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Tuning AF Ratios

24K views 21 replies 7 participants last post by  Kevlar 
#1 ·
I have been playing around in FP Manager since getting my flash pro a couple weeks ago. I recorded a couple 3rd gear WOT datalogs to play around with in FP Manager to try to familiarize myself with the software. Im running the reflash tune for now until I throw on a few more bolt-ons. Am probably planning on doing a dyno/etune in the future. I imagine that the way the reflash tune has the ignition and cam angles set is probably not bad...? So I have been looking at the fuel tables with the AF ratios and want to try to adjust my AF ratios. Now are these tables only used for adjusting fuel at wide open throttle (WOT Lamda Adjustment)? At 3rd gear wide open throttle looks like this...
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Running rich as expected from a generic Reflash tune. The suggested change tabe looks like this...
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Now if im understanding this correctly all of the fuel should be adjusted to try to accomplish the 12.46 AF ratio from the "normal table values"? Is this what the k24z7 likes at WOT?
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Here are the corresponding tables for the high cam also:
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I really haven't found much information as far as actual tuning with FP Manager. Most of the info I have found relates to setting up the hardware and software, but not much instruction on actually tuning. Am I crazy for wanting to figure our how to tune with this software? Or just stick with a dyno/etune like everybody else? But then where did these guys learn!?
 
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#2 · (Edited)
Adjusting the lambda tables will not do anything because in order to properly tune your ratios right you will need to adjust high fuel tables, low fuel tables, ignition tables, cam angles for both high and low cam, knock tables and so on and whem done right it would be done in small increments so you wont seriously screw the engine up but you have the right idea to get tuning done by someone that knows how to. It takes alot of know how to mess with this stuff and if you dont got it dont do it, but if you want to learn take it to a reputable tuner in your area and get it tuned and have someone show you how its done, the best way to learn is from someone that knows how to do it and can take you through it with ya

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#3 ·
The lambda tables work just fine. Just don't enrichen more than 12.50 afr.

FYI if it says you need to take away 10% fuel you actually need to add 10% fuel to fix it.

aka if the afr is 12.46:1 and your afr is 12.3:1, to get to 13:1 you need to adjust by +5.6%

so you'd SUBTRACT 5.6% from 12.46 in order to get the leaning out you want.

12.46 * .944 = 11.76

That would be what you would set the lambda to in order to lean out to what you want it to be.

It sounds ass backwards but it's correct.

Also THIS TAKES INTO ACCOUNT THAT YOUR MASS AIRFLOW CURVE IS CORRECT ALREADY. IF it's not you will get UNINTENDED afr fluctuations. Hondata help has instructions on how to resolve yoru afr curve from datalogs. It works the same for wide open throttle as it does for partial throttle when you're talking about tuning the curve.
 
#8 ·
So tuning AFM Wide Open Throttle is somewhat similar to tuning a map table in that an adjustment is needed for each rpm and MAP column? I've tuned MAP based lots with KPro but never MAF. I want to do it just so I can learn how. It would appear my closed loop looks decent but WOT is super rich. 10.5:1 - 11.x:1 AFR.

If I understand correctly, at 11.3:1 I would need to adjust by 13%. So would that end up being 10.85 AFR in the lambda tables?
 
#4 ·
I have tried running the reflash tune with both the stock air box and my short ram intake. It pulls harder up top and wot with the short ram intake installed (open Loop) but much less mid-range torque and responsiveness (closed loop). The stock airbox is the opposite, more torque and responsiveness in the mid range (closed loop) but not as much power up top and a wot (open loop). Soo I have had the short ram intake on and off a few times trying to decide which is better, but what would probably be the best is to tune the AFM curve with intake on because obviously I would rather run that than the stock airbox? Only other thing I have installed is a Q300 cat back. Would it be safe to say that tuning the AFM cure would be step 1 in the tuning process when running an aftermarket intake? That way I would still be running the "safe" reflash tune for now but it would function better with the AFM curve tuned to the intake.
FlashPro Help
 
#5 ·
If you want to run afm and not map, then yes tuning the afm curve is step numero uno in that process.

You can tell how bad your maf curve is by looking at your ltrim and strim values. ltrim with a perfect curve should be +/-2 , and shouldn't vary more than +/-5 day to day in different weather conditions
 
#6 ·
When starting a new calibration it doesn't give you the choice of afm or map based tunes like it did on the 8th civics. I read on the Hondata forums that it's because the 8th uses a combination of both. When looking through fp manager I could only access the high and low wot lambda tables which only shows afr and the target lambda. Only way I could get the high and low fuel tables was to click "show advanced parameters" under options and then go into calibration tab and click the map button at the bottom ( map tracing mabe? don't have it in front of me) other than that it I couldn't find a way to even adjust fuel.
 
