Gear ratio change in the factory hp tune?

[saleen24]

I have a "01" Mustang GT (U7146) and was wondering if I could modify the gear ratio in the "factory HP tune"?, I never updated to the latest revision if there is one. Last time I checked i can only modify the gear ratio in the 93 octane diablo tune. I just want to be sure before I do any further modds. Thanks!

[mikel]

Yes, this will work, but you should update to the latest revision as it may not work in an older revision.

Thanks

[saleen24]

so do you mean "yes" as in gear ratio change in factory hp tune will work with the latest revision but not the old version.Also if I update to the new revision wouldnt that unable me to turn off my rear oxygen sensors?

[mikel]

OK, heres the trick.
Install the tune to your car with 7r50d with the rear o2s turned off.
Now, go in and do a read extra tune, then export the extra tune from the Pred to the PC.
Then restore your backup.
Now, update to 9r05, install the tune you exported as a custom tune, then modify that tune for the gear change, all set.

[saleen24]

Wow! Im so behind when it comes to technical stuff, I never hook-up my predator to my pc nor do i have the equipment(wires) to do so. To be honest I have a pair of MILS I still use so I don't have to go the the predator to mess with 02 sensors. Also I love the 93 diablo tune so if I get gears I'll probably stick with the 93 diablo tune anyways. One more question, if I have 373's gears and for some reason I have to go to the ford delearship for service and I reinstall my original factory tune would the only thing that would be off is my speedo? Would my car have a driviability issues(PCM woe's) with the steeper gears and original factory tune besides the speedo being off? My car is a 5-speed.Thanks, Im gonna try to become more computer savy the the predator

[mikel]

Speedo being off will be the only problem in that case, yes.

[v6procharged]

your mileage will be wrong too, if you drive it w/o putting the tune back in it.