Fuel injection? Open or Closed loop?

[art leong]

Originally Posted by Dickens

Sorry did not understand this high level question

I believe that in my case at least. If I run in closed loop at low rpms the O2 sensor is to close to the end of the collector. When idling, the over lap allows air to get to the sensor causing the mixture to show very lean. It doesn't read correct till about 4000 rpms.
I put a 4 foot extension on the collector to tune it at idle.
If it was in closed loop it would tune the mixture all wrong. Plus most (if not all) ) O2 sensors don't read fast enough to correct going down a dragstrip. RPMS and load are constantly changing.
I get back from a run. Read the data, then correct it for the next run. If I'm trying to get every .001 out of it. If not I just look at the logger for anomolies and if there are none, leave it.