There is a bit of confusion over the different modes the computer can enter so im going to try and clear this up for everyone.
MAF Closed Loop-MAF is Active, Main fueling O2 sensors are ActiveMAF Open Loop-MAF is Active, Main fueling O2 sensors are Inactive or removed
- Most Stock LS1's run in this mode corrections are made by the MAF, VE table & O2 sensors at part throttle & from 4000 rpms the MAF takes control of fueling based on your PE, OLFA, COT & any associated adder tables
Speed Density Closed Loop-Maf is inactive, removed or Failed, Main fueling O2 sensors are Active
- Many use this mode when the o2 sensors cannot be trusted for whatever reason ie Big cam, LT's, etc.
Speed Density Open Loop(OLSD or SDOL)-Maf is inactive, removed or Failed, Main fueling O2 sensors are Inactive
- Many revert to this mode after doing VE tuning in SDOL mode so the computer can make some corrections for fueling
- Unless using an HPTuners Custom Operating system you will be stuck in the Low Octane Table
- Unless using an HPTuners Custom Operating system you will be stuck in the Secondary VE Table(where applicable)
Bottom Line is to remember Is Speed Density mode doesnt dictate if your in Open Loop or Closed Loop.
- Most will say this is best for VE tuning because you have complete control over what the engine wants to do.
- Setup your OLFA tables as you'd like to drive around town
- Setup your PE tables as you'd like to drive around town
- Just remember the computer will always command whatever table is richest so keep an eye on any adder/multiplyer tables that may be in effect such as Cat Over Temp.
- Unless using an HPTuners Custom Operating system you will be stuck in the Low Octane Table
- Unless using an HPTuners Custom Operating system you will be stuck in the Secondary VE Table(where applicable)