AEV Procal question
JK Jedi
Joined: Sep 2012
Posts: 4,364
Likes: 107
From: missoula,mt
I just had 35" Nitto trail grapplers installed from 33" GY MTR with Kevlars and I am still having the same issue as the 33's. I can get my speedo match my GPS no mater which way I go. I drive using my GPS for speedo. Lowered and raised the tire size a 1/4" either way and its always off. And I also use my Procal to adjust. 2011 JK Sport 6 speed manual.
JK Freak
Joined: May 2011
Posts: 673
Likes: 0
From: Houma, La
you need to move it further so try moving it 1" in either direction then adjust from there. You will get it dialed in you just need to mess around with it for a while. I think ultimately on my 285/75 ~33" I have 31 1/2" or 31.75" loaded and it is spot on both odo and speed.
JK Junkie
Joined: Feb 2013
Posts: 2,013
Likes: 0
From: West Richland Washington
I did that so many times I gave up. I had my new Nitto's installed last week while I was offshore. I had Brian at Cajun Offroad measure my tires the way they should be for the Procal update. On the way from Lafayette, La to Houma, La, I stopped 3 times adjusting 1/4" at a time and either endind up higher or lower than my GPS. I checked my GPS in my wifes Dodge Nitro and it was on the money with her speedo. I really don't know what to do with it anymore. Measurement on the Nitto's was 34.5. Put that on the Procal and it was off 2 mph higher than my GPS. Raised it to 34.75 and was 4 mph faster, lowered it to 34.25 and was 2 mph lower than my GPS......
JK Jedi
Joined: Sep 2012
Posts: 4,364
Likes: 107
From: missoula,mt
X2. I would try and reset it back to base and start over. I know that AEV says sometimes you have to set the ecm back to stock and start over. It is fast and easy to do so probably worth your time.
JK Newbie
Joined: Nov 2011
Posts: 54
Likes: 0
From: Englewood, Colorado
I had the same problem until I took the mesuerment from the center of the wheel to the ground. I got 16.5" then I X2 and came up with 33". I'm running 315/75 x 16 GY Duratracs which according to GY website should be 34.6". Now my speedo is right on with my GPS. I think it matters on how heavy your Jeep is and PSI in the tire.
JK Freak
Joined: May 2011
Posts: 673
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From: Houma, La
Thread Starter
JK Newbie
Joined: Mar 2011
Posts: 92
Likes: 0
From: Winterfell...winter is coming
Thanks guys for the replies. I have the right speed according to my GPS but when at 70 MPH my RPM's are at 3000 seems a little high. I thought the AEV Procal would change that if the Speedo was right on, which it is. If anyone is running the same tires and AEV Procal let me know what you set the Procal to. Thanks
JK Junkie
Joined: Feb 2013
Posts: 2,013
Likes: 0
From: West Richland Washington
Thanks guys for the replies. I have the right speed according to my GPS but when at 70 MPH my RPM's are at 3000 seems a little high. I thought the AEV Procal would change that if the Speedo was right on, which it is. If anyone is running the same tires and AEV Procal let me know what you set the Procal to. Thanks
JK Newbie
Joined: Feb 2013
Posts: 21
Likes: 0
From: Nj
Thanks guys for the replies. I have the right speed according to my GPS but when at 70 MPH my RPM's are at 3000 seems a little high. I thought the AEV Procal would change that if the Speedo was right on, which it is. If anyone is running the same tires and AEV Procal let me know what you set the Procal to. Thanks
JK Junkie
Joined: Feb 2013
Posts: 2,013
Likes: 0
From: West Richland Washington
i think the gps uses the same same speed input as the speedometer vs real gps speed. My speedo and gps stayed perfectly in-sync before and after re-programming, and it was obviously incorrect before re-programming. That disappointed me, i thought it would be a true gps speed.