MAF Calibration Tutorial

[ms3blackmica]

Originally Posted by NavySVO @ms3blackmica can the 4th gear portion of the cal be done on a dyno? I only ask because: A. I want to dyno the car for numbers, and I can then kill 2 birds with one stone, and B. It aleviates trying to find an area around here where I can open up to that speed while logging, traffic and cops.

of course it can be done a dyno !

[ms3blackmica]

@Pierre Loubser

how did that scalar work out for you ?

[MizzyMS3]

This is great! Thank you for this!

[ms3blackmica]

Originally Posted by MizzyMS3 This is great! Thank you for this!

Not a problem.

If you have any other questions, feel free to ask.

[UnknownSuperhero]

If this was covered before, I apologize. I am looking for a consensus.

1. What is the target # and what is an acceptable #. (for example, anything less than .08 etc. with 0 being ideal.) Also, is there a oh crap moment? (If it is above 10.0 do a maf cal right now kind of thing)
2. Is a + or - number prefered if there are LTFT values.
3. Do you believe revisions are necessary? If so at what interval.
4. If someone is doing a cal, starting with + numbers, next revision they are -, and the third revision they are back in the +, what is the best course of action?


Thanks a bunch in advance. This is a great tool!

[ms3blackmica]

Originally Posted by UnknownSuperhero If this was covered before, I apologize. I am looking for a consensus. 1. What is the target # and what is an acceptable #. (for example, anything less than .08 etc. with 0 being ideal.) Also, is there a oh crap moment? (If it is above 10.0 do a maf cal right now kind of thing) 2. Is a + or - number prefered if there are LTFT values. 3. Do you believe revisions are necessary? If so at what interval. 4. If someone is doing a cal, starting with + numbers, next revision they are -, and the third revision they are back in the +, what is the best course of action? Thanks a bunch in advance. This is a great tool!

1. I am usually happy if the LTFT's are within 3-4%. 3-4% seems to be a good number between cold and warm weather changes. Although trims up to 6% aren't really an issue either. 10% really isnt an "OH CRAP" moment. My fuel trims will go to +10% when i put the AC on. This is normal. I'd say anything in the 20% range is an "oh shit i need to do a maf cal now" type of moment.

2. They can be + or - (absolute value). The ECU will either be pulling fuel out (-) or adding fuel in (+). As long as your within + or - 3%, you have a good maf calibration.

3. What exactly do you mean? It usually takes a couple revisions until your MAF cal is nice and tight. If you add any intake flow mods, you will have to revise.

4. This can happen a lot. For example, someone might have a 4.7% LTFT. Then they take 4.7% out, and now they have a LTFT of -3.9%. And then they try to add 3.9% and the same thing happens. This is usually the cause of not putting enough miles on the car before taking a maf cal log. Also some people like to only add as much as they need..For example, if your LTFT is +4.7%, some people might add only 4% to the maf breakpoint in order to bring the LTFT's around 0.7%. That is another way of going about it. Takes some time and practice. Also make sure you have no leaks.

[phate]

Originally Posted by UnknownSuperhero If this was covered before, I apologize. I am looking for a consensus. 1. What is the target # and what is an acceptable #. (for example, anything less than .08 etc. with 0 being ideal.) Also, is there a oh crap moment? (If it is above 10.0 do a maf cal right now kind of thing) 2. Is a + or - number prefered if there are LTFT values. 3. Do you believe revisions are necessary? If so at what interval. 4. If someone is doing a cal, starting with + numbers, next revision they are -, and the third revision they are back in the +, what is the best course of action? Thanks a bunch in advance. This is a great tool!

Target trim is 0%, you are correcting towards this value, based on the latest learned trims. Trims will change throughout the year, so I don't worry for anything less than 6 or 8%. If I see trims beyond those (after a good Cal), I know there are other issues (leaks).

Negative is probably preferred for the closed to open loop transition range. The thinking is the car will be biased rich as it transitions, thus being safer. It doesn't exactly work this way, but whatev, it's a good sentiment haha.

Revisions are usually only necessary when hard parts change. I tend to leave them as is so I can identify significant variances caused by other issues. Again, 1 proper Cal is typically all it takes. [If you dick with vtcs or repair issues, this may not be true].

If you're doing a MAF Cal right, you won't have revisions with significant variance after. If you see big swings, you're likely trying to tune around a leak.

[CWP_MS3]

Discuss Here: http://www.mazdaspeedforum.org/forum/foru...torial-121334/