Running Closed loop
Extreme HDF Member
Joined: Sep 2010
Posts: 14,744
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From: Phoenix '53, '88, '09 Big Twins
from wiki answers.com
" Once the engine has reached operating temperature, the computer switches to 'closed-loop' control. This means the computer receives feedback from an oxygen sensor as to whether the mixture is too lean or too rich, then it makes adjustments, then checks the sensor again, then makes adjustments, and on and on in an infinite loop"
end quote
open loop mode is when the motor is being operated to "preset" parameters by the ECU and the sensors are not used, or sensor input is limited.
mike
" Once the engine has reached operating temperature, the computer switches to 'closed-loop' control. This means the computer receives feedback from an oxygen sensor as to whether the mixture is too lean or too rich, then it makes adjustments, then checks the sensor again, then makes adjustments, and on and on in an infinite loop"
end quote
open loop mode is when the motor is being operated to "preset" parameters by the ECU and the sensors are not used, or sensor input is limited.
mike
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Cruiser
Joined: Jan 2007
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From:
Thanks, back when I purchased my bike the dealer installed a HD Race tuner on my bike. They plugged my O2 sensors and my bike was running open looped. It sounds like from your explanation that I would get better performance with a closed looped system.
Closed loop will always be better than open loop. But here's something I found interesting in Donny Peterson's book on the Twin Cam;
I'm paraphrasing this at best, but that riders with closed loop who sit at red lights and rev their engine are actually forcing their bike back in open loop and cause more heat.
I'm paraphrasing this at best, but that riders with closed loop who sit at red lights and rev their engine are actually forcing their bike back in open loop and cause more heat.
Extreme HDF Member
Joined: Sep 2010
Posts: 14,744
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From: Phoenix '53, '88, '09 Big Twins
old habits die hard...older bikes with cams and or lightened flywheels often needed to be "blipped" before leaving a stop ( and in the case of bikes to mid 60's didn't have acceleration pumps on the carbs).
Not really required with the newfangled EFI...on my Panhead I have to "try" to keep it running when at a stop, no accel pump...but I do have manual control of timing.
Mike
Not really required with the newfangled EFI...on my Panhead I have to "try" to keep it running when at a stop, no accel pump...but I do have manual control of timing.
Mike
Last edited by mkguitar; Feb 13, 2011 at 06:09 PM.
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I could be wrong but I dont think its all about operating temperature. I think in situations like wide open throttle or even just hard acceleration the bikes with O2 sensors are in open loop and they are in closed loop at cruising speed to lean the mix and get better fuel mileage.
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What I was getting at was, running the bike in open loop does create more heat, because the ECM is no longer hunting for the prefect AFR.
So, in turn that does create heat because the ECM is in open loop.
So, in turn that does create heat because the ECM is in open loop.
