Trying to reset my 12. I am running 315.75.16 MTR's. I measured them at 34.25 in height from the ground and on the jeep with full weight. Gave it a go to see my rpm's at 70 and came in at almost 2700 rpm. Jeep is an automatic on 4.10s.

2700 rpm seems high to me and the 12 conversion chart shows I should be running around 2200 to 2300. Whats everyone else seeing after ProCal with this set up?

Thanks.

 

Do you have a hand held gps
You can verify speed with



Sent from my iPhone

 

Subscribed. You may want to hit up JPOP he has a lot of experience with this.

 

2700 is what mine was before 35" tires
Sounds like it needs re calibrated
Again


Sent from my iPhone

 

I've got a 12, auto, with 4:10's. My tires measure at 34 in. At 70 I'm running at about 2600 0r 2700 rpms after the Procal

 

It says to measure from the ground fully weighted.

 

I had 315/75/16 MTRs on my '07 and they measured 34.25 on the ground, so you're ok there. I've got trail grapplers on my '12 measuring 33.75 on the ground. I've also got 4.10 and with stock tires, I ran about 3,000 rpm at 70 mph. With the trail grapplers, I'm around 2,500 rpm at 70 mph.

 

My 2012 (4.10 gears, BFG 35" tires that measure 34" mounted, and ProCal) is running about 2350 rpm at 70 mph. I don't understand the wide rpm ranges getting posted with similar diameter tires and gearing unless the ProCal programming didn't work.

 

Subscribed.

 

I have a Manual 2012 so I didn't have an rpm issue but I did have a speedometer/odometer issue. I found on here somewhere that you're supposed to only measure to the top of the shoulder from the ground. Not all the way to the top of the tread, this gave me around a 1/2 inch difference in where mine was set and how it is set now. This change has seemed to fix my problem. Let me know if this helps.