Upgrading to 37's

Heavyfoot · Jan 18, 2017

So I was running 35's with *** ****** running GH tunes from no limit and after I swapped out my worn out 35's to 37's my truck tends to hold on to the gear longer and have it's shift points off. I looked in my sct tuner and it doesn't have the option for 37" tires.
So my question is...what are u guys doing who swapped to 37" tires? Are you getting some sort of trans tune or are u getting a new tune all together? Or is this something I just have to deal with as the consequence for going with such a large tire and not regearing the truck?
I know a lot of you guys are running this size tire or bigger so hopefully y'all can help me out.

Thanks

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Laynrocker84 · Jan 19, 2017

When I ordered my gh tunes, I told them I was running 37's. They loaded my x4 with a tune for 37" tires. I'd give them a call

TLyons90 · Jan 19, 2017

Agree that you need to get with whoever got you the GH tunes and get them to update them for 37s. Going from 35s to 37s your gear ratio is now off and probably causing that issue.

sootie · Jan 19, 2017

I'm not aware that 6.7s can compensate for that large of a tire size. but ya, your shifting will be off because of the tire swap. just have your tuner raise the shift points slightly.