closed loop vs open loop - Performance Forum

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closed loop vs open loop
Friday, May 04, 2007 6:20 AM
whats the difference?

I know one is during cruising and one is during WOT.

What systems are running what sensors are running during each?



Scott

When I boost, you boost, we boost
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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Re: closed loop vs open loop
Friday, May 04, 2007 10:11 AM
Closed loop refers to how the program is running in the computer. Each "loop" examines sensors to determine how the engine is running and how to adapt. During cruising it's putting just the right amount of fuel in through the injectors, monitoring spark levels, etc.

Open loop operation means the computer is not running throught the sensor read and adapt loop, it's just using numbers from it's internal tables for everything. So fuel injected is a constant number determined by engine speed. Things like air temp, engine temp, oxygen sensor get ignored.

In more complicated engines there are other sensors that may or may not be ignored during open loop operation. For instance the 4 bangers do not have MAF sensors, where the V6 engines do. I forget how EGR is set during open loop; I want to say closed, but I could be wrong.



Re: closed loop vs open loop
Friday, May 04, 2007 4:59 PM
Keeping it simple.

Open loop operation ignores the O2 sensor.

Closed loop uses feedback from the 02 sensor to adjust timing and fuel.


.
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Project S-Bird
Re: closed loop vs open loop
Friday, May 04, 2007 5:01 PM
so both use the TPS and MAP



Scott

When I boost, you boost, we boost
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
You have been banned from NEJBODY.
You've displayed wayyy too many acts of pushing people to their limits.
It's never cool to tear people down for what they want to do.
NEJBODY is a team. We're not the same as JBO where everyone bashes on eachother.
I'm surprised you show up to our meets after half of the things you say on here.
Re: closed loop vs open loop
Friday, May 04, 2007 6:43 PM
RaGiN Z (the fake 05) wrote:so both use the TPS and MAP


Yes.


15.3 @ 89.97mph - '01 SFGT
'98 Acura 1.6EL Sport 5M Y7/Y8 mini me
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