i thought about this on the way home from work today. once the maf is maxed most of us tune based on just RPM. there are a couple of problems with this. one is there is no compensation if you decide to crank up the boost, the other is if the DA changes you will go leaner or richer.

my idea wont help with changing boost but i have an idea for changing DA. what makes the most diference in DA? i always thought is was temperature.

if it is mainly temperature couldn't we use the PE vs temp to add or pull fuel based on IAT temps? that table looks at coolant temps so the first thing we would have to do is get an extra coolant sensor and hook it into the intake tubing. then hook up some kind of relay so when you went WOT or maybe a hobbs switch it would switch from the actual coolant temp sensor over to the new one you just put into the intake. then use the PE vs temp table to add fuel when it gets colder.

i know barometric presure and humidty and maybe some other things go into DA and changing fueling. geting a corection factor based on temp would have to help. would it be worth it?

 

i think the only problem with that is that a lot of coolant temp sensors have to be in the liquid to read correctly

 

if that is true maybe the IAT temp sensor has the same voltage vs temp scaling and it could be used.

 

I just checked out weatherunderground.com, and couldn't find where humidity changes would swing the DA of a certain temperature more than about 300 feet. 300 feet DA is only like 1 percent or so change in airflow. So it might be accurate enough.

Does the altitude change much where you live? Where I live, I can drive 15 minutes from my house and be up to 3000 feet higher or lower. So something like this wouldn't work for me.

 

+-200feet at the most here. it is prety flat.

 

Wouldn't the temp of your intercooler water change things up a little?

Say intake air stays the same temp, but on one run your intercooler water is hotter than another. Wouldn't that cause the post intercooler air to be less dense and you'd go rich?

 

i am not sure how all that works, seems to me the best place for the sensor would be post intercooler just like the IAT sensor. i want to know the actual temp of the air going into the motor, not so much the outside temp.

i want more oponions on this. i dont even know how much of a problem i have now without any corection since i haven't ran it when it was all that cold out. maybe there is no problem. i adjusted my fueling on a 60deg day and never really looked at it since because it has never really been colder than that.