Question on Johnson Rods, Gap IID, and how the suspension "thinks"
#1
Question on Johnson Rods, Gap IID, and how the suspension "thinks"
I'm picking a rig that's already got 2" Johnson Rods installed. I will also have a GAP IID tool.
So does the Johnson Rod make the sensor think it's at sitting measurably at "0" or does it make the car think it's at "homebase height" but recognizes it's 2 inches taller from ground height?
Practical example why I want to understand how it thinks: If I want to drive in normal ride height on the highway for a long road trip, well with the rods in the car will be 2 inches taller. So what happens if I used the Gap tool to set the suspension to access height? Would that effectively put me into "normal" drive height to counteract the sensors being tricked by the rods, or would doing that set the vehicle to a height that is a standard objective height from the ground?
I'm assuming it's the former and not the latter, Sorta just want to understand the relationship between any potential Gap height adjustments and the Johnson Rods on there now.
So does the Johnson Rod make the sensor think it's at sitting measurably at "0" or does it make the car think it's at "homebase height" but recognizes it's 2 inches taller from ground height?
Practical example why I want to understand how it thinks: If I want to drive in normal ride height on the highway for a long road trip, well with the rods in the car will be 2 inches taller. So what happens if I used the Gap tool to set the suspension to access height? Would that effectively put me into "normal" drive height to counteract the sensors being tricked by the rods, or would doing that set the vehicle to a height that is a standard objective height from the ground?
I'm assuming it's the former and not the latter, Sorta just want to understand the relationship between any potential Gap height adjustments and the Johnson Rods on there now.
#2
It just raises what the computer thinks is 0.
Extended and Access modes will act like normal and ding at you if you hit around 30mph and adjust themselves.
With the GAP tool, you can further alter the height up to 32mm up or down. For instance, you can drop the "normal" height by 32mm (1.25") to counter some of the lift for a long drive.
The GAP adjustments are a 2nd instance of changing what the computer thinks is 0. I have rods and my every day driving height is with the 1.25" drop using the GAP adjustment, so it nets to a 3/4" lift
Extended and Access modes will act like normal and ding at you if you hit around 30mph and adjust themselves.
With the GAP tool, you can further alter the height up to 32mm up or down. For instance, you can drop the "normal" height by 32mm (1.25") to counter some of the lift for a long drive.
The GAP adjustments are a 2nd instance of changing what the computer thinks is 0. I have rods and my every day driving height is with the 1.25" drop using the GAP adjustment, so it nets to a 3/4" lift
#3
It just raises what the computer thinks is 0.
Extended and Access modes will act like normal and ding at you if you hit around 30mph and adjust themselves.
With the GAP tool, you can further alter the height up to 32mm up or down. For instance, you can drop the "normal" height by 32mm (1.25") to counter some of the lift for a long drive.
The GAP adjustments are a 2nd instance of changing what the computer thinks is 0. I have rods and my every day driving height is with the 1.25" drop using the GAP adjustment, so it nets to a 3/4" lift
Extended and Access modes will act like normal and ding at you if you hit around 30mph and adjust themselves.
With the GAP tool, you can further alter the height up to 32mm up or down. For instance, you can drop the "normal" height by 32mm (1.25") to counter some of the lift for a long drive.
The GAP adjustments are a 2nd instance of changing what the computer thinks is 0. I have rods and my every day driving height is with the 1.25" drop using the GAP adjustment, so it nets to a 3/4" lift
Current tires are regular 18" road tires because I asked the seller hold off on adding A/Ts for now since it essentially would've just been added their cost to the list price, so I can make the very long drive on those tires - although I do plan to get something a bit beefier once I get home. Nothing too crazy because it's more for adventure fire road mini-overland journeys in the mountain than for rock crawling, but will also get winter tires since I live in the mountains PLUS a benefit of two sets of tires is half the wear on each in a calendar year - although I hate the cost of two new sets.
#4
copy that, thank you - so I could use GAP IID to set it to -32mm and then be at a better highway height, which would basically equate to a .75 inch lift from standard, and then at any height, including the 30+mph "lower" height I'd still maintain that .75 inch extra? In other words: Just wanted to confirm that if I lower the standard height using the Gap Tool to help for the drive, I'm not going to be hitting an on ramp and at 32mph an hear the car lower itself onto the tire because it's compensating for the rods lol.
Current tires are regular 18" road tires because I asked the seller hold off on adding A/Ts for now since it essentially would've just been added their cost to the list price, so I can make the very long drive on those tires - although I do plan to get something a bit beefier once I get home. Nothing too crazy because it's more for adventure fire road mini-overland journeys in the mountain than for rock crawling, but will also get winter tires since I live in the mountains PLUS a benefit of two sets of tires is half the wear on each in a calendar year - although I hate the cost of two new sets.
Current tires are regular 18" road tires because I asked the seller hold off on adding A/Ts for now since it essentially would've just been added their cost to the list price, so I can make the very long drive on those tires - although I do plan to get something a bit beefier once I get home. Nothing too crazy because it's more for adventure fire road mini-overland journeys in the mountain than for rock crawling, but will also get winter tires since I live in the mountains PLUS a benefit of two sets of tires is half the wear on each in a calendar year - although I hate the cost of two new sets.
If you have the bluetooth version, you can save the different height profiles you make.and choose them with 1 click
The following users liked this post:
KH406 (04-06-2023)
#5
I'm curious about driving for extended times in access height. Both the landrovers and grand Cherokee have air suspension with access heights, but both cruise above minimum height. I wonder if access induces extra strain on suspension and steering. I'd think there is a reason this isn't automatically cruise height as it should net better aero.
#6
I'm curious about driving for extended times in access height. Both the landrovers and grand Cherokee have air suspension with access heights, but both cruise above minimum height. I wonder if access induces extra strain on suspension and steering. I'd think there is a reason this isn't automatically cruise height as it should net better aero.
In my case I was sort of wondering if the Johnson Rods were tricking the suspension to lift the rig, but then the gap tool was manually overriding that to lower it, would putting any unnecessary strain from "competing forces" on the suspension but, it sounds that's not what's happening down there, and that the suspension just "relaxes" at a different height without fighting itself between the rods and the gap settings.
#7
#8
From what I can tell, the suspension hits it's physical maximum height in the "super extended mode" regardless of whether you have the johnson rods or not, the only difference is that the system might not "think" it's in super extended mode, despite that it can't physically go any higher. I think. If I'm following it all correctly lol.
#9
If the values for the standard height are set too high (and/or Off-Road height on a L322-02) the
suspension can reach a fully extended condition in off-road mode. In this condition, there is no
upward suspension travel. There is a severe risk of damaging components and the vehicle
can become uncontrollable in this state! GAP Diagnostics assumes no liability for damages
or injuries incurred during use or resulting from the use of the IIDTool.
suspension can reach a fully extended condition in off-road mode. In this condition, there is no
upward suspension travel. There is a severe risk of damaging components and the vehicle
can become uncontrollable in this state! GAP Diagnostics assumes no liability for damages
or injuries incurred during use or resulting from the use of the IIDTool.
#10
Don't they mean "downward" travel though? Regardless, if you roll around like that you are going to get a suspension fault for being "out of range" and get dropped to normal height. One should take great care to set their modified suspension calibration such that there is enough capacity for the EAS to go into Extended Height when high-centered (and don't try super-extended because that effectively IS super-extended).