Before I purchase a credit and find it's useless does anybody know if there is a way to change the gear ratio in a JTEC+ tune? I can't see a way but I've attached the tune if anybody is interested in looking .
As far as I know, it cannot be done. The Pinion Factor would be the way to do it, but HPtuners does not allow that to be changed for some reason. Hopefully there are still more features to come.
There are Final Drive Factor Max and Min, but they do not seem to be helpful for speedometer correction.
As far as the WJ's (99-04 Grand Cherokee), Ive seen superchips allow tire size adjustment on 02-04 4.7 V8's, not sure the process they use, but I used the F5 flashpac on my 04 back 2014 ish for my 37's. Ive since went back to factory tune (un-married the F5) and sold it a few years ago. I wasnt smart enough to copy the F5 91 octane tune on a separate file before un-marrying it, so I could see what it all changed. Ive never tried on HpT because my jeep never sees pavement anymore and it also has 4.56 gears to help compensate for the 37s, keeping the mph vs rpm near what factory was.