LSJ-T: no luck calibrating MAF (Airflow vs. output frequency)

[jrsmith]

I've been having some difficulties calibrating the MAF. #60 injectors are properly setup now. I've followed the guide on redline forums by user 04Redline but I can't seem to get the AFR stable. The first thing is that I don't know how much to raise or lower the numbers, if for example it's showing +8.8 (percent) i'm not sure how high to raise the airflow in the table. I already tried increasing by percent but it's always jumping around & not being predictable.

What's driving me crazy now is that I had the 1800 & 2100 hz dialed in, was just under 14.7. Now an hour later when I do a log it's showing steady -12.5 in the graph & ~12.60 afr. I'm attaching my current tune & recent log showing the 12.60 afr.


joel turbo F.hpt6 #5.hpl

[cobaltssoverbooster]

if you set up the histogram correctly then you just highlight the recorded data and copy it from the scanner.
when you go to the editor, you right click the first maf cell and select the paste special / multiply by percent half. Save as new file, flash to car and test again.

you still don't have our histograms setup correctly. try watching some of the videos on setup from the lnf bible. the ecu's are different so tables will change or not exist for you but one of those videos is all about scanner setup and will help you set your scanner up the best.
there should be a link in my signature to the bible threads

[jrsmith]

Thanks, I figured out the paste special. Makes sense now. Could my purge solenoid be messing with the numbers to make things inconsistent?

[ECaulk]

are you running an open bov or recirculating bov?

[jrsmith]

oh right...I got one of those 50% recirc/bov ones. I guess i'll have to change how i'm logging. Totally forgot about that.

[jmc2010]

I'm not even seeing a MAF hz with WB Error Correction histogram. Where are you copying your numbers from? Also, you really want to be logging this stuff from steady state driving only, unless you have hella filters setup. Going from 20% throttle to 40% back down to 30% in just a few seconds adds tons of transient data. You're then correcting for that, and its got you all over the place.

[steelmesh]

I've been having some difficulties calibrating the MAF. #60 injectors are properly setup now. I've followed the guide on redline forums by user 04Redline but I can't seem to get the AFR stable. The first thing is that I don't know how much to raise or lower the numbers, if for example it's showing +8.8 (percent) i'm not sure how high to raise the airflow in the table. I already tried increasing by percent but it's always jumping around & not being predictable.

What's driving me crazy now is that I had the 1800 & 2100 hz dialed in, was just under 14.7. Now an hour later when I do a log it's showing steady -12.5 in the graph & ~12.60 afr. I'm attaching my current tune & recent log showing the 12.60 afr.


joel turbo F.hpt6 #5.hpl

I chased LTFT for a bit beating myself up, until I found I had a cracked turbo manifold. When I repaired all the leaks, upgraded to ARP exh manifold studs and a copper gasket, I am running +/-1 LTFT above idle, cruising.

If you have any air leaks or maintenance issues, you will never get stable fueling in closed loop.

[AP83]

Your data looks crazy in my scanner. None of my setup works right with what you're logging. My lambda error shows over 1000% off. Care to post your scanner setup, so that we can see what you're actually logging and how?

Learn how to setup a WB vs % Error histogram and adjust the MAF off that. If your MAF is pre-BOV, it's going to screw with the data, if post, then it's fine.

For tuning part throttle, I got everything close with an open loop tune and then dialed it in using closed loop. I use a STFT vs MAF setup that is properly filtered via FTC and Commanded AFR to exclude transient data and PE. My LTFTs are completely shut off and have been for months now. My car runs a completely MAF only tune, no dynamic at all, although the VE has been tuned in case the MAF takes a dump.

Things I see in your tune is that unless you know you are running for sure non-ethanol gas, you may want to move your stoich to 14.42 ( E5 ), or 14.11 ( E10 ) and adjust your PE multiplier accordingly, because having the ethanol in the fuel when the stoich isn't set for it is going to constantly throw off the trims and AFR error anyway. Without a very sensitive ethanol tester, it's a crap shoot as to how much you have in there, but unless it's pure gas, there's going to be some.

Is your spark table scaled at all? Since you scaled your injectors, you have to scale every other airflow related table.

[jrsmith]

Thanks for the replies. I do have the proper maf/afr error histogram set up just fine. My current plan is to move my maf from the CAI to just before the throttle body in a 2.5" pipe and then once i've done that i'll continue with my maf calibration. Will 2.5 give me more or less headroom? I understand at some point I may need to get one of those frequency rescalers for my maf once I get too much air flowing.

