MAT Correction

[mtlcafan79]

How does the MS2/extra code calculate pulsewidth based on intake temp? I got stuck in traffic last night and noticed I was idling higher and higher until the point where I was into the 15's AFR wise. Under hood temps were up to about 120-130*. I don't use ego correction at idle.

I looked at my MAT correction values and they were all zeroed out so I thought that MS wouldn't change the PW based on temp since the values were all zero. I noticed varying MAT temps with my stim that the pulsewidth does change PW based on change in temp. Using my stim and adjusting the MAT correction values at each set temp I was able to keep a fairly constant PW across the temp range. I had to set the corrections to nearly 25% at the higher temps to get the PW back to normal. Does that sound right? I will have to let things warm up under the hood to adjust AFR's for each temp, but I can tell already that things are behaving much better.

[md95]

As far as I know, the air temp correction factor is the same as MS2 standard, and MS1/Extra. I think you have found the same issues i had with MS1 Extra, where the air density correction factor was too agressive as MAT increased, pulling out too much fuel. This is why we have the MAT correction table in MS2 Extra, to compensate for this, and to make our own custom correction curve, on top of the standard air temp correction factor. The table doesn't replace the air density correction factor, it just works with it. This lets us do, exactly as you have done, by adding in fuel as MAT has increased, to keep PW in check.

[muythaibxr]

md95 is correct.

Ken

[mtlcafan79]

OK. I just found it odd that it required that much fuel to correct.