FYI I went from 3.15 to 3.55 and I also changed tire size. I used a Ford ProCal 4 to change both the gear ratio and tire size so my speedometer and shift points (I have an automatic) are accurate.
The ProCal 4 device does work for the S650. There's a fairly extensive menu of things you can change, diagnostics, etc but I'm not aware of any actual ECU or TCU tunes that are available to use with it.
I put Ford Performance HP wheels on this summer. They're exactly the same specs as the Dark Horse non HP wheels and they were only $880 on sale. I like how the matte black finish looks.
FWIW I just had the battery replaced by the dealership in my 2024 GT. Apparently after doing some other work they got a low battery voltage message on the dash. They checked the battery and confirmed it was in fact low so they replaced it. Seems like Ford might have some battery issues with some...
My wife and I went this past June and it was a great experience. Learned a lot about the limits of the car. My wife was kinda unsure at first but at the end of the day she asked if we could come back and do the two day road course session. Well worth doing in our opinion.
I swapped my 3.15 diff for the Ford Performance 3.55 diff. It took a lot of investigating by my dealer but they eventually figured out how to recalibrate for the new gear ratio. They used a Ford Performance Procal 4 tuner. In the menu on the tuner there's a section for changing the gear ratio...
These are what I'm considering. Says they will not fit but everything I've been told is that's because the TPMS is different which I'm going to replace anyway. Offset is exactly the same as the OEM performance pack wheels but each wheel is 1/2" wider on the ones here.
Thanks much. The setup I'm looking at is 10" on the rear with 52.5mm offset and 295/35 tires so I'm thinking I'll look every bit as tucked if not even a little more.