What are the following parameters?

What does transient mean when referring to either diesel timing or fueling? There's a transient button that has timing/fueling values that are separate from the air density values. Just wondering what that is and why is it used.

With regard to air density selections, what determines high to low air density? Is air density determined by the mass in the air density tab? If so, what do the numbers 1-4 correspond to. I'm assuming they correspond to one of the 4 air density selections but how do I know which number is what density?

Is there any value to leaving the post event on? Near as I can tell, the post event is only for emissions.

Transient tables seldomly get used on those trucks and lots of different factors determine whether it will be used or not. And transient is tied to a sub group of engine control called Alpha Determination.

Your barometric sensor is used to determine air density and air density determines which table to use, vast majority of the time it will be the high air density tables. Pretty certain I have a post in some thread on here that states it but 1 is high air density and 4 is low air density.

Post event is used for emissions and much more, like it can be used to help spool up large turbos.

Quote:

---

Originally Posted by Jim P

Transient tables seldomly get used on those trucks and lots of different factors determine whether it will be used or not. And transient is tied to a sub group of engine control called Alpha Determination.

Your barometric sensor is used to determine air density and air density determines which table to use, vast majority of the time it will be the high air density tables. Pretty certain I have a post in some thread on here that states it but 1 is high air density and 4 is low air density.

Post event is used for emissions and much more, like it can be used to help spool up large turbos.

---

So if you were changing timing and fueling in the transient tables, would you just match the MM3 in that table to the density table most likely to be used?

Also, I noticed in the air density table, most of the mass pressures fall in number 4 for the stock file. That would indicate that would be the most used?

For post event, do you most people just leave it as-is or zero it out. Seems pretty useless for me because not concerned about emissions and my turbo is stock.

No, like 99% of the time the truck will only run in number 1, which is the high air density table. It actually takes quite a bit of a drop in air density for it to even switch to number 2, the medium high air density table. The transient tables seldomly get used like I said above. Which tables get used is all conditional based and the conditions for transient seldom ever get met. Your primary table for tuning is the high air density tables, if you want you can just make all the tables and the transient the same so if and big IF it changes tables on you, there won?t be any real change in timing, rail pressure, etc. that?s what most people do and is just fine. You are more likely to see the so called adder tables being used before you?ll ever see it use transient, medium high alt, medium low alt or low alt tables. And don?t be confused about how they are called adder tables in HP Tuners, they don?t add anything, they are conditional use tables just like everything else. If the right conditions are met, they will become the table being used instead of the air density tables.

Thanks for that. One more question. Do most just leave the adder tables as-is? If not, how would the adder tables differ from the hi-density tables?

Your truck from what I see in your signature, I would just leave them as is. For your main timing tables, you will likely never even see any of the 4 adder tables become active. Your pilot timing you will see the coolant temperature correction one become active while the coolant temps are low enough and once coolant temps rise high enough it?ll switch to the high air density table but with just 50hp injectors, you?ll be just fine leaving them as is.

Jim, what does the color shading mean on the tables when you change something. Some turn more red and others green.

Higher or lower than the value in cell from when opened or previously saved if memory serves right.

If you are talking about the color of the buttons to the tables, red means changed from when opened or previously saved, red green appears when comparing to another tune and there?s changes in your tune but don?t match with the compared file and green means the compared file is different and there?s been no changes to your tune.

I was referring to the color heatmap in the table itself. It will be varying shades of green to red to purple. I'm guessing just from playing around with it that, when I increase a number, it turns more red.