway, to the question. During auto ve, because you're in open loop, the PE from the CFOL table kicks in much earlier than PE in CL MAF. As a result, the VE table where the PE was taking place is off when you go to MAF and Closed loop.

How have you compensated for this - add to VE by the PE % during OL, calibrate the MAF to compensate, etc.?

[SSpdDmon]

I don't see how PE kicks in sooner in open loop vs. closed loop. PE is controlled by TP%.

If you're refering to richer values for the higher kPa columns in the CFOL table, it sounds like you're not simulating closed loop accurately. When tuning in open loop for closed loop, you really want to set the 158*F and greater rows to stoich (all the way across). That will simulate closed loop.

The concern with doing this then becomes: Are there times when MAP kPa's are greater than 85~90, but stoich is still being commanded? If you find situations like this, it's resolved by dropping the PE TP% Enable table for that RPM. So, take note of the RPM & TP% and adjust accordingly in B3616.

[DaddySS]

But if I read the directions correctly, you set the values in B3605 per the red rectangle which includes enrichment beginning at 65kpa. In closed loop, enrichment is via the TPS - at between 64 and 26% - often much higher 65kpa.

[SSpdDmon]

The instructions are one way to do it. Based on the tuning experience I've had over the past 2.5 years, I do it differently I guess.

As for the stock TP% enable being rather high, I most definitely agree. I usually drop it ~20% from stock in some spots as a starting point (start at 40% and move to 15% for the higher rpms). Again, this is for tuning a car you plan to put back to closed loop.

[DaddySS]

The instructions are one way to do it. Based on the tuning experience I've had over the past 2.5 years, I do it differently I guess.

As for the stock TP% enable being rather high, I most definitely agree. I usually drop it ~20% from stock in some spots as a starting point (start at 40% and move to 15% for the higher rpms). Again, this is for tuning a car you plan to put back to closed loop.

Thanks, I think that's what I'll do. 64% is much too high and next time I do auto ve I think I'll set CFOL to 1. as you said.

In the mean time, it was enlightening to see how much better you can manage enrichment and KR in OL, and provides a good model for setting PE enable TPS #s