I too am at the point to where I am trying to tune for the best mileage (pretty much like the rest of my tune). So if I follow this discussion correctly, best mileage is done by increasing main to around 8* (which I have done) and decreasing pilot to around 10*? This will drastically decrease dwell time over stock as the pilot is at over 20* (IIRC). Outside of the cruising range, the pilot is significantly retarded and pilot advanced, increasing dwell time significantly. What are the advantages and disadvantages of changing the dwell time and pilot mm3?
Max cruise timing
- Thread starter arinkuddy
- Start date
Ghostman
24v crazy
I was running down the highway the other day at 75mph. With a pilot tune my total us of duration adding the main and pilot together was around 750. When I turned to the single event tune my us duration dropped to around 600. Just stating what I saw.
Sent from my iPhone using Tapatalk
Sent from my iPhone using Tapatalk
Running 8* of main timing and 10* of pilot seems to have gained a mile per gallon compared to 8* of main with stock pilot. VERY early testing but this seems to had positive results. I'm gonna continue with this tune for a while and maybe try 10* of main also.
Sent from my SM-G920V using Tapatalk
Sent from my SM-G920V using Tapatalk
arinkuddy
New member
I've been running this which my truck seems to like
I cruise in the 40-45mm3 range on level road so im pretty much running about 8.5* of timing there. I think 10* is getting a bit high for the 45mm3 cell.
I dont have enough data to say for sure but looks promising.
I can say this table did not yield as high MPG
Also IDK if many of you guys use this feature but use the "load alternative calibration for comparison" and open the unmodified tune you are using. Then you can go back and forth between stock and yours, and it also normalizes the scaling so which can be nice.
I cruise in the 40-45mm3 range on level road so im pretty much running about 8.5* of timing there. I think 10* is getting a bit high for the 45mm3 cell.
I dont have enough data to say for sure but looks promising.
I can say this table did not yield as high MPG
Also IDK if many of you guys use this feature but use the "load alternative calibration for comparison" and open the unmodified tune you are using. Then you can go back and forth between stock and yours, and it also normalizes the scaling so which can be nice.
Ghostman
24v crazy
I've logged some straight highway miles driving from Texas to Colorado. On the single event tune best I got was 18.9 mpg. Got 16.8 on two other tanks. Probably due to 80+ mph speeds. All hand calculated. Stock suspension with 32-33" tires. Seems there is room for improvement.
Sent from my iPhone using Tapatalk
Sent from my iPhone using Tapatalk
Ghostman
24v crazy
Ghostman
24v crazy
I'm on my way back so I tried a different tune. It's same as my single event tune except it's a pre/main injection tune and the timing tables are stock. Mileage dropped to 14.6mpg. So timing definitely makes a difference and definitely better than stock timing.
Sent from my iPhone using Tapatalk
Sent from my iPhone using Tapatalk
tylerltr450
Wanna Be Hacker
Keep up the good work trail and error are the only ways!!
I would say try to get a millage tune on a 2 setup injection tune.
I would say try to get a millage tune on a 2 setup injection tune.
Ghostman
24v crazy
I want to it's just so much harder to know where to start compared to just working on only a main tune.
Sent from my iPhone using Tapatalk
malibu795
2wd numb nut
Basics being same... I run 20,000psi rail while cruising. Higher psi equals better atomization, and less injector on time and better throttle response..
As you still need X volume of fuel to generate Y HP.
Pilot timing I haven't messed with much.. Main timing I don't go past 1* per 100uS, regardless of rail psi, while cruising..
I find it rattles more especially in colder temps when there is more then 1* per 100uS timing on stock injectors
Alot of it is trial and error since max effort or close to it are different between engines
As you still need X volume of fuel to generate Y HP.
Pilot timing I haven't messed with much.. Main timing I don't go past 1* per 100uS, regardless of rail psi, while cruising..
I find it rattles more especially in colder temps when there is more then 1* per 100uS timing on stock injectors
Alot of it is trial and error since max effort or close to it are different between engines
Last edited:
Leiffi
New member
Have you ever heard about fuel penetretion ? Too much pressure penetrates too much at low boost and rpm and that means fuel dont mix well with air and might touch cylinder walls and wash oil out of them. I wouldnt change factory pressure vs boost/rpm, they have studied it with better equipment than any of you have.
arinkuddy
New member
I am running 10deg of pilot time and 2mm3 pilot qty both across the board except idle where i have it stock.
Idk what to think about mileage anymore... there is just so many variables. Dropping timing below stock in cruise area does hurt it for me but raising it much doesn't yield much gains.
I remember running my smarty jr and on timing 4 I got the best, too bad i couldnt peek at what they were running.
arinkuddy
New member
I agree, I wouldn't dare run that high of pressure cruising. I actually use slightly lower than stock cruise pressure where it spikes a little around 45mm3. I actually was theorizing that the extra hp used by the cp3 to get that pressure may cause diminishing returns anyway.
I wondered how the old 12 valves got such good mileage with the lower pressure and im assuming wider pulse. Less parasitic losses from injection system? No pilot?
arinkuddy
New member
running higher pressure always caused a surge in cruise for me and an annoyingly touchy throttle.
arinkuddy
New member
no not really talking about the tables i posted above im talking about dropping the cruise area down to like 5 deg. That seemed to hurt mileage. Where do you cruise? like 1800 rpm 40-45ish mm3?
malibu795
2wd numb nut
On the dmax there are about 8-10 main tables that have to "jive" to get smooth respone on a general tune.
Moving rail pressure in sooner throws throttle, timing, Mm3, boost all off the normal operating area of the charts and they all have to be adjusted to get smooth operations again
Empty I run less then 20% throttle, realy touchy for most, Loaded I'm 25-40% throttle
Stock setup ID be 35-45 Empty loaded be 60-75% for same fueling...
I've got my dmax setup I can go full fuel by 1800rpm with timing adjusted for throttle and RPM, as full timing at 1800 that I run at 3000 would hurt the engine..