275/65R18 To New Size 305/55R20, Please Help

[sblue]

I went on php and printed out there gryphon manual/instructions.
On pg. 15 is a calculator on how to do this. So I plugged in my stock tire info and got 2483 (this is with the pho squish factor of .97) I also plugged in my new size (305/55/20) and got a reading of 2570.44

So if my 20"s give me less squish factor should I multiply by .98 instead, would that be about 7% ?
This would give me a reading of 2596.94 (2597)

So one last time to sum it up guys, I go to my 87 performance tune, hit custom options, scroll to tire size and enter either 2570 or 2597 (depending on which is more accurate for squish) hit enter then scroll to gear ration and ensure it says 3:73 and then I'm done?

I realize this isn't done with a gps, but this will get me closer to accurate than what I have now right?

[sblue]

Just to make things easier i think I'm going to to with the value I calculated on the gryphon instructions of 2570

I believe that's with a 5% squish factor

I'm not sure how to use a 7% squish factor with my 20"s? Would 2596 be more accurate?

[sblue]

Great! So I went to make the adjustment and I got an error code (f1)

Vehicle calibration is not supported?

And to top it off it's stuck on this and won't return to the mani menu or even shut off?!?


Help!

[Jackpine]

Don't panic, the error code 0xF1 can sometimes appear during programming. Try this:

1. Leave the ignition key in the ON position.
2. Disconnect the Gryphon at the OBDII port.
3. Plug the Gryphon back into the OBDII port.
4. After getting to the main screen, wait 15 seconds for needed parameters to be loaded.

If you still cannot program the PCM successfully, contact PHP for assistance.

If things seem to have recovered, try reloading your custom tune and use the Custom Options menu as I described. I would use the 2596 value though. The 55-series tires do not "squish" as much as others.

One more thing. BEFORE you try programming again, make sure your battery is fully charged. With the problems you've been having, the battery could be down quite a bit. (When the Gryphon does not shut off, it pulls a rather large amount of current.)

- Jack

[sblue]

Ok I was able to get into programming and insert my new value. I followed the instructions and when it was complete I went back in to check the changes. Well it still read the original value which is 2356.

It went through all the reloading procedures so why is my new value not in there?

Help! Lol

[Longshot270]

It will not save the value. Every time you load a tune you have to change to the value that works best.

[Jackpine]

Please read: http://forum.gopowerhungry.com/faqs-...ions-menu.html

The 2356 is a "placeholder" value.

- Jack