Economy Tune for a 8500-9000 Truck w/ 75HP Inj

[KRob]

Team, 

 

I have a 3500 miles drive starting tomorrow...thanks Covid normally I would have flown...I am doing a surprise inspection and check in on several facilities I manage.  Starting South of Seattle tomorrow and probably going as East as Denver and then back through SLC and into CA and then back up to home.  

 

My truck is an 01 HO (6 speed) with a SO pump and 75 HP injectors and 3.55.  It weighs some where in the neighbor hood empty 8500lbs maybe up to 9K.  

 

I am hoping for some guidance on building a tune over the next ten days for economy.  Currently I am lucky to get 14mpg (i end up with trailer regularly so that may not be accurate for empty).  Figure i'll set cruise at 70-75 mph and go from there.  Fueling i believe I understand fairly decently but the timing is what scares me, probably because i don't understand it well.

 

Any suggestions on where to start on the timing end.  My tuner (Android tablet) is out in the truck otherwise id go pull it and rattle off what i currently use every day which i think i have set more for always having a load.  

 

Any thoughts or advice would be appreciated.  Or specific parts of the 41 page tunning guide which i have skimmed some of.  

 

Thanks again Rob

Edited May 4, 2020 by KRob

[Me78569]

generic rule of thumb is to keep timing in the 19-20* range for cruise timing.   70-75 mph is going to suck fuel though.  

 

this is generically a good starting place for timing.
 

Fuel Load Timing: 2

Low PSI Timing Reduct: 2

Timing Reduct Scaling: 100

Light Throttle Timing Adv:2

Light Throttle Timing Load Limit: 30

 

Timing vs rpm

1500: 16

2000: 18

2500: 25

3000: 28

Timing Max: 30

 

 

 

[KRob]

Thanks ME.  Ill start with that and start running.  

[Me78569]

light throttle limit is the variable that tells the quad when it should be using mpg timing or towing timing.  

 

at %30 it means that when load at under %30 you get mpg timing ( base timing + light throttle timing)  but if load increases above %30 then you get performance timing.  That light throttle limit should be ~%5 above your typical cruise load.   you want the quad to jump out of mpg timing if you encounter a hill or something.  or if you push the pedal down to pass.