So while Mike is happy with the power of the quad he is struggling to get good mpg out of the unit, unlike Tyler and myself.  Bothersome because we didn't even have to try it just came with the lack of smoke.

 

I think Tyler did 21 on his first try with his firehouse injectors and I did 24.7 without trying with my 100's

 

Mike however is struggling to hit 20.

 

We are all running the same timing map, but different tuning on the canbus fueling.

 

I am however down at nearly sea level now running Mike's tune and I am smoke free so I know Mike's tune is WAY under fueled since he has 50's.  I am betting Mike has get away with a starting point of 98 or even 100 rather than the 93 he has with his current tune.

 

Watching the timing number I can see what I get high timing at high revs and low throttle / load.  

 

At 1500 rpm 55 mph and flat ground low tps you can easily see 22 or 23*  as soon as you increase throttle to 25-30% timing drops like a rock to 14-16*.

 

Once revs get up above 2200 then timing starts getting high again.

 

 

So what makes for good mpg, I have never bothered to look or research but I am assuming we are dealing with timing advancement before TDC?  Am I off on this thinking?

 

My current thinking is since Mike is under fueled due to the low canbus tuning he is having to us significantly more tps which is dropping the timing.

 

 

So any thoughts on this?  I am assuming that Mike's issue is the under fueled tune causing him to need higher tps at cruising causing the oem map to retard.

 

 

8 hours ago, Mopar1973Man said:

I would have to say that is more likely due to less rolling resistance and the rotational mass is maybe down just a few pounds per tire.

Less mass and better highway tread means less tps to keep moving, you would be surpised how fast timing drops off with just a few % tps increase over 22 or 23

 

Last fill for me was 15.56 mpg which isn't bad at all considering we were driving in glacier national park all day.  Very steep and 25/35 mph speed limits, stop and go.

 

 

I have been mulling over the timing stuff.    I am going to change the timing map to use load rather than boost.  So it will be load vs rpm.  This will allow me to create an island for a few more % of timing at cruise.  I still don't know how to allow for "custom" timing like we do canbus.

 

Just in the quick tune I created for my truck I'm back to 22 MPG (Uncalibrated) on the OBDLink. So far this is the best number so far I've seen from the Quadzilla. Like on my way home tonight from work I passed one semi-truck and it pulled like a scalded ape. Excellent power. As of the OBDLink it a rule of thumb for now till I can get through the calibration process.

Curious to see what you hand calculate.

 

 

Any smoke off idle starting at 100?  Or is smoke only in wiretap range?

 

 

Modified to 1-5 positions to 105%. No smoke really launching and driving normally. Since my last tank is a fill I can math out a number to verify. Also I got hired by "4 Elements Waterproofing". So I'll be driving back and forth to Homedale, ID to do a high school roof so I'll get plenty of time to check out the tune and how it does. I'll be doing rubber roof coating on a high school.

Good to hear that you are still smoke free starting at 100.  I really under shot your first tunes lol.

 

 

1 minute ago, Me78569 said:

Good to hear that you are still smoke free starting at 100.  I really under shot your first tunes lol.

 

 

I think you were too used to playing with the firehose injectors  

Hey my starting point is 84 right now.

 

 

However the altitude is HUGE in terms of how much fuel you can throw at it.  I was running a smoke free 94 starting point down here at 2000'

 

Curious part is my mpg didn't suffer between my 84 starting point and 94 starting point.

Edited September 28, 20168 yr by Me78569

Another leg done going through yellow stone 15.4 mpg.

 

Headed home today so it should be all highway, we will see if I care to do 55 or if I end up wanting to get home faster..

 

I am going to be curious how my truck does with the new tires and no camper.  

Last tank hand calced is 11.5 MPG. OBDLink is close to that number as well at the time of fill. Mostly towing the RV around on that tank.

 

243 miles / 21.119 gallons = 11.50 MPG.

@AH64ID

 

Or anyone else.  

 

Do we know how cummins calculates engine load?  

 

2 hours ago, Me78569 said:

@AH64ID

 

Or anyone else.  

 

Do we know how cummins calculates engine load?  

 

Good question.... what are you wanting to do with load or parameters? 

trying to understand if we can even use load as a tuning variable or not.  

 

Does Cummins calc load based upon what is possible via canbus ( 235 + 65 hp) or will it take into account wiretap fuel.  

 

Edited October 1, 20168 yr by Me78569

7 minutes ago, Me78569 said:

trying to understand if we can even use load as a tuning variable or not.  

 

Does Cummins calc load based upon what is possible via canbus ( 235 + 65 hp) or will it take into account wiretap fuel.  

 

Way I see it there's no way for it to take wiretap fueling into the load calc directly. It's just holding a solenoid open. It may inadvertently do it through boost and other things though.

 

I do think it is a viable tuning variable though, especially since what we are trying to improve most is the spool and cruising timing. 

Well the Quad doesn't calc load in the same manner as the ecm.

 

idle load on the quad = %9 idle load from ECM = %1 according to obdlink program. That doesn't actually mean the obdlink program knows how to decode a load value from the ecm, but something is up. 

 

Way I see it we are going to struggle to tune using the quad right now as it doesn't match the ecm.  That is why the map is using boost since there is a full range.  

 

I might be able to find what the PID is for load via canbus.....maybe.... I wish I had some documents for the protocol.

6 minutes ago, Me78569 said:

Well the Quad doesn't calc load in the same manner as the ecm.

 

idle load on the quad = %9 idle load from ECM = %1 according to obdlink program. That doesn't actually mean the obdlink program knows how to decode a load value from the ecm, but something is up. 

 

Way I see it we are going to struggle to tune using the quad right now as it doesn't match the ecm.  That is why the map is using boost since there is a full range.  

 

I might be able to find what the PID is for load via canbus.....maybe.... I wish I had some documents for the protocol.

Might have to throw out the ECM's timing all together and use the quad alone with the data it has to build a map. 

 

Is that possible? I know you guys say it has a "good" map already, but in reality it does not for every setup. 

Edited October 1, 20168 yr by TFaoro

I dunno map the ecm does some pretty nifty stuff.  

6 minutes ago, Me78569 said:

I dunno map the ecm does some pretty nifty stuff.  

Well.... what do you think is a good starting point? 

Edited October 1, 20168 yr by TFaoro

Starting point is always the hardest to find haha.  

 

 

 

4 hours ago, Me78569 said:

Starting point is always the hardest to find haha.  

 

 

 

 

12 valve static timing as a jump off point?

We can do that but we first need to be able to be sure how the timing message is formatted. 

 

I am Guessing at this point, but what I am seeing seems to be high.  

 

How do we figure out what the true timing is? Buy a diesel timing light would be my first though.