Maf Comp and AF ratio adjustment

[moi1463]

I did the initial maf comp adjustment for cruise then started to tune for an even AF ratio. The thing is that I don't have anyway to log true boost. So I read somewhere that I can change the Maf comp at a specific Hz to match up with the boost according to my boost gauge. But by doing so, my AF ratio is now way off, should I keep messing with the openloopmaxoct to even out the af ratio or go back to the uncorrected maf comp and not worry about the boostest? First file is the uncorrected maf comp and second is corrected maf comp to match the boostest to my boost gauge.

 

[gofer]

Seems to be the common thing around here but for whatever reason nobody is updating their firmware. Its not a MUST but it just makes tuning that much harder on yourself, I figure if you pay $500 for ECMLink why not use the best version of it you can?

First download the most recent stable version v3.21.40 and then download early access v3.21.109 from the ECMLink Downloads page. After doing this you'll want to update your firmware as well but to do so its a bit trickier than just clicking a link.

1. You'll want to submit a firmware request and to do it requires you to connect to your cars ECU. Click ECU from the drop down and click Create Firmware Request... paying close attention to where its saved on your computer.
2. Request Firmware Upgrade... and select Choose File and find your firmware file you just saved.
3. Download the new firmware to your desktop or somewhere you can easily access it and then open up ECMLink.
4. Click the ECU drop down menu and select Upgrade Firmware and then pick the file you just downloaded while your connected to the ECU in the car.

Lets crawl before we can run here, post an idle log of the car completely warmed up after you download the new stuff. After you do that then we'll get into WOT logs/tuning. To help with those WOT logs above I've got to know what your boost gauge is showing between 5k and 5.5k to get your MAFComp sliders lined up accurately.

 

[moi1463]

Oh thanks, I didn't know about the early access version or the firmware. Got those things taken care of and here is the idle log. I went back to square one to set the maf comp to get .24 gm/rev and set the injector closer to 330 usec deadtime. Although I could only able to get it to 300 usec and keeping the fuel trim close to 0%. My next step is to take a cruise log at closed loop to adj the maf comp. Anything else I'm missing?

 

[gofer]

That idle log looks good, this is me being picky but you could adjust the TPS to EXACTLY 0.63v and back the BISS out a bit to get the ISCPosition to 30-. It looks like you're ready to do a 15min. cruise log, don't forget to adjust your OpenLoopThreshold settings in DA before you go.

[Threshold 1] to 1.13 across the RPM range.
[Threshold 2] to 1.13 across the RPM range.
[TPS Threshold] to 51.1% across the RPM range.​

 

[moi1463]

Okay, I went on a long cruise and adjusted the maf comp along with the tps volt to achieve the isc position at 29-31. I did have to adjust the deadtime and took off about 50 usecs to keep the FT around 0%. Did I miss anything else for this initial setup?

 

[gofer]

Things look good. In my opinion you should richen up your OpenLoopMaxOct DA map from 11.3:1 to about a 10.8~11.1:1 AFR, then do a WOT pull running 5psi LESS than what you want to. Then we'll see how everything looks AFR/timing wise and make some adjustments. You still need to tune the higher Hz points in your MAFComp so BE SURE to watch your boost gauge from 5k to 5.5k during the WOT pull, that way you know where to adjust them to.

Note that if you're still running the stock t25 then just set boost to where you want it and do a WOT pull. Just be sure you are watching where the boost is at from 5k to 5.5k...

 

[moi1463]

Sorry it took me so long to get some wot pulls, been crazy busy. I did two back to back pulls, not all the way to redline though. I adjusted the map to what you suggested and at 5 and 5.5k my boost gauge was showing 15.5-16 psi. I'm running a small 16g.

 

[gofer]

Your saying actual boost from 5k to 5.5k was 16psi but your BoostEst being logged is saying that it was 12-12.5psi. Thats fine, it just means we're going to have to do some math to get your MAFComp sliders where they need to be.

Heres the equation to do it...
((actual boost + 14.7) / (boostest + 14.7)) - 1 = percentage change to MAFComp slider

1. In the WOT pull log get the selector as close to 5k RPM as you can, the closest you can get in the log you posted is 5007rpm (@ 72.016 seconds into the log). Then you take note of (3) things when the engine was at 5k RPM, they are MAFRaw (Hz), BoostEst (psi), and Actual Boost (which is why you had to watch your gauge).
2. At 5k your MAFRaw = 1328 Hz, BoostEst = 12.8psi, Actual Boost = 16psi so now its time to plug everything in.
   ((16 + 14.7) / (12.8 + 14.7)) - 1
   
   = (30.7 / 27.5) - 1
   = 1.12 - 1
   = 0.12 or +12%​
3. Now you look back at the MAFRaw reading at that point in the log (1328Hz) and open up your MAFComp tab. Find the 1300Hz slider and increase it +12% from where it was, which in your case it was at 0. So bump it up to 11.7%.

So you do ALL of the above all over again but this time at 5500rpm.

