mat calculation

[myburb]

I am using a 6395 with BHDF bin and ADVANCED $OE TPS v250.xdf for this. In stock bin the mat is turned off. When that is the case what do they use for that input to the gas law? Standard air temp maybe? Anyone know of a link discussing that. When mat is turned on there is a table to blend with water temp. It looks like a number of 0% means it is full mat with no water and 100% would mean no mat and all water. Am I seeing that correctly? I am installing an aluminum intake and therefore there won't be the constant 195 water in the intake keeping things constant. Looks like gm thinking was heat the intake to a constant and forget mat and we are good to go.

[brian617]

I started a similar thread but never got anywhere... http://www.gearhead-efi.com/Fuel-Inj...7427-OE-OD-etc

[myburb]

Thanks for your link. Looks like it is hard to find any concrete info. From using other systems it is a much used value. In other systems changing mat/iat can change fueling requirements up to 20%.

[brian617]

I went ahead for kicks last week and enabled it in my bin with the CPI blend table, threw my BLMs way off, so its obvious that it has a great deal of effect on fueling. Problem is, which table do adjust for the MAT now being in control of fueling. With my engine warm and idling the CTS was reading 195* and the MAT showed 165* so it was easy to see why it was adding so much fuel. Seems like the has to be a PW vs TEMP table somewhere

[myburb]

My bin has 14 perameters that include mat. Being as mat is unset most perameters are either unset or zero. The one that looks like it would have the most effect is mat / cts blend multiplier vs airflow. Comments. Say useage is related to BPW so now just have to figure what that might mean.