3 bar OS - PE vs RPM and PE vs MAP (trying to get AFR right under boost)

[Chevy406]

First off, I apologize for this rookie question. I can typically find my answers with enough searching. This is my first time tuning with the 3bar OS. How do you setup the two Enrichment tables <EQ Ratio vs RPM> and <EQ Ratio vs MAP>? My assumption is to use target AFR in both tables (i.e. 11.7 afr at 8 psi boost on a 93 octane tune). Is it correct that the ECM chooses the richer of these two EQ tables and only uses that one? It doesn't combine the EQ tables does it?

My problem is that I've been reducing the VE table in order to lean it out from 10s under boost, and now the VE is less than 100 in boost areas. My P0101, 0102, and 0103 are set at 2-No MIL Light. I've considered reducing the MAF table anyway just to see if that would affect the AFR...

A little background on my hardware: 408 LQ4 shortblock; AFR225 heads; 236/230 XER cam on 115°; Victor Jr. with Accufab 4150; twin GTK-650 66mm turbos, air-to-air IC; 80# injectors; TH-400 trans; '69 Nova.

It seems to be running well during the limited street driving I've done - just a little rich under boost. The attached scan only has one WOT point at frame 2390 and it dipped down to 9.8 AFR. I would really appreciate some feedback on my tune before I take it to the track and lean on it with some slicks. On the wastegate springs it's making 8 to 9 psi and I'll be running 93 octane. I plan to run around 17 to 18° timing and target AFR around 11.5 to 11.7.

Thanks for all the help from this forum.

[Bill@HPTuners]

Correct, however in some operating systems it uses a slower reacting portion of the code for the BE so we recommend using the PE table for the fueling and BE more of a safety cushion than anything.

[redhardsupra]

...or you can just set both tables to the same values and eliminate this question.

[killer96z]

I thought the purpose of boost enrichment was to be able to have the ability to command different afr depending on boost level. If your cruising at 100 kpa with the bypass open you don't really want 11.5 afr, 12.5 would be fine.

[DSteck]

I use the BE in conjunction with PE all the time. I've never had a problem. I just make sure to enter PE first.

[Chevy406]

My follow up question then is it expected that VE values stay pretty flat from the 100 KPa point to 105+ KPa in their RPM columns? I guess I expected VE values to climb when in boost.

I'll just keep backing out VE numbers in cells below commanded AFR and don't over complicate it. Give the engine what it needs without "raping" the PE / BE tables.