How To: Closed Loop MAF Scaling

subarutech77 · **Joined:** Fri Jul 17, 2009 2:47 am **Posts:** 77

Here are the screenshots- for some reason they come out 5 pixels too tall to upload

Oh yeah, its an 05 FXT AT

thorne · **Posted:** Wed Nov 25, 2009 7:52 pm

Why not force the car into CL and sample a bunch of load settings and use the lc-1 vs the stock 02 and make corrections as such rinse repeat?

watchunglava · **Posted:** Tue Mar 16, 2010 8:30 am

can i change the values in collum m of the graph data tab, as my maf has different values listed, ?

watchunglava · **Posted:** Tue Mar 16, 2010 8:39 am

here is what mine looks like

1.91
1.95
1.99
2.03
2.07
2.11
2.15
2.19
2.28
2.38
2.48
2.3565
2.54537
2.75847
3.18313
3.2864
3.58026
4.01085
4.16
4.49129
5.12606
5.77674
7.21978
8.77579
10.3879
12.058
13.8358
15.7838
18.9126
20.1161
22.6936
25.539
28.7444
32.4146
36.5778
42.3981
49.0428
57.5361
69.9812
81.8414
85.5512
103.636
118.226
137.105
170.578
206.506
255.496
349.144

watchunglava · **Posted:** Tue Mar 16, 2010 8:41 am

also why would i use af #1 and not my wideband?

wrxsti-l · **Posted:** Thu Mar 18, 2010 10:16 am

watchunglava wrote:

also why would i use af #1 and not my wideband?

Because your ECU uses the data aquired from your A/F sensor in closed loop

watchunglava · **Posted:** Thu Mar 18, 2010 4:12 pm

wrxsti-l wrote:

watchunglava wrote:

also why would i use af #1 and not my wideband?

Because your ECU uses the data aquired from your A/F sensor in closed loop

true, what about changing the maf values?

wrxsti-l · **Posted:** Fri Mar 19, 2010 1:08 pm

watchunglava wrote:

wrxsti-l wrote:

watchunglava wrote:

also why would i use af #1 and not my wideband?

Because your ECU uses the data aquired from your A/F sensor in closed loop

true, what about changing the maf values?

What do you mean?

watchunglava · **Posted:** Fri Mar 19, 2010 3:37 pm

What do you mean?[/quote]

on the spreadsheet, the values listed are not the values i have in my maf scaling .

wrxsti-l · **Posted:** Sat Mar 20, 2010 7:34 am

You have to change the g/s values for the voltages that match your MAF scaling table by the pecent suggested in the spreadsheet.

watchunglava · **Posted:** Sat Mar 20, 2010 8:32 am

wrxsti-l wrote:

You have to change the g/s values for the voltages that match your MAF scaling table by the pecent suggested in the spreadsheet.

no doubt. but in the spreadsheet there are different maf values allready in place, should i change them to whats on my rom now right?

suebaroo · **Joined:** Wed May 12, 2010 5:38 am **Posts:** 60

IN the bolded/italicized line, wouldn't i be speeding for 30 minutes? So if i stay at 65mph, that would be around where i'd "switch to OL" correct?

wrxsti-l wrote:

[*]RECORD AT LEAST 30 minutes of highway/freeway driving in your top gear as close to the point where you switch from closed loop to open loop - you can see when you switch from closed loop to open loop as the "CL/OL Fueling" value will change from "8" to "10". A highway/freeway with a long, constant incline is best - this will allow you to gather data points for the upper most region of the closed loop section of your MAF Sensor Scaling table (MAFv of around 2.8v).
[*]RECORD AT LEAST 30 minutes of general driving. This can include driving to/from shops, movies, work etc.
[*]RECORD AT LEAST 15 minutes of slow speed driving - around an unpopulated car park is best
[*]RECORD AT LEAST 5 minutes while you idle - BUT not while your car warms up. It is best to do this after you have done all the other driving above, as your car will be at running temp and the engine bay will be heatsoaked.
[*]And as per the first point, NO SUDDEN THROTTLE CHANGES. If you need to stop, slowdown, speed up quickly - click the "Log to file" button first, to stop logging. Then when you are back at correct speed, click it again to start a new log. If you continue to log data while you stop, start, speed up, slow down, with constant sudden throttle changes, the data collected can skew the results and your MAF scaling can be dramatically out for any MAFv where these sudden throttle changes occurred.[/list]

wrxsti-l · **Posted:** Wed Jun 02, 2010 11:13 am

depends on the gradient of the road you are drivig on. Traveling up a gentle hill/gradient at road legal speeds can get you to the edge of CL/OL without much effort. You just need to find a freeway that has a long constant gradient

suebaroo · **Joined:** Wed May 12, 2010 5:38 am **Posts:** 60

I just wanted to add that if you're logging for idle, make sure your computer ins not plugged into the cigarette lighter because the power adaptor will make the MAF V read all wrong.

Gonads · **Posted:** Sat Oct 23, 2010 10:41 am

Hey Leslie,

I've fitted a home-made 86mm in-guard CAI setup (check my thread on Rexnet). I rescaled the MAF map by the increase in cross-sectional area and kicked it in the guts. After doing some logging of closed-loop corrections, it seems that everything is hovering around a -12.5% correction. Would I be right in assuming that areas of the scaling map outside of what can be picked up under closed-loop conditions are probably something like 12.5% out as well? I'm just thinking that I should multiply all the airflow numbers by 0.875 and go and start logging again. What do you reckon?

I asked the question on NASIOC as well, just thought I'd post up here as it's probably the right place.

Advice greatly appreciated.

...Ben

RomRaider

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How To: Closed Loop MAF Scaling

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