What makes an Economy tune?
 

Is it increased SOI, ICP, decreased PW, or all of them, and how much?

I would assume lower shift points, earlier TCC engagement, and a "softer" low boost fuel map but I am just shooting in the dark here.

Shooting into the dark and just about hitting a bull's eye. How's that for lucky?

Very little on all accounts of SOI and ICP. PW can be whatever you want once you get above a certain ICP since you don't really care about economy once you get above 2000 PSI or so.

I would increase SOI a degree or two at the most below 1600 or 1800 RPM and at low fuel rates. ICP can ramp up a little more aggressively but again, you're trying to go for economy.

All in all it boils down to your right foot. THAT'S it.

Ok.......well its pretty hard to control the right foot sometimes, but if I had a tune that could do it for me that would be pretty nice.

Would lowering the entire Mass Fuel map do this?

So by increasing ICP and lowering PW you will not gain any MPG results, thinking better atomization?

The SOI increase I understand but it is kinda weird to think about everything all at once, (this affects that, and that changes that):crazy:.

I love it:cheesy smile:

Well in all actuality, commanding an increase in ICP does have an indirect "advancing" property to it as well.

As far as lowering the entire MFD map......yes and no.

You can lower the values enough to give a dead pedal.

Another idea would be to lower the fuel limit for RPM map and set the low boost fuel map to give the desired result and still be drivable. It's a balancing act.

I'd just put an egg on the accelerator pedal. :notallthere:

And the plot thickens:)

Would just increasing the ICP be enough to get better MPG's, or should it be accompanied with a slight increase in SOI?

I understand lowering the fuel limit stuff, but trying to understand how to make the engine more efficient on its own, without my negative influence.

The egg might not be a bad idea tho......:hehe:

Grrr....damn touch screen, gotta be careful around these things.

Just increasing the Desired ICP table does little. It's a function of MFD and RPM. So.....

What I said before about a balancing act with the MFD map becomes a little more clear.

Yes, the Desired ICP map can be increased in those areas where you wish for a little more efficiency. Before you get too excited about asking for 1500 PSI where there was previously 700, there will be a point where it becomes a bear to drive; we don't want that. Also the benefits will start to diminish at some point.

On a side note, those ICP-fooling devices like the Workhorse module and Edge Juice actually DO work. They command an increase in ICP and mileage does go up. They wreak havoc on the HPOP, but they do give you a decent power increase with some mileage if driven decently.

:cool_beans:

Ok... I think I understand now.:)

What negative effect would there be with having too high of ICP, touchy pedal, increased engine noise, too much fuel too soon?

What problems did those modules cause on the HPOP's? (1211?)

Noise, roughness, and jumps in pressure can cause a touchy or jerky accelerator pedal. Besides, I think that certain MFD becomes inefficient at certain ICP values. I can't say for sure, it's just my opinion.

Yeah, the P1211 codes were a side effect. Actually, the HPOP was forced to work harder ALL THE TIME. With most aftermarket tuning, the ICP is actually virtually unchanged. So when driving normally, the HPOP isn't working harder than stock.

I guess to say its a balancing act would be an understatement..........well at least to me. Guess it just comes down to experimenting, to see what works for me. Just wish it wasn't so damn cold here!

Thanks Cody

This is why I need a 20 position chip... I was trying to shorten the PW and raise the ICP by the opposite amount. IE lower PW 10% and up ICP 10% thinking less fuel but better atomization...

I am wondering how advanced of the SOI would be safe at my altitude. wondering if there is a guideline like 1 degree per 1000 feet elevation for example. Now Cody is suggesting the SOI is not a big influence on economy right? I'm trying to get a good fwy econo tune thus I am working in the 1700-2200 rpm range with my mods. Cody, Do you think pulling the MFD down on the low end of the APP would have a bigger effect? the downside is that would affect the whole RPM range at that APP

Dave, say hi to Santa for me and tell him I been a good boy(lie) being you live in the same town as him

As far as safe SOI goes......:whistle1: . There is no magic number. Without retyping everything I typed in the SOI thread, I will just say that there are
far too many variables to put a number on it.

I didn't suggest that SOI wasn't a big influence in economy....only that there are far more adjustments that can be made on top of SOI to help increase efficiency.

Pulling MFD down will do nothing for economy except slow your acceleration for any given physical accelerator pedal position. If you want to accelerate at a given rate, you will be injecting a similar amount of fuel whether or not you're at 20% APP in one program or 30% in another program with a less sensitive pedal. Besides, once you start really screwing with the MFD map, your shift points get out of whack and then you need to adjust them again (remember how shift speeds are based halfway on APP).

:thumbs up yellow:

:rofl: :rofl: :rofl: Will do, next time I get outside of the igloo to go and feed my penguins. Just gotta watch out for those polar bears! :smiley_roll1:

I too was thinking about making adjustments like this, but I didn't think that the changes would be proportional.

Cody, do you feel like this would be a accurate way to increase ICP, or is there "a rule of thumb" :doh:when raising/ lowering ICP?

Got a joke for you,
Why don't Polar bears eat Penguins?????


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Cuz Penguins only live on the South Pole and Polar Bear's on the North...

Why dont people know that? You would be amazed at the questions people ask.......

Just like those eco-nazi terrorists that think that cows fart and want to pass legislation to tax them.......



Cows CAN'T fart.

:doh:

DJ...

