Tuning for Economy

Krazeeun

Krazeeun

Hardway Performance
Joined
Feb 4, 2008
Messages
2,369
Guys

Since switching from a box tuner and using a stock base file, i've noticed my economy, at least according to my overhead has gone down from 17+/- around town to 15+/-

Tuning for all out power at the track was easy, how can I dial in my economy without negatively affecting my drivability?
 
First, don't use the overhead as a gauge.

Please re-read that. It is not a smart-ass comment.
 
I know not to swear by the overhead, and I have been "enjoying" my truck a lot lately with the new toys so I probably won't get the best MPG.

I guess I should reword my original question to "Where should I be changing parameters to increase economy"

More timing? More rail? I need to figure out all the data logging and mapping..
 
For the DMAX you want to raise the rail pressure slightly to smooth out the dips(I don't know what kind of rail pressure the CUMMINS run's, but the DURAMAX seems to like the 55-70 MPA of pressure at cruise), and increase teh timing in your cruise areas, and if it is a VVT drop the boost down to about 1-2 PSI at cruise. Set your throttle tables to be smooth and linear, and make it to reduce fueling spikes. I've also found that smoothing out your pulsewidth changes can help a bit as well. If you want your DIC to read better, simply put more fuel in down low. It won't help your actual milage, but it will make your DIC read higher.
 
Alright I just spent all evening (just ask my wife, she'll tell you..) comparing tunes, smoothing, massaging... etc

ended up with about 2 degrees more timing around "cruising altitude" and as well as 2kpsi more rail around same area.. smoothed everything out and took her for a spin, lie-o-meter is reading closer to what it used to... time will tell on actual MPG, i'll fill up tomorrow and start over
 
every truck Ive messed with we have gaine 2-3 mpg and much better driveability..
 
Krazeeun said:
Guys

Since switching from a box tuner and using a stock base file, i've noticed my economy, at least according to my overhead has gone down from 17+/- around town to 15+/-

Tuning for all out power at the track was easy, how can I dial in my economy without negatively affecting my drivability?
Click to expand...

Main timing in the 1500-2000rpm and 10-45mm3 quadrant...that's your cruising and light throttle zone.

Add timing in that area....and it won't effect spool.
 
What about getting rid of pilot, post injection? (You Just Enter "0" in the pilot/post Quantity/Timing, Right?)

I'm trying to do the same thing, not going for power, just my "cruise to work" tune.
 
apocalypse1812 said:
What about getting rid of pilot, post injection? (You Just Enter "0" in the pilot/post Quantity/Timing, Right?)

I'm trying to do the same thing, not going for power, just my "cruise to work" tune.
Click to expand...

Need to modify both slightly..but you'll get better mpg results from main timing in the "Cruise Zone".
 
Yes a value of "0" will disable that event...but disable in both timing and quantity for the event you wish to turn off.
 
I've heard to just turn off the post injection completely for performance reason's, but unless you've got huge injectors. I haven't heard to mess with pilot?? Just curious why you would shut it off completely?
 
There are many schools of thought for post...I run it on all of my tunes, but its a heavily modified event in both timing and quantity.

Pilot off in certain RPM areas can prove to be beneficial, but turned off in the wrong areas without proper compensation will cause undesirable conditions.
 
I tried shutting pilot off on my LB7, and I HATED IT! I had to turn teh timing up to about 8 degrees and set the idle rail pressure up to 80MPA's just to get it to start up decent, and then it rattled like a son of a gun. I persoanlly don't see any benefit myself to shuting pilot off at lighter throttle levels. I did see a huge loss by shutting it off as my BURB became a lazy smoke bellowing pig. I guess teh CUMMINS is a differrent animal, I wish I had one to play with and see.
 
THEFERMANATOR said:
I tried shutting pilot off on my LB7, and I HATED IT! I had to turn teh timing up to about 8 degrees and set the idle rail pressure up to 80MPA's just to get it to start up decent, and then it rattled like a son of a gun. I persoanlly don't see any benefit myself to shuting pilot off at lighter throttle levels. I did see a huge loss by shutting it off as my BURB became a lazy smoke bellowing pig. I guess teh CUMMINS is a differrent animal, I wish I had one to play with and see.
Click to expand...

Not as different as you would think.

Turn pilot off at the wrong rpm without proper compensation, you'll have a rattle box that's billowing white smoke and won't move.

I worked on a single event tune for close to 3 weeks but went back since I could not get rid of the constant haze at all rpms.
 
So... something along these lines?

ScreenShot2012-01-22at114040AM.png
 
Yeah...until we can see pilot timing were limited on how much to increase timing in that area....

For my personal truck, I have a "island" where I'm running 8* of main and 11-13* pilot in the 1500-2000@25-40mm3 area.

That's netting me 600-650* at 70mph and 18mpg
 
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