MPGuino settings for 49 state Honda Civic VX.

[stewie]

WD40 ...thank you. I bow to you now! Andrzej thank you very much first and foremost. I knew wiki numbers were not accurate. I know this car but i don't know mpguino so numbers were off. BTW does tire size matter. I have 175 instead of 165? Are the mpgs you getting off to the upside or downside?

one setting is missing.......this one? what you got for this one?

Pulses/2 revs = ????

[WD40]

stewie: I have 175 tires as well.
Pulses/2 revs = 0 on mine.
The mpg on the mpguino were to high by 1.14 mpg on a 426 mile tank so the new # I'm testing for Microsec/Gallon = 0257072561 instead of 0257763367

[stewie]

Cool cool many thanks!!! This is exactly what i need. Just curious you have 12 or 10 gal tank. Mine is 10 gal yet most ppl have 12 gal tank. Also are you calculating bigger size tire when calculating final mileage? This is important if you tweaking guino. How are you changing calculations on Microsec/Gallon when you change those values?

Tire size calculator

stock size 165/70/13
+1 size 175/70/13 so

if you odo reads 426 miles one needs to multiply x2.5% = 426x2.5%= 426+10.65= 436.65 odo final miles divided by total gals.
With bigger wheels tires roll too slow as tire is bigger therefore lower milage and 2.5% corrections needs to be applied. You probably know that.

[WD40]

stewie:
my calculations are hit an miss by trial and error over the years, i have adjusted many times in the beginning and just today I redid it again based on Andrzej methods of calculating, however i tried his method and it increased the error so I reversed his calculations and its going the correct direction now however still way to much of a correction so I went again with my hit and miss method which seems closer.

[stewie]

Cool but what i mean is that your ODO with 175 tires is inaccurate in first place as yours and mine for that matter bigger 175 tires roll slower then 165 tires as they roll faster. What that does is on 175 your ODO is short by x2.5% of total mileage on miles. So if your ODO shows 426 miles it's NOT 426 but really 436.65 so then you divide by total gallons burned. If not adjusted/accounted your manual calculation will be off. So i guess what i'm trying to say that your figure might be correct if you are NOT adjusting manual mileage to tweak guino. If you had stock tires you would not need to do this. Hope we can collectively figure this out here ))) You're getting pretty good MPGs bro. What psi on tires you running. Andrzej if you can help us figure this out it would be great. I just started this so right now your calculations are overwhelming me a bit. Maybe in time i will re-read and reapply. I'm hoping we can get correct settings for the this device.

[WD40]

stewie:
gotcha .. never worried about the tire size % difference before, but taking that into account the mpguino was only off by 0.31 mpg this time by to little at the 0257763367, so I need to readjust it in the opposite direction then .. I will recalclate this and get back to you, thanks for your persistence.

[stewie]

lol...sorry bro that i'm being too persistent. I'm guess i'm anxious to get this right.
Yes please let me know when you get more info. I will be testing both of your figures. I did little test run on the way back from gym and nubmers displayed look damn accurate to me. I'm happy to be in the ball park so i think you again. I knew that wiki posted numbers are way off.

[AndrzejM]

Originally Posted by stewie

That's great explanation. Thank you. Sorry for so many questions but i'm trying to understand this device better and without set values i just don't know. My tank is just running out now, another day or two so i would like to get settings correct so i can test with full tank. It takes 2 weeks to empty my tank so if i won't get it right it will probably take few tires so few months.

I did GPS speed test today and MPGuino showed slightly slower speed then GPS app on my phone. I believe GPS on my phone showed same speed as speedometer in car HOWEVER my speedometer in car is incorrectly slightly as my tires are one size bigger 175 instead of 165 as you that's how i bought the car. So if i understand you correctly my vss/m and MicroSec/Gallon will be different then default of (vss/m = 8208 MicroSec/Gallon = 0279235000) due to slightly bigger tire size?

Should i adjust VSS delay to get speed right or VSS value? Also mpguino does not have rpm guage. I do notice instant mpg changes as soon as i change any values including REVS and Delays.

