SCT revs per mile

03 tx pwr stroke · Oct 25, 2012

I'm running Matt's SRL file and I am trying to set my revs per mile. My tires are 285/75/16m or 32.8" tall. Works out to 103.04"= 1 rev. 63360 " per mile. 63360/103=615. Truck shifts hard and has what I describe as a stutter when it shifts unser hard acceleration. Any ideas? Just replaced the trans with a brand new unit from Ford less that 1k miles ago. Any ideas?

Also, someone told me that they think my revs per mile is way off. any help?

Dave · Oct 25, 2012

615 is dead on

Dave · Oct 25, 2012

http://www.gordon-glasgow.org/tirecalc.html

03 tx pwr stroke · Oct 25, 2012

Awesome. Thanks man.

HeavyAssault · Oct 28, 2012

Was the 615 based off what the tire rolled when on the truck?? I have found the manufacturer tire revs way off from my own measurements.

Mdub707 · Oct 29, 2012

Have you talked to your tuner about this? Eric always told me not to mess with any of that stuff because he set it up in the tune.

HeavyAssault · Oct 29, 2012

Mdub707 said:
Have you talked to your tuner about this? Eric always told me not to mess with any of that stuff because he set it up in the tune.

My experience has shown they will use a generic value if you don't give them the tire revs you want them to use. If the SCT allows you to apply the most accurate setting why not use it??

Zmann · Oct 29, 2012

I mess with that and all the shift stuff to fine tune my tunes

but the reason I don't have Eric's anymore is I couldn't fix the shifts
so I went to Gear heads and still fine tuned

now I just bought Wildman's and haven't had to tweak anything yet but it's still in adaptive learning

Mdub707 · Oct 30, 2012

HeavyAssault said:
My experience has shown they will use a generic value if you don't give them the tire revs you want them to use. If the SCT allows you to apply the most accurate setting why not use it??

I haven't had a single tuner yet who hasn't asked me my tire size when creating tunes for me. Eric has always asked me what tire size I'm running, and told me not to touch the rev's/mile. If you change tire sizes or something, then yes, but if the tune is already written for it you're probably just changing it unnecessarily.

Zmann said:
I mess with that and all the shift stuff to fine tune my tunes

but the reason I don't have Eric's anymore is I couldn't fix the shifts
so I went to Gear heads and still fine tuned

now I just bought Wildman's and haven't had to tweak anything yet but it's still in adaptive learning

I've always messed with shift firmness stuff, but that's it. I am of course still using an X-cal2, so it doesn't have all the neat features the X3 does. Eric's trans tuning has always been spot on for me, but I have had issues with others who are pretty popular. I haven't tried Matt though yet, and plan to do so.

HeavyAssault · Oct 30, 2012

Using a value such as 35" tires yields a wide range of tire revs. The tire manufacturer value given on their web site is based upon the wheel that they used during their measurements. We all know information shared is information gained. How you use it is up to you.