Webinar 204 MAF Rescaling

The academy has the tuner set table 12400 Pwr Enrichment EQ Ratio to a single number for the entire table while tuning for MAF only. In watching the webinar video 204, MAF Rescaling, I noted the commanded Lamda changed from 1.0 to 0.85 during the tuning process.

I'm missing something here......if Pwr Enrichment is set for a single eq ratio (table 12400 GM ECU), what commanded the Lamda to change from 1.0 to 0.85 while conducting the tune (video was tuning WOT above the ~5700 HZ region of the Eq Err scanner log).

Apologies for the slow reply Dan. You're correct that the EQ Ratio table is set to a single fixed value but that value is 1.176 which is a lambda target of 0.85. This is why you'll see the commanded EQ ratio switch from lambda 1.00 to 0.85 if you ha[p[en to exceed the PE transition point. This is explained in the webinar and I prefer to gather data under closed loop conditions and then separately under PE conditions. If you happen to log data as the ECM transitions into PE though it will result in a sudden and temporary error (which is why we recommend the method we do). To be clear this is not the only way of dealing with MAF scaling though. There's multiple ways of doing so including setting the ECM to permanently run OL or set the PE table to lambda 1.00. Personally I don't like running the engine under WOT at a lambda of 1.00 though.