#11 · (Edited)
Oh master, please enlighten us. What i said is exactly correct, you're also arguing against the hondata help file itself if you're saying this is incorrect.

The one important thing is you cannot and should not increase the WOT area lambda values higher than the closed loop areas.

If you've already adjusted your AFM curve to read properly (youv'e used the xy graph to tune the g/s accordingly at each specific voltage) then you have nothing to worry about as long as you adjust everything as i've said and don't increase past the limits.
 
#10 ·
Read the tuning guide on Flashpro help. FlashPro Help Your first step is to tune the AFM Flow table so that your Mean Short term fuel trims are within 1%. The computer will then (in closed loop) calculate the fuel needed to achieve a stoich air fuel ratio (14.7:1) based on the amout of air in (g/s) passing the MAF sensor. After looking at some of my datalogs I was running good in closed loop, but in open loop WOT I was running much richer than the commanded 12.46:1 AFR. What I found was that in tuning the AFM flow values in closed loop your dealing with between 1v-3.4v from the MAF sensor. BUT In open loop WOT the voltage was between 3.1v-3.9v. You have to adjust your AFM Flow values in the upper range so that you are achieving the commanded air fuel ratio. Adding more volume of air (g/s on your AFM Flow table) will command more fuel, Decreasing the volume of air will do the opposite and will command less fuel leaning your your actual AFR. Your goal in open loop is for your actual air fuel ratios to be the same as the commanded ratios in the lambda tables. Then and only then should you adjust the commanded lambda values to achieve the most power.
 
#12 · (Edited)
Read the tuning guide on Flashpro help. FlashPro Help Your first step is to tune the AFM Flow table so that your Mean Short term fuel trims are within 1%. The computer will then (in closed loop) calculate the fuel needed to achieve a stoich air fuel ratio (14.7:1) based on the amout of air in (g/s) passing the MAF sensor. After looking at some of my datalogs I was running good in closed loop, but in open loop WOT I was running much richer than the commanded 12.46:1 AFR. What I found was that in tuning the AFM flow values in closed loop your dealing with between 1v-3.4v from the MAF sensor. BUT In open loop WOT the voltage was between 3.1v-3.9v. You have to adjust your AFM Flow values in the upper range so that you are achieving the commanded air fuel ratio. Adding more volume of air (g/s on your AFM Flow table) will command more fuel, Decreasing the volume of air will do the opposite and will command less fuel leaning your your actual AFR. Your goal in open loop is for your actual air fuel ratios to be the same as the commanded ratios in the lambda tables. Then and only then should you adjust the commanded lambda values to achieve the most power.
tl;dr: graph afm voltage vs a/f corrected, and adjust the afm curve by the percentage the lambda values are off your commanded amount.

So if you're commanding 12.47 and you're getting 14:1 @ 3.5 volts, then you need to adjust that area by +11%

So if the g/s at 3.5 volts was, say, 140 then it should be 156'ish

For closed loop you graph AFM.v on x and STRIM on y and then adjust your AFM curve at those voltages based on the strim values at each 1/10th of a volt.

All my information is perfectly fine. As i've said already, if you haven't adjusted your afm curve properly then you should do that first, that's always the first step with afm cars.
 
#13 ·
Ok, so I was on the right track but when I graphed the ratios and made the adjustments it didn't seem to work as expected. I then noticed that in the 2013 ILX AFM Calibration, the AFM Flow Voltage maxes out at 2.56v. When I do a datalog the AFM.v graph has entries well past that around the 3.7v range.

I compared the 2012 Civic calibrations to the ILX calibrations and the AFM Flow Voltage tables are half the values of he 2012 civic calibrations, thus causing the table to run out of room an stop at 2.56v.

I posted this on the Honata forum and they advised a software engineer is looking at it.

Hondata • View topic - AFM Flow Voltage
 
#14 ·
At first I was thinking you weren't seeing the slider under the AFM flow values, and it was hidden behind your xy graph and couldn't see it... You have an ILX? When I try to open a new ILX calibration I see what your talking about "voltage" is spelled wrong when in the ILX calibration where it is not under a civic calibration. But also the ILX voltage indexes top out at 2.56 volts.
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Im not sure if you can run a Civic Calibration on an ILX...? Wonder if the ILX would let you upload a Civic Calibration.In either case Civic or ILX the AFM Flow tables have 64 columns, the voltages indexes are just different. This is how you fix it! Start a new 2012+ CIVIC stock equivelant Calibration. Save it somewhere. Then go back into your ILX calibration and open up the AFM Flow table. Right click on the table and then click on "Import from Calibration" Find the 2012+ CIVIC stock equivelant Calibration you saved. It will then ask you "This calibraton is a different ECU type. Do you still wish to import this tabe?" Click YES. Then it says "Load Table Index as well?" And click YES! You will then have the Index voltages and flow from the civic calibration and you can tune them from there.
 