5k your MAFRaw = 1470.8Hz, BoostEst = 12.2psi, and Actual Boost = 15.5psi
= ((15.5 + 14.7) / (12.2 + 14.7)) - 1
= (30.2 / 26.9) - 1
= 1.12 - 1
= 0.12 or +12%​

Before...

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After...

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...just copy/paste this into your MAFComp table and it will change them for you.

0 6.2
50 5.5
100 3.9
150 3.1
200 2.3
250 1.6
300 0.8
400 0.0
500 0.0
600 0.0
700 0.0
800 0.8
900 2.3
1000 4.7
1100 7.0
1200 9.4
1300 11.7
1400 11.7
1500 11.7
1600 11.7
1700 11.7
1800 11.7
1900 11.7
2000 11.7
2100 11.7
2200 11.7
2300 11.7
2400 11.7
2500 11.7
2600 11.7
2700 11.7
2800 11.7
2900 11.7
3000 11.7
3100 11.7
3200 11.7
3300 11.7
3400 11.7
3500 11.7
3600 11.7

At this point your car is going to be running a VERY conservative tune so its going to be RICH on the WB. After you make the above changes do a WOT pull from 2.5k to 7k (redline) at 100% throttle and we'll start working on your AFR's.

 

[moi1463]

Sorry the pull didn't quite get to 7k but hopefully it is good enough. I did notice the intake temp was a little high, since it's pretty hot here today. I read that for every +10 deg the boost drops 1psi, so I think right at 5k, the boost is right on. Do I need to adjust the maf comp a little more where it is a little low before and after 5k? I also noticed a bit of knock right when I went wot, should that be a concern? Thanks for all your help.

 

[gofer]

Go to your ALS/KNCK tab and adjust your knock sensor settings to...

Activate at RPM: 3000
And TPS: 30%​

Your coolant temps are getting up there, don't start beating on your car if they are above 210*. What amount of boost do you plan on running, what its set at now or do you plan on going to 21-22psi?

 

[moi1463]

I have a profec-b boost controller and would like to run 16psi for normal everyday and 21-22 for here and there. I don't know why the coolant temp is getting up that high, usually it'll stay around 210, and today wasn't even that hot, just 80* here.

 

[gofer]

Adjust your ALS/KNCK tab settings to activate the knock sensor at 3,000 rpm and 30% throttle.

Just click the link and save it to your ECU and do a WOT log with the new fuel/timing tables, the flatter the road the better. I hope you know that a typical shop would charge $250+ for this...

moi1463 new DA maps

 

[moi1463]

Thanks for all your help, I really appreciate it. I get the basic concept of this, it's just that I don't have any way of telling if I'm doing right or not, good thing that you're able to take some time and show me the way. I did two pull for consistency. This is where I had trouble with before where my wb gauge is basically stuck at 9.7-9.8:1 and no matter what I do to the DA MaxOct, it'll still read right around there. The AFRatioEst changes, but I'm told to never go by that.

 

[gofer]

The AFRatioEst is pulled directly from your DA OpenLoopMaxOct table, its just showing you what AFR's your ECU is shooting for. Its obviously impossible for me to be sitting in the car and watching your boost gauge to verify boost from 5k to 5.5k, but if what you say is true (16psi), something else is wrong. With MAFComp adjusted correctly now your AFR's should reflect what your DA map is trying to achieve, since its not there is a problem elsewhere. Typically the problem is mechanical, more specifically a fuel pressure issue, and from looking at your mods list its almost evident it is. You're running a Walbro 255 fuel pump with no adjustable fuel pressure regulator, so the stock one you've got on there is being overrun by the big ass pump which is why your AFR's are ALWAYS rich.

Replace the fuel pressure regulator with a FueLab or AEM afpr (get a gauge for it too) and set it to 43.5psi, then post a log. I bet your rich condition disappears and your WB AFR's start tracking what the ECU is trying to achieve.

 

[yukiz]

Very helpful thread..... Subscribed

 

[moi1463]

I was afraid of the fpr issue. I did do a search of the issue to see if I will need one or not, and from a few people, they said they were fine without having one. But this is proof that I do need one to control my fuel better. That also explains why I do not feel much of a horsepower increase difference between the two turbos. I'll get a fpr along with a downpipe and resume the fine tuning along with your help . Once again, thank you for the time and effort you have given me.

 

[moi1463]

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Finally got some time to work on my car. Got the fuelab regulator installed and went for a little test drive. You are correct about my stock regulator being overrun by the pump. Although I didn't get to do a complete pull all the way to 7k, I already noticed the difference it made with the regulator. It was getting really hot plus traffic was getting worse since it was close to rush hour. Hopefully you'll have some time to help me further on tuning. Thanks a mil.

Here I did a couple pulls at night when it was cooler. It's still a bit richer than what I'd like to be, take a look. I changed the map a little bit to get closer to 11.1 but still, it sits at 10.6-10.7 should I keep increasing the map to get closer to 11.1?