Thread: How do i fine tune the speed on my Gryphon?
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Old Tue, December 2nd, 2008, 05:41 PM
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Jackpine Jackpine is offline
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Originally Posted by 06KingRanch View Post
Thanks....that answers my question.....i had added to my tire size to see if the Gryphon's speed would go up , but didn't add enough to make a noticeable difference.

I had expected the trucks speedo to read high compared to the actaul gps speed.....but it appears to be dead on.

I wanted the gryphon to read correct so it's mileage calcs would be correct....or does it figure it off the trucks odometer?

If I raise the tire size so the Gryphons speedo is correct, will it effect any of the other Gryphon's outputs??

Many thanks.....i love the Gryphon....made a great deal of difference to my truck.....I'll give you a call when i get home in January to go over what mods make a difference, and order some custom tunes.

Scott
Glad you like the Gryphon as much as the rest of us.

You DO want the Gryphon's speed reading to be exact - it gets all its input from the PCM, and nowhere else when it's working in the "monitor" mode. With the Gryphon showing speed correctly, the truck's odometer will also be correct (even though the truck's speedo will be about 2mph high). Remember, adjusting your tire size and gear information in the Gryphon reprograms the PCM so that it interprets tire revolutions for distance and speed correctly. As a side effect, having correct values programmed into the PCM makes the truck shift at the correct speed/throttle pressure points.

The gas mpg calculations will not be TOO accurate unfortunately. I suspect the PCM is not seeing an exact value for fuel flow into the engine. The average MPG might be within +/- 1 mpg though when you do a "hand" calculation dividing miles driven by gallons added to the tank at fillup. And, the instantaneous MPG will certainly tell you when you're "guzzling" gas or just "sipping" it.

- Jack