#18 ·
At first I was thinking you weren't seeing the slider under the AFM flow values, and it was hidden behind your xy graph and couldn't see it... You have an ILX? When I try to open a new ILX calibration I see what your talking about "voltage" is spelled wrong when in the ILX calibration where it is not under a civic calibration. But also the ILX voltage indexes top out at 2.56 volts.
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Im not sure if you can run a Civic Calibration on an ILX...? Wonder if the ILX would let you upload a Civic Calibration.In either case Civic or ILX the AFM Flow tables have 64 columns, the voltages indexes are just different. This is how you fix it! Start a new 2012+ CIVIC stock equivelant Calibration. Save it somewhere. Then go back into your ILX calibration and open up the AFM Flow table. Right click on the table and then click on "Import from Calibration" Find the 2012+ CIVIC stock equivelant Calibration you saved. It will then ask you "This calibraton is a different ECU type. Do you still wish to import this tabe?" Click YES. Then it says "Load Table Index as well?" And click YES! You will then have the Index voltages and flow from the civic calibration and you can tune them from there.
After I followed your procedure I tried the calibration and the car just starts and stalls. Seems like there is something different between the ILX and Si.
 
#17 ·
I have my high cam AFR's dialed in pretty good, but am still playing with the low cam AFR's / AFM Flow... These "normal table values" are really only the suggested values @ WOT (>70% throttle) right? So at WOT map pressures from -26 to -4.3 should never occur?

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When loading a datalog the AFR's that display on the "WOT Lambda adjustment Low table" should all be near stoich to the left of -4.3 because these areas would be closed loop (< 70% TPS) at these map pressures right? These are here because there are no High and Low Fuel Tables like on a MAP based tune.
 
#22 ·
Hey Mikey,

It's all about the A/F Voltage vs A/F Table under Sensors -> AFM/Mass Air Flow.

You NEED to datalog a good fifteen to thirty minute drive in order to get an average short term fuel trim compensation for various 'cells' in the vehicle's tune.

After you datalog, import it, then go to advance graphs and click X-Y graph. Plot short term fuel trim vs AFM voltage and look at where the fuel trim is deviating from 0. This table indicates, generally, how you need to increase or decrease the G/S air mass in the airflow vs MAF voltage table.

For instance, if your short term fuel trim, on average, is 5% at 1.2 volts, then that means in closed loop (obviously), your ecu is having to add on average 5 % fuel to compensate for a lean condition at that particular voltage. This indicates to us that our MAF meter is not "tuned" or adjusted at the 1.2 volts interval in our MAF Voltage vs Air Mass table. So, we need to tell the ECU that at 1.2 volts, the MAF is actually seeing more air mass than it thinks it is. Adding 5% air flow (right click -> Increase by percentage) is an adjustment that should enable the ECU to fuel the engine appropriately after just reading the air mass without having to leverage the primary o2 sensor in closed loop to make the correction after the fact.

Does that make sense?

The same principal applies when you're tuning for open loop/wide open throttle. The target wide open throttle lambda/A/F table is just that, a target... If your AFM Voltage vs Air Mass calibration is incorrect at the specific voltage intervals that the ECU is seeing when the TPS %/MAP reading meets the WOT point, then your wide open throttle air fuel is going to be off. There is no use of the primary O2 sensor in order to make a change on the fly, like you would with closed loop operating.

The goal here is to pull up the target WOT lambda table, while looking at your datalog. Find your WOT point, usually a really high TPS percentage, then look at what the actual A/F under WOT table is showing you. If it's hitting a far leaner target than you're commanding, then you go back to the MAF Voltage Table vs Air Mass and add air mass to that voltage interval, again referencing your XY graph. Instead of using short term fuel trim vs AF Voltage, use A/F Ratio (or A/F Ratio Corrected) vs AF Voltage. The percentage deviation at those higher voltage points (which you would never see being used in closed loop) will guide how much you add or subtract from the air mass figures in the air mass vs voltage table.

Let me know if that makes sense - if you would benefit from screenshots I'm happy to provide them. Send over your datalog, and we can dive into it!

FYI I'm no tuning guru, I just have a foundational understanding of how this aspect works. If I've gotten any of this wrong, please let me know!
 
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