Pity v0.86 doesn't have rpm gauge. My "canadian" metric version has it and it's great for diagnostics. But if you mounted MPGuino on your own you can change the code and set up rpm gauge. I can look into the code and provide you all the changes that you need to do that.

Anyway - you've mentioned that your speedometer can be off due to different than oem tire size. Speedos are off very often by 5 to 10% so don't worry about that. You may calibrate it (mentally) with GPS and that will give you how big is the difference.
But if speedo is off then probably your odo is off too. You should check the difference with GPS or mile markers (10 miles or more), to be sure what exact distance you're doing on the tank. Then you can calibrate MPGuino for the exact value and relay on that to get your FE numbers.

[AndrzejM]

Code changes for v0.86 to have Big RPM gauge

Just find the code and add the code marked in red

Define display func:

pFunc displayFuncs[] = { doDisplayCustom, doDisplayInstantCurrent,
doDisplayInstantTank, doDisplayBigInstant, doDisplayBigCurrent,
doDisplayBigTank, doDisplayBigRPM, doDisplayCurrentTripData, doDisplayTankTripData,
doDisplayEOCIdleData, doDisplaySystemInfo, };

Define display func name:

displayFuncNames[x++] = PSTR("Custom ");
displayFuncNames[x++] = PSTR("Instant/Current ");
displayFuncNames[x++] = PSTR("Instant/Tank ");
displayFuncNames[x++] = PSTR("BIG Instant ");
displayFuncNames[x++] = PSTR("BIG Current ");
displayFuncNames[x++] = PSTR("BIG Tank ");
displayFuncNames[x++] = PSTR("BIG RPM ");
displayFuncNames[x++] = PSTR("Current ");
displayFuncNames[x++] = PSTR("Tank ");
displayFuncNames[x++] = PSTR("EOC/Idle ");
displayFuncNames[x++] = PSTR("CPU Monitor ");

Display func body:

void doDisplayBigTank() {
bigNum(tank.mpg(), "TANK", parms[metricIdx]==1?"L/K ":"MPG ");
}

void doDisplayBigRPM() {
bigNum(instantrpm(), "RPM", parms[metricIdx]==1?"rpm ":"rpm ");
}

void doDisplayCurrentTripData(void) {
tDisplay(&current);
} //display current trip formatted data.

[stewie]

Andrzej you're the man! Thank you. I found ISP port on the board. Is that the serial port in need to use to get into chip? How do i do that? Is there a guide for doing this? Are there any other functions that can be added to 0.86 guino as well. What would i use RPS for in terms of calibration?

Ok so i tested speed with GPS and here is what i found. I think, i'm not sure but i think speed on guino is accurate. I did find GPS to change the speed little quicker .30mph then guino however isn't GPS delayed as its got all the way to satellite and back. Wouldn't latency of GPS cause inaccuracy in speed reading on GPS? The numbers i'm getting now are more believable then wiki. On weekend i will have to rewire guino as its only connected to key on power so resets all settings when key off. Need to find constant +12V. Thinking i will run it off car stereo. The clock which is missing btw is too hard to get to. Also there is option of tapping wires close to fuse box as well.

I found little info on calibration. Will try that when i get my constant +12v fixed

"cmags, re: calibration:
After the initial guess, the version we have here will benefit from a "true up" when you refill your car. Basically you
1. top off the tank
2. note your milage on the odo
3. reset the guino
4. drive for hundreds of miles
5. go to the same pump at the same station pointing in the same direction (same time of day/temperature would be nice)
6. fill up the tank to the same spot/number of clicks
7. note the change in mileage on the odo, see if it matches the miles on the guino
8. note the gallons it took to fillup the car, see if it matches the gallons on the guino

If 7 or 8 aren't reasonably close, then note the percentage that the reading is off and adjust the vssPulsesPerMile (for 7) or injectorGPH (for 8) at the top of the source code (at the top of this thread) by that percentage and reload it onto the guino."

What i'm interested in is whether 2.5% tire adjustment Tire size calculator will have to be added taken into account in #7 on odo. It is plausible that manual calculation are in fact in synch with mpguino when taking into account 2.5% adjustment.