Love Monkey

I know there are tire/gear posts everywhere, but I have been looking and not finding the answer I want, haha!

Daily Driver, no hard core crawling cuz I'm new at all this right now, like to play in the mud and moderate trails, really can't afford to do a lot which means regearing at this time isn't an option.

I was thinking 33's to begin with, but a sweet deal has crossed my path and I would hate to pass it up if I can handle 35's without too much problem.

So can I do 35's with the 3.21 gearing or no?

-Love

tslewisz

It will suck but you can do it.

AK4Dave

You can do it, but other than great looks you probably won't be very happy with performance. Even with a Superchip flashpaq it probably won't be enough.

Love Monkey

aarrgh...that's what I was afraid of. Hmmm....more thinking to do...

nthinuf

Turn OD Off and you will be ok.

Have you found the faq's yet? In the drivetrain area is a great rpm chart. Measure the tires (don't use the misleading mfg's propaganda height), then play with the numbers. That will show you the OD On rpm's. To get OD Off, divide that number by .69


An example:

Auto, 3.21's, 31" tires (guessing on the actual height of your stock tires)
= 1681 rpm @ 70 mph

Auto, 3.21's, 34" tires (you're new 35's could be anywhere from 33.5-34.5 when mounted)
= 1533 rpm @ 70 mph
then /.69
= 2221 rpm @ 70 mph OD Off
This is a much more freeway friendly rpm.

My opinion is that JK Auto's are undergeared straight from the factory, and a mid-2k rpm range on the freeway is what you want to shoot for.

And another comparison:
Auto, 5.13's, 34" tires
= 2450 rpm @ 70 mph with OD On

So your OD Off with 3.21's and 35's won't be horrible. Not optimal, but livable.

Love Monkey

Ok, that's good to know. I might look into regearing costs this week but I know it's spendy.

So, I could either do the 35's and regear if I can afford it, or I will have to go with 33's for the time being and maybe do some smaller mods for awhile till I run the 33's down and can afford the regear.

Living in the desert...tires don't last forever like they did in the midwest for me.

nthinuf

To me, those numbers say that 35's with OD Off will perform better than your stock tires with OD On. Bigger, heavier tires, but you'll be running over 500rpm higher on the freeway. (still a few hundred rpm lower that where I like to be, but as I said, livable power)

Rexlba

I'm running 35's with a 6 sp and 4:10 gears and I've used 6th gear once in the past week. 3:21's would be worse than that. U will have 0 passing power and really nothing on the trails. I'd go 33's or re-gear

nthinuf

Her profile says she has an auto, not a manual...

Rexlba

Even more of a reason to re-gear or go smaller...