05+ Mustang Speedometer Calibration

[moochman4life]

One of the coolest turn-ons for me when I decided to get the Trinity was Diablosport advertising that I could re-calibrate my speedometer to reflect changes in tire sizes. I installed the 93 tune and went to modify it (following the instructions in the manual) and the tire size cal was not listed. My Trinity is 6JSEJBB-1 running v.1r06. Is this not an option for 05+ Stangs? Mine is an 06 GT.

[mikel]

It should be there, maybe under axle ratio?

[moochman4life]

Mike, thanks for the reply. Under Axle Ratio there are two options:

1. Axle Ratio - Here you can choose multiple gear ratios (3.55's, 4.10's etc.).

2. Tire Revs per Mile - here you can choose the tire spins per mile.

If it's two, I'm totally confused. It's asking for anywhere between 500 and 2000. If this is how I modify my speedo cal how do I find out how many spins per mile my 275/35ZR18's kick out? I inspected my tire for any numbers that look like they're anything close to the "default" Trinity setting of 771...nothing. I saw a "max load" of "469", but I was just looking for any numbers at that point.

Please advise.

[moochman4life]

Mike, you know what? I just got educated:

http://www.snipertuningforums.com/viewt ... =10&t=1295

I ran a search for that "discount tire" site:

http://www.discounttire.com/dtcs/infoTireMath.dos

Pretty cool.

However, is this what is going to re-calibrate my speedometer for sure?

[mikel]

Yes, enter the tire revs per mile and it will calibrate the speedo for you when you install the tune.