[AP83]

I ran out of MAF at 5,500 rpm running only 17psi, but then my turbo is larger.

Make sure the MAF is in a straight section of tube far enough away from the TB to get a clean reading. You don't want turbulence from bends or pipe diameter changes.

[cobaltssoverbooster]

running smaller diameter makes the airflow move faster through the maf. this drives the signal hz rate higher which can cause the maf to be exceeded.
if you run a larger say 3" over the 2.5" the airflow moves slower through the maf lowering the signal hz which gives you more room but it will force a re-calibration of the entire maf curve with possible signal clarity issues around idle. the lnf uses a 3" tube iirc properly. you shouldn't have any major issues going to a 3".

[AP83]

To the OP, here's a log I took today to give an example of what and how I log my LSJ-T. Here's my Channels, Chart, and Graph setup.

This is on my closed loop summer tune, DFCO off, AC on. Ethanol is at 31.5% currently.

The car runs E30, so don't be weirded out by the odd Commanded AFR numbers. I tune the car in Lambda anyway.

This was just a spot check on my main cruising MAF cells ( 2700hz to 6700hz ), but it gives an idea what I look at.

Hope it helps, happy to answer any questions.

AP83 Channels.Channels.xmlAP83 Charts.Charts.xmlAP83 Graphs.Graphs.xml7-17-17 PT Hot.hpl

[jrsmith]

Thanks for that AP83...didn't see your last post until recently.

[AP83]

Glad my Scanner setup helped. Just make sure to tailor it to your setup, since mine is very different.

Got a chance to look over your most recent tune.

You need to scale your spark tables a little better. I actually just started with the 2007 Stage 2 tables and scaled from there. It's easier to scale if your Flow Rate Multiplier vs. Volts is 2.0, not 1.3, that way the spark tables can be scaled fairly easily. Here's the guide that I used to get mine setup. Read, understand, and comprehend it before applying it. I hope DSteck doesn't mind me reposting it...

http://injectordynamics.com/wp-conte...SteckScale.pdf

Also, set your stoich to 14.11 instead of 14.68, unless you know FOR SURE that you are running pure gasoline, not E10. You're already introducing an error into the system by leaving it set for 100% gasoline, which most gas today is not.

[jrsmith]

Wow that's like the goddamn holy grail right there! The other info I came across didn't get into details about everything else that gets affected by changing the injector flow rate multiplier...I can't say I completely understand everything but it makes much more sense now, I was wondering about other tables getting "thrown off" and now it's falling into place.

Now a question about redoing the main spark table. I just followed the guide and used the 1.5 multiplier instead of 2. Just went back to the stock tune & took 50% off the MAF & (2) VE tables. For spark, I've taken care of the rows from 0.08 to 0.068g. Now that airmass is reduced by 50% can I just ignore everything above that now? And what about below .08...there's nothing below that so will that lead to some low speed idling issues or something?

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[AP83]

Your table is all wrong.

When I scaled by 50% ( i.e. made my car believe the injectors are 47.5# injectors, not 95# like they are, I halved my MAF and VE, then started with a 2007 Stage 2 table, then copied the 0.16 row to the 0.08 row, the 0.24 row to the 0.12 row, the 0.32 row to the 0.16 row and so on and so forth. That only works if you scale by 50%. You're scaling by 67%. That doesn't directly translate, and you'd have to open up an Excel spreadsheet, do some math, and interpolate.

The scaling amounts have to match. I.E. if you scale the injectors, you have to scale the MAF, VE, and Ignition tables by the same amount or you WILL have problems.

That's why 50% works well, because as you see in the example above, it makes it easy to copy/paste data.

My PE starts at around 0.48g and winds up around 0.96, but the car is moving FAR more air than that, around 50 lb/min.

My highest row on my spark tables is 0.68, everything above that is a duplicate of that row, since 68 is half of 136. You will have to do some hand smoothing and adjusting, and if the low speed idle is a problem, leave the 0.08 row stock and hand smooth it in with the rest.

If you don't fully understand the concept, leave it alone.

[jrsmith]

Thanks, I see I made a mistake regarding the injectors. I've adjusted flow rate vs mult. vs volts to 2. My intention was to scale at 50%

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