Stock air intake vs. K&N FIPK

From what I've seen, back to back dyno runs can easily move 5rwhp or tk up/down. The dyno run here does look screwy. Since both runs are screwed up the same way, I do believe that you can conclude the K&N FIPK is giving you ~ 6rwhp over stock. As far as a reliable hp/tk reading for your car, I'd be tossing those results out.

Nice test, thanks for sharing.

hotmustang331 said:

the EEC adjusts for idle when the rear 02s are in use...it tries to get 14.7. My idle A/F for instance on Tims dyno was 18 lol. Before cams my A/F at WOT was 14-15. As far as im conserned the EEC does NOT adjust WOT trims. The preditor cant adjust the A/F eitherunless its manually set.

A/F is not all controlled by the EEC. If the A/F goes lean after a FIPK it generally means that there was a flow increase, meaning more air going into the engine but no more fule was added. At WOT the car goes into open loop, it refers to its base settings. thats why cars go lean after induction mods, a flow increase with the same amount of fuel = leaner. Thats the theory anyways...and in my car this was reflected. if you leave your cats and rear 02s functional then your idle A/F SHOULD stay at 14.7...WOT is different.

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ABSOLUTLEY WRONG!!! The purpose of the MAF is to determine the Mass of the air flowing in. Unless you screw up the reading of the MAF sensor by turning it, introducing turbulence by adding a bend in front of it, or contaminating it with oil from the filter the A/F is perfectly capable of adjusting for the increased air flow. The open loop base settings you refer to is the stabalized_open_loop_fuel table. This table depends on two things to decide what the a/f should be. RPM and the reading from the MAF. Well actually three things if adaptive was not turned off while tuning, which it should be. The third thing is the fuel adjustments that the eec learned during the last closed loop cycle. If adaptive was not turned off during tuning these adjustments WILL be applied back to the a/f ratio during WOT. Also this learning is done via the front o2's. The rear o2s have nothing to do with it or any other idle functions.

CanadaStang said:

Yes a/f is controlled by the ECC, open loop is only used until the engine is warm, not at WOT.
The a/f will be a little on the lean side after installing an CAI b/c it needs time to relearn and adjust for the increase in air. After about 30 miles of driving or if you reset the EEC, about 10 miles, it will adjust to the new CAI.

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This is also partly incorrect. WOT is in open loop as well as startup. Basically you are in open loop anytime you are not in closed loop. The EEC shouldn't need to relearn anything if the MAF reading has not been thrown off. The releraning everyone refers to is actually designed to adjust for small corrections to the MAF reading. My first guess by looking at the orginal posters dyno charts would be to look for a vacuum hose that may have worked loose during the second set of runs.

jstreet0204 said:

ABSOLUTLEY WRONG!!! The purpose of the MAF is to determine the Mass of the air flowing in. Unless you screw up the reading of the MAF sensor by turning it, introducing turbulence by adding a bend in front of it, or contaminating it with oil from the filter the A/F is perfectly capable of adjusting for the increased air flow. The open loop base settings you refer to is the stabalized_open_loop_fuel table. This table depends on two things to decide what the a/f should be. RPM and the reading from the MAF. Well actually three things if adaptive was not turned off while tuning, which it should be. The third thing is the fuel adjustments that the eec learned during the last closed loop cycle. If adaptive was not turned off during tuning these adjustments WILL be applied back to the a/f ratio during WOT. Also this learning is done via the front o2's. The rear o2s have nothing to do with it or any other idle functions.







This is also partly incorrect. WOT is in open loop as well as startup. Basically you are in open loop anytime you are not in closed loop. The EEC shouldn't need to relearn anything if the MAF reading has not been thrown off. The releraning everyone refers to is actually designed to adjust for small corrections to the MAF reading. My first guess by looking at the orginal posters dyno charts would be to look for a vacuum hose that may have worked loose during the second set of runs.

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While yes the EEC is in open loop at WOT it still uses the last value that it was using in closed loop, I just didn't feel like typing up an entire page as to how the EEC adaptive table works. The EEC needs a new adaptive table to work from in order to make the correct adjustments to the a/f. If the new fuel requirements are not in it's stored table then it cannot correct from them. It will in time however correct the stored table but it will do this much faster if the table is wiped out by resetting the EEC. Here is a great article on how the EEC adapts to changes. Read it and you will see what I'm trying to explain. http://www.mustangworks.com/articles/electronics/eecAdaptive.html

CanadaStang said:

While yes the EEC is in open loop at WOT it still uses the last value that it was using in closed loop, I just didn't feel like typing up an entire page as to how the EEC adaptive table works. The EEC needs a new adaptive table to work from in order to make the correct adjustments to the a/f. If the new fuel requirements are not in it's stored table then it cannot correct from them. It will in time however correct the stored table but it will do this much faster if the table is wiped out by resetting the EEC. Here is a great article on how the EEC adapts to changes. Read it and you will see what I'm trying to explain. http://www.mustangworks.com/articles/electronics/eecAdaptive.html

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I've read that article years ago, and while it gives the basics, it is a very high level explanation.

You are correct, but the time it takes to learn is not nearly what people think it is. It is seconds, not minutes or days. And the last value that you are refering to is a correction factor, not the commanded a/f ratio, for example the stock eec tune commands 12:1 a/f ratio at 5k and 100% load. If the last adaptive value at idle was 0.98 then it will multiply that times 12 to get the new value.

The stock adaptive strategy is setup like this.
In closed loop operatation the eec is setup to make corrections to the a/f ratio. It does this by taking in what it thinks is coming through the MAF the and adding the amount of fuel it needs to create a 14.7:1 a/f ratio it then reads the a/f ratio with the o2 sensors and then creates a correction factor. The EEC will learn the correction factor by applying it to the addaptive table, BUT the stock tune is setup up to ONLY learn in low load and rpm conditions meaning not much over idle. It then applies it back to all areas of the load rpm table. The learning is also time based and the cell that applies correction back to most of the table is set to start learning after 10 seconds, so 10 seconds after you crank it up it has already applied a new addaptive value that it is going to apply back to the WOT run. That is why it is common practice to turn adaptive off during tuning so that you are dealing with commanded fuel values not commanded + or - addaptive values.
It is also common practice to change the adaptive strategy to make all cells in the load/rpm table to learn from their own reference table.