A few 5.3L DoD tuning questions.

[06black]

Gents,

So I started to tune a friends 2007 silverado with the 4spd auto and 5.3 w/DoD but the naming of a few of the tables have me confused.

are the vacuum tables not linked to the MAP sensor? example, the disable vacuum is 3kpa?? So it enables at 30-40 KPa, but disables are 3KPa....so almost a perfect vacuum?

I found a post by Mr. Ross Kemp stating that the tables are only based vacuum and not actual absolute pressure. So Baro - MAP should return the value this table is looking at?

the other table that Im interested in is TPS delta. judging by the description of that value, its a percentage (OE is 50%) of 12.5ms??
Any more details on how this works would be great!


My thought is to set the TPS max over 59% (the max value the TPS will hit in V4 mode) and set the disable vac to 0kpa, and use just the TPS delta limit to change the truck in and out of V4 mode.

this way it will hold in v4 on the highway (65-70mph on the flats) and if I make a big enough TPS request change, it will jump back into v8 mode. Id rather it slow down a bit over some elevation changes then change back to v8 mode and blow the MPG out the window.

[Area47]

did you get the tire size crap fixed?

[06black]

yup. everything works but the software documentation I have doesnt mesh well with what I see in HPT for table values / reference.

so, Im here now.

[eficalibrator]

3kPa of Vacuum is not the same as 3kPa of MAP.

Vacuum is the difference between Baro (~100kPa at sea level) and your current MAP. So if your MAP reads 80kPa, then you currently have 20kPa of Vacuum. Going below 3kPa of Vacuum, basically means you are WOT.

[06black]

So Baro-MAP was correct. ok, thats good to know.

The TPS delta is the only unanswered question.

[Rally1969]

Did you get that figured out? I was also wondering about the DoD adjustment many ask to turn it off and yours was the only post that I see for turning it up to gain better mileage. I was however wondering what long term effect that may have on the Engine.
Any thoughts?

[MMGT1]

DoD shuts fuel and spark off so essentially you have turned those cylinders into an air pump. There has to be a break point though where shutting them down too early will actually cost you more as the 4 cylinders just cannot keep the weight of the vehicle moving. What I am saying is, you overwork the DoD and I can see it costing more fuel than if you were to lower it again. If you were to use a MPG calculator and some "in the field" testing you should be able to find the sweet spot where the DoD effectively nets the best MPG possible

[superstealthcc]

Gents,

So I started to tune a friends 2007 silverado with the 4spd auto and 5.3 w/DoD but the naming of a few of the tables have me confused.

are the vacuum tables not linked to the MAP sensor? example, the disable vacuum is 3kpa?? So it enables at 30-40 KPa, but disables are 3KPa....so almost a perfect vacuum?

I found a post by Mr. Ross Kemp stating that the tables are only based vacuum and not actual absolute pressure. So Baro - MAP should return the value this table is looking at?

the other table that Im interested in is TPS delta. judging by the description of that value, its a percentage (OE is 50%) of 12.5ms??
Any more details on how this works would be great!


My thought is to set the TPS max over 59% (the max value the TPS will hit in V4 mode) and set the disable vac to 0kpa, and use just the TPS delta limit to change the truck in and out of V4 mode.

this way it will hold in v4 on the highway (65-70mph on the flats) and if I make a big enough TPS request change, it will jump back into v8 mode. Id rather it slow down a bit over some elevation changes then change back to v8 mode and blow the MPG out the window.

[dadejack]

@06Black How did this work out for you?