The thing to remember about the ICP/PW relationship is that the pulsewidth is already based partly off of ICP. So technically, if you raised the ICP then the pulsewidth should drop automatically. You shouldn't have to go in and make any further changes. Unless I change the injectors, the main pulsewidth table doesn't get touched. It's all handled elsewhere.

Cody...

Cow farts. That's funny right there, I don't care who ya are!

Oh, ok ya mean something that actually makes sense.... I was just messing with the 80HP trying to make it more economical on the freeway. I pulled down the Low boost fuel in the cruising RPMs progressively about 10-15% at less than 10PSI down to zero. haven't tried it yet... would I need to change anything else to compensate for the lower amount of fuel with that amount of change... maybe it won't run at all.. who knows but I'm on vacation so I got time to play around a bit Plus I'm at sea level for a change:woot:

It'll run, but the biggest thing you'll notice is that the truck will seem a little slugish on acceleration. We've been there and done that and that's why we don't offer Fuel Sipper anymore. To many complaints that it just didn't pull well off the line at light to moderate throttle. Of course, heavy throttle worked nicely but then what's the point of the program?

You'll find something that's going to work for you. Things that have always helped me with economy:

Shifting (lower the shift points)
ICP (up 5% to 15%)
SOI (up 2 to 6 degrees)

Hope this helps.

Great, thanks,
I am looking for a really economical freeway program 1100 miles one way, shifting doesn't really become an issue. Ill bump the SOI and ICP up a little and see what happens :crazy:
Actually 90% of the time I am very light on the throttle, but if I need it to, putting my foot into it I want it to move.. so that actually would work well for me....

Would it be better to add the SOI using the SOI delay map, or SOI map?

How about for altitude?

And how many feet above sea level counts as high altitude?

DJ,

Make sure you are not significantly modifying BOTH the SOI Main and SOI Offset tables. They compound each other and can easily result in SOI values well over 45º. For reference, stock is about 24º at full throttle at around 3000 RPM.

Dave,

Since the SOI is handled in degrees on the SOI Main table, this is easier to translate. The SOI Offset (Delay) is much more vague, but is also more useful in the respect that you can control the temperature at which timing is added. This prevents one from running too much timing when the engine is cold and possibly causing damage. You could also use the SOI Adder vs. ECT, but this lacks a bit of resolution as it is only 7x7 to start with and 3 cells are wasted below 800 RPM.

I didn't touch the SOI offset as it seemed to vague cuz it would modify the whole map rather than specific areas, right? hadn't though about the SOI and ICP vs temp, Nice being in CA is that its easier to test out tunes due to the mild weather....

I was doing some figuring on milliseconds vs degrees and rpm... is this right
@600rpm= 10revs/second = 1rev/ 0.100 seconds or 100 milliseconds this 100/360 degrees = 3.6 degrees of rotation per millisecond at 600rpm or 7.2 degrees of rotation at 1200rpm ...10.8deg/millisecond at 1800 rpm and so on...
so for example at 1200 rpm an injector pulse width of 2ms would inject diesel through 21.6 degrees of rotation ???????

definitely doin' too much thinkin' 2nite...:whistle1:

Is there a constant for the burn rate of diesel... or I guess it would be on a slope variable to temp hence the reason for the offset for cold temps???:crazy:

See if this calculator helps...

Also, I think you boo-boo'd your calculation. I think you meant 21.6º of rotation at 1800 RPM and 2 ms. In any event, the rest of your math is correct.

yep we will call that a typo...:smiley_roll1: ok thanks for the chart too:2thumbs:

I like the idea of using the SOI delay map to add timing, but what makes this map so complicated(ms instead of deg).? Can I get a Clif Note version?

The reason the map is so complicated isn't because of the time value in the table but the fact that time is fixed and engine speed varies. That means that the actual SOI degree variance increases as the RPMs increase.

For example:

At 1500 RPM, the crankshaft will rotate 9 degrees per millisecond.
At 2600 RPM, the crankshaft will rotate 15.6 degrees per millisecond.

Using the same RPM values and a similar delay value will give you a difference in overall SOI advance difference of 6.6 degrees at 1ms and it goes up with more delay as long as all the other SOI adders and maps stay the same. For example, if the delay is doubled to 2ms, the actual SOI advance doubles as well to 13.2 degrees.

I hope this makes sense....

Ahh...I see..... does seem like things could get a little hairy.....quick!




Hmm....

Especially when building files for high RPM racing/pulling applications. A small change in the SOI Offset could end up being a large timing change at 4000 RPM.

But your fuel still burns at a constant rate.. haven't found the numerical constant for that but you can't get the fuel to burn faster so burn rate vs milliseconds should be a constant... (unless you add or remove something like NOS or elevation less O)
EDIT: Life should be so simple.. wrong again see next post:doh:

The thing is, the fuel DOESN'T burn at a constant rate. Changes in RPM, Boost, Ambient Temp, Fuel Temp, ICP, and others all change the burn rate of the fuel because the temperature of the compressed air and injected fuel all change. Even just a simple increase in ICP will change when and how rapidly the fuel will burn.

Sheesh, I was thinking that all along there was a 1 constant something in all this.. WAIT! I know it what it is. the one thing that is constant is that nothing is constant!!!!:smiley_roll1:

well in any case it finally looks like my MPG mods are making some improvement if My lie-o-meter has anything to say about it....
I am using the 80HP to build some MPG tunes, would there be a better base map to build from. I made the changes u mentioned earlier in the thread... I am really concentrating on the low boost, low APP area for running on the freeway as I like the get up an go on the 80 off the line. it has not seemed to affect that part of it thus far which is good...