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MAT modeling
#1
Hentai Wrote:Starting this because I finally learned somewhat how GM does their MAT modeling.  I know on certain vehicles they bias between the clt and iat sensor depending on a bias table used.

Seems the formula goes IAT+(ECT-IAT)*BIAS=MAT
45+(90-45)*1 =  90
45+(90-45)*.5 = 67.5
45+(90-45)*0 =  45

seems the table is is based on speed on one axis and airflow on the other axis  I have to check again but after seeing in manifold temp slowly creep up even if you have some rpms moving air but you been going slowly around I can see why they have it based off speed as well.

http://redhardsupra.blogspot.com/2008/04...s.html?m=1
Hentai Wrote:more info
http://redhardsupra.blogspot.com/2008/02...t.html?m=1
http://redhardsupra.blogspot.com/2008/01...2.html?m=1

"This temperature accounting discussions brought out few new people:  For example, one dude named Adrian had this simple, but very profound idea.  If MAT=IAT+(ECT-IAT)*BIAS then MAT-IAT=(ECT-IAT)*BIAS, so with a MAT probe we could determine BIAS.  If MAT=IAT, then BIAS=0, which is nice, because not only it satisfies scientific formulas, but also makes common sense.  With an extra temperature probe in the intake (probe part number GM PART # 25036751) we could arrive at BIAS in a very simple way.  Any takers?"

I think if I put my mat sensor in the intake runner it would help show more info and we could come to possibily a usable formula
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