What what point does the car go from open to closed loop under acceleration?

[truwarrior]

When does the car go from closed to open loop? Is it only under WOT and what throttle position would that be? Thanks.

 

[truwarrior]

Found this article...seems pretty good.

http://members.shaw.ca/costall/ECUprimer/ECU_ch5.html

 

[16g-95gsx]

Just a quick look at my logs shows somewhere around 50% throttle last time I checked on DSMLink. It might change from run to run, but I do remember looking at yesterday's log and seeing it.

 

[KeltonDSMer]

Yeah, I think it is like 30-50% throttle. I believe higher RPMs also bring it into closed loop, like over 3500RPM. I think this because I remember reading options for a chip and one was to keep the ECU in open loop at a higher RPM and throttle to allow the ECU to stay in open loop while cruising at 85+MPH to save gas.

 

[RuBiCaNT5X]

Open loop starts at WOT or at 90% throttle and over....

 

[16g-95gsx]

Wouldnt you want to stay in closed loop to save gas? By staying in closed loop the ECU automaticallly aims for 14.7:1 and adjusts accordingly. If you really wanted to get fancy you could get a WB02 and have it output an analog narrowband simulated output and run that to your factory o2 wiring, so that your front O2 readings were based off of a wideband output instead, so they'd be that much more accurate. But thats not the point of this thread I guess.

Perhaps rubicant is right, I might have passed the certain RPM when it kicked in, and I was logging quite a few things at the time causing it to read slower than it probably should. However I defiantely dont believe its 90% throttle and over, in fact I KNOW its not that, as my TPS signal wont read over 90% most of the time, and I still go WOT just fine every run. I still think its somewhere in the vicinity of 50-60% throttle, at absolute most I'm thinking around 80%. If you're pushing the throttle that hard you're intending to accelerate.

 

[LightningGSX]

Its a combo of TPS and RPMs, past a certain point, either will put you into open loop.BTW You'll be in open loop long before 90% TPS.

 

[KeltonDSMer]

Sorry, I switched open and closed loop around.
Closed loop=O2 sensor
Open loop=MAS readings.

 

[pneumo]

I've logged my cars extensively, and found the open/ closed loop threshold is at 40% throttle and above, or about 3900 rpm, whichever comes first.