ok i ordered a gryphon today and bill is going to put a 87 perf tune on it. i forgot to ask if i will be getting that tune when i get my programmer or if it will be emailed to me later. do you know how this works ?

 

im pre sure u will recieve your gryphon without the custom tune and he will email it to you later....thats how mine worked...i've been running canned tunes for almost a month now and like them alot...i was alot more excited until i found out my gryphons not very accurate on the mileage but its all good

 

The mpg readouts seem to be off in my Gryphon too, as well as in the info panel in my dash. The dash average mpg seems to use a longer interval than the Gryphon and it tends to be closer to the actual average for a tankfull of gas. I think the problem is in the length of the "history" in the programmer.

But, since getting my custom tune, my actual gas mileage is now about 0.3-0.5 mpg better than the figure shown in the dash readout, which used to be VERY close to my actual mileage. In case anyone's wondering, my odometer is within 0.1 miles for 100 actual miles driven, so I'm confident my miles divided by gallons is correct.

- Jack

 

im not fortunate enought to have a dash panel in my ole truck lol...so how does the gryphon (or dash for that matter) calculate the mileage?? this is more a just out of curiousity question...does it simply take the amount of fuel being dumped into the truck and compare it to the speed of the truck, then do the calculations and read it out?? im sure theres a flaw in my thinkin as that sounds way to simple

 

No, I think you're probably close to the way it's done. If I were programming the thing (since I used to teach this stuff), I'd use the miles per hour input to the PCM and divide that by the gallons per hour that is being controlled by the PCM. When you divide, the "hours" cancel and you're left with instantaneous MPH. Easy, grade school math and simple to program. The units of measurement may be different, possibly meters per second and cc's per second, but the principle is the same.

The "average" MPG is a bit harder to nail down, and I suspect the message center microprocessor on my dash does it a bit differently than the Gryphon, because the Gryphon's figures change more often than the ones in the dash (if I monitor both). One approach could use a miles driven figure, say 100 miles (which the PCM knows) and divide that by the fuel fed to the engine during those 100 miles (and the PCM either has or can infer that number too). You could update this result every 10 seconds or so. If you haven't driven 100 miles since the last "reset", you can just divide the current distance by the current fuel used.

The Gryphon may have to use a shorter distance for its calculations due to the "word" size in it's microprocessor.

And, weshova, good programming is always simple, because digital logic is simple. If a program starts getting complicated and hard to understand, it's a sure sign you're looking at the problem in the wrong way.

- Jack

 

When I first got my Edge about 2 years ago, I compared it's calculation to my actual mileage figured by miles driven and gallons used. It was off by almost 2 mpg. Plus, just watching the thing gave me indigestion and anxiety! So, I removed it from the screen and have not looked at it since.

I have kept a spreadsheet for mileage for 70,000 miles. That is the one that counts and for a "big ole truck", she does not do badly.

 

Hey Josh,

Your Gryphon will be shipped on Monday with 3 stock tunes: a tranny only, an 87 tow, and a 93 performance. Custom calibrations are mailed to you later. If you have a second, check out our website; I put a note on there this evening about custom tunes.

 

Is it digital logic the type of programming you used to teach?? I use to want to be a computer programmer but that changed shortly after I started C++ lol....for the average i figured it just totaled up the instantaneous figures and divided it by the number of inputs, but ur logic sounds more correct as it is a whole separate system and independent of the instantaneous mpg

 

hey i had just emailed u but u pretty much answered my question. so the order went through and everything? i remembered yesterday that i had a limit on it so i called my bank and uped it, i guess i did it in time. but i still dont see the order on my bank statement.

 

Yes again, to the digital logic question, but C++ is just a "language" that is used to communicate a "script" of actions that we want the digital microprocessor to carry out. It's something like writing a script for an actor in a play, except your actor is the microprocessor. You simply have to tell him what to do, when, and maybe how. C++ is one of the languages you can communicate in, Basic and Java are others. (There are many, many more). The term "digital logic" is usually used to describe hardware design - using electronic devices to build a microprocessor - something I also taught.

Your approach could work also, weshova. In fact, it might even be how it's done. I think my approach is more direct and simple, therefore less prone to calculation error. But, I did not write the code, and my approach may not be the one that was used. (However, as the number of inputs increase, both methods should tend to give similar results.)

One of the interesting things about computer programming, is, "There are NO best approaches". There are, however, "better" approaches. But we can never say we have the "best" one!

- Jack

 

thanx for the response jack...im trying to learn about these trucks in the short time I have/will own them lol