open and closed loop, at what point do they shift from each other? Options

[batcavee00]

title says it all, any one know when the car (94 gt, 5spd) is in closed loop and open loop? sorry for the noob question, not really a noob i just dont know... lol


i know some cars change between throttle percentages, others by temperature, etc....


how does the closed loop and open loop work on our cars?

[jordisonjr]

Noob Question?
I don't even know what closed loop and open loop are haha. When it comes to cars at least.

[richee3]

Open loop is when the ECU is running on a base map before the engine warms up. Closed loop is when the engine has warmed up and starts relying on input from all the various sensors. That's how it is on the BEAMS, anyway. The 5S could be different.

This post has been edited by richee3: May 10, 2012 - 12:33 PM

[presure2]

i tried to answer this as best i could in the PM i replied to, but richee has the basic idea, it also goes into open loop @ WOT, and i also believe that it uses open loop from around 70% throttle and a certain RPM, ect.

[lagos]

Google Control Theory to learn more about it, but the basic idea is that closed loop takes into account input signals while open loop does not.

Here
http://en.wikipedia.org/wiki/Control_theory

[batcavee00]

I just wanted to know because my ecu was fighting my safc2 in closed loop tuning. I got around this issue by simply disconnecting my O2 sensor (force open loop). So far so good, my safc2 is working nicely in low and high map. No more jumpy afr in low map. Now I can tune my low and partial throttle afr to wat I want. Just wanted to share that info...and thanks for all the replies

One more thing:
im not responsible if sumthing happens to your car if u try wat I did, do it at your own risk lol