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Just curious is there a way to stop the computer from compensating for performance mods? Don't really see the point of adding a CIA or other things just to have the computer compensate for their changes.
 

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What does the Central Intelligence Agency do for your Commander's performance anyway. (I got to find out about this mod).
 

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What does the Central Intelligence Agency do for your Commander's performance anyway. (I got to find out about this mod).
FUNNY GUY :rofl:
 

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Just curious is there a way to stop the computer from compensating for performance mods? Don't really see the point of adding a CIA or other things just to have the computer compensate for their changes.
I'm not sure I understand what you are asking. Can you elaborate a little more?
 

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Ok,now that we got that CIA..CAI stuff straight.

I believe that more air flowing in and less exhaust back pressure would still be of a mechanical advantage. Are you of the opinion that the computer would restrict this in any way or do you think that it would modify the spark curve or fuel delivery system to counteract the better airflow. An engine is basically an air pump with internal combustion to power it.

The two most common power adders for engines both increase the airflow as well as stepping up the fuel delivery. A blower/compressor does it mechanically and NO2 or Nitrous oxide does it with extra oxygen in the intake, also with more fuel delivery.

Lets see what the smarter and more experienced fellows of this web site have to say to this subject.
 

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I'm not smarter or more experienced, but I could make something up that might sound good, if you want.
 

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The argument of the ECM learning of modified inputs and negating them is an old argument with no substantiation I have found.

The ECM function is basicly two levels.
1. Open loop: This is when the ECM is operating on a pre-written program.
It operates in this mode until various parameters are met, with the primary/key info being coolant tempurature.
Once coolant temp. has reached a predetermined point, the ECM looks at that info, the oxygen sensor info, and inlet air temp.
When all parameters are met, the ECM goes into.......
2. Closed loop.
This means the ECM is taking all the various sensor information to make fuel mixture adjustments. The ECM exists for one primary purpose. Its mission is to always try to maintain the perfect air/fuel ratio depending on load/throttle position and on & on.
It looks at the results of its decisions based on the front oxygen sensor readings.
The purpose of the after catalyst oxygen sensor is only to verify a catalytic action has occurred between it and the front oxygen sensor.
The rear sensor has nothing to do with computer changes and I only mentioned it to answer any potential questions.

So much for background.
A cold air intake can improve performance because the AIT (AIR INLET TEMP) SENSOR information causes the ECM to richen the fuel to air ratio. This is to compensate for the cooler(denser) air. The denser fuel/air fills the cylinder more than a hotter/thinner mixture would. Result...a bit more power. Because you now are making the same power with say a 18% throttle position as opposed to say a 20% throttle position, you may also see slightly better mileage. ( Slight means 2/3% so don't get too excited here)

Remember, the ECM doesn't care how it got the perfect air/fuel mixture, it's only trying to maintain it.

Exaust mods....Typically, there is no or very little power to be found with any after catalyst system. Makes the driver happy, sounds cool, causes loss of mileage cause you can't stop playing motor music.
Computer sees no change, and ignores it.
The primary exaust flow enhancement is replacing the restrictive manifolds with headers.
You could even attach them to the stock catalysts and enjoy a power increase.
Now, a cat back system can help performance because now the exaust is getting to it.
But, the computer doesn't care, it just wants acceptable o2 readings and its happy.

3. ECM parameter changes:
Generally, the information coming from various sensors is altered before it enters the ECM
This way, a richer mixture can be introduced at a lower % of throttle opening.
Also, ignition advance curves can be altered to bring advance in a bit quicker. This additional advance works well with the altered coolant temp readings and can increase power. I might add, if the supplier of the computer modification recommends a cooler thermostat, he is making the suggestion based on the more agressive advance curve causing the potential of pre-ignition (spark knock).
I recommend a lower temp thermostat to prevent this possibility.

You should notice I have continually highlighted the fact the ECM is trying to do one primary thing, achieve/maintain the perfect air/fuel ratio.

By altering its information it 'thinks' it is succeeding, so it happily goes about its business.
It will not undo any reprogramming.
It will not go back to its old self again.

I simplified this the best I could for the not so mechanically inclined.

Rob
 

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See I told you some smarter, more experienced fellow would chime in with the answer.
 

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That's what I was going to say....just kidding. I figured you'ld school us, Robby. I really enjoy reading your explanations.
 

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Thanks Robby for your wisdom!
 
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