After changing to 3.73 Gears.

[2007VortechGT]

After chaning to 3.73 gears from 3.31, I Disabled the Use Vid. Final Drive Ratio set to 3.73, Changed my tire Rev's Per Distance 786.00, No Don't I need to rescale my shifts, If so could someone please explain on how to go about doing this, is there any other settings that need to be set. Thanks everyone. I think perhaps my shift issues at wide open throttle pertain to me never chaning the shift speeds. I've also Included my tune file. Remember this is the Base Tune file and my Diablo file is stacked ontop of this one. The Diablo programmer uses what ever tune file thats orginally in the computer and modifies only the fuel air spark so on, but leaves trans information unalterted and intact.

[lito]

If you gave the PCM the right info you don't need to play with the shift schedule.

BTW, Why don't you do a read with the predator tune installed and do a new HP tune with that info and put the diablo on the market?

[2007VortechGT]

Well see the nice guys over at DiabloSport listened to the wonderful people at vortech, that want people to use the provided tune but will not allow you to really modify the tune withen the predator programmer, and due to vortechs request made the programmer unreadable due to checksum errors when using apps like hptuners. I wish there were a such thing as a real tuner in vegas although there all jokers.

[RWTD]

As lito said, a Ford is different than a GM, in that you do NOT have to modify the shift point MPH settings. As long as you set the Axle ratio, the pcm will calculate all this on its on, based on the gearing difference. It's really rather simple on a Ford.

Now, if your WOT shift points aren't hitting on the commanded shift point RPM (due to say tire changes, loose converter, etc), then you lower/raise the shift point MPH until it is precise (just like on a GM). Also, to note, if you use the Tire Revs, the Ford pcm will not auto calculate from it, just the Axle Ratio. So say when we already have a customer's vehicle shifting dead on to the commanded, and then that said customer changes their tire size, there are some of us who program in the actual effective axle ratio, instead of using the tire revs, as everything will fall in line this way.

Also, no, DiabloSport doesn't make them "unreadable". The problem is with how HPT's backend is, and how it calculates checksums. It's a rather easy workaround, from a programming standpoint. If using SCT or DiabloSport, all the files are already there in the software. You just type in the calibration ID or the boxcode, and they pull up within the software. If they aren't, you do a backup and shoot them over to the companies, and then they add them in. HPT's licensing strategy requires that you read the file, and then modify it. If you send the file to HPT, they could add it in their database.

Regards,

James

[2007VortechGT]

I sent the diablo file over to bill and he said nothing can be done. Also I have changed the tires on the rear of the vehicle from the stock tires to Nitto NT55RS, I Measured the tire in inches from the ground to the top, and divided that by 20168 and that is the amount of tire revs I punched in 700 so my speedo is correct, but your telling me there is something else that I need to do correct my problem.