Quadzilla fuel trip and instant mpg

[Me78569]

Well i have been doing some beta testing on an instant mpg meter and a gallon used trip.  Today was the first day i could calibrate my pumped gallons used vs the calculated gallons used.  

 

Happen to report my guess what only .5 gallon off. After calibration it us dead on.  I need to run a few more tanks, but we should have these working based on injector size and the fueling command.  Really cool stuff.

[kzimmer]

Sounds awesome, I look forward to trying it out.

Edited September 23, 2017 by kzimmer

[Mopar1973Man]

@Me78569 Hey... I would see if you could get the fuel level display as a gauge too. Being you can see the speed from the ABS I'm pretty sure you could see fuel level from the PCM as well.

[Me78569]

Nope, speed is a pin input on the ecm harness.  It is not read over ccd

[Mopar1973Man]

Dang... 

[Me78569]

Gallona used could be used to ahow how many gallons left.

[Me78569]

so I started off at %130 to get that .5 gallon difference of the quad saying I used less fuel than I actually did, I went ahead and adjusted to %135 and found that I had not swung hte otherway and had a 1 gallon offset saying I used a gallon more than I actually did.   so I went back and did %131 and we will see how close we are. 

Edited September 24, 2017 by Me78569

[trreed]

My first run at 145% was about 4 gallons over.  So now i'm trying 140% but I bet that's gonna be over too

[Me78569]

I am at 132 and pretty close.  

 

I would guess 135-138 would be good for your injectors....  Random guess

[trreed]

We will see...  Without my weekly trips to Sterling, fuel seems to stay in the tank longer, so this may take a bit longer to get zeroed in

Edited September 28, 2017 by trreed

[Me78569]

agree'd

 

I just finished up the addition of an approx wiretap fuel useage that adds to the trip as well.  I will pm you the flash

[trreed]

Neat! So before, it only took into account canbus fueling? 

[Me78569]

Yes.   Wiretap is still a "guess of %25 of possible fuel"  So if you have stretch at 1800 it would be %25 of your corrected mpg offset divided by the possible 2200 of wiretap possible.

[trreed]

Cool, I'll get that flashed in.  The gallons used always seemed to go up faster whenever I was using wiretap with the current flash.. Or canbus must've been higher as well.

[Quadzilla Power]

I have actually been trying to find out a good number for the duration of time for a 4095 CAN bus message fueling stroke on the VP44. The results are not encouraging. It seems that the pumps are electronically tuned based off their actual output. Stronger pumps will actually decrease the time of the stroke to match the mm3 number printed on the pump where weaker pumps will increase the time to match the mm3 printed on the labels.

This means that when we stretch that signal you will actually get a lot more fuel on a stronger pump than on a weaker pump. There is no real correlation between fuel delivered and time that is consistent across pumps. Its going to make estimated fuel usage when stretching really hard to figure out. 

To be honest, I don't even know what the average stroke duration is to be able to get a best estimate. If anybody out there knows this I would love to have that information. 

 

[Me78569]

I could believe that.    
 

this should still work within the design of the mpg offset tool.   At this point the rough draft is %25 of mm3 is max wiretap.  That should get "close"

 

I know know that anyone that does actually know would share.  

[Mopar1973Man]

This is one thing I hated about OBDLink setting are the same problem you left to guess or figuring out some math to get close. Now that I've switched over to Dash command is based on fuel consumed vs gallons pumped so now when you adjust the offset to match gallons the percentage offset is automagically mathed out. No guessing. This is the same setup as ScanGauge II as well it displayed what it though it burned for fuel then you matched it and again automagically maths out the offset percentage.