I decided to start this thread on the discussion of the electronic ESP system and Differentials. I know there are others around, but I wanted to focus on these two subjects in a review fashion. I'll let the powers at be pick me apart to tiny peices then run me over with their rigs.
Tonight I got to do some real wheelin at work. We have a pile of old concrete blocks (without any metal) and a huge mud hole thanks to the flash flood. What I knew about ESP was it was a traction control system. What I didnt know was it was accually a whole network of systems.
To start, I did some research and found that in 2006, they dropped the rear trac lock in favour of the ESP system. The ESP system, uses the ABS speed sensors and activates the brakes in an LSD fashion. Sorta like the parking brake trick. The wheel that slips gets the brake to make the wheel that grips get traction.
During a rock crawling excersize, the ESP was somewhat handy in getting some traction to the wheel trying to get traction to climb. It hums and makes its ABS sound (those that have it know it). With the ESP in partial off mode, you can't turn it off remember, it works almost as well. ESP takes over if wheel speeds get excessive.
During a steep decent awhile back, I was at an akward angle and could almost feel the Jeep rolling. The ESP did its thing, even in partial off mode. The result was the ABS releasing the brakes and adjusting the other wheel brakes so that (I assume) in the event of a slam on brakes, it wouldn't cause momentum to push it over. This is good because it helps you not roll. This is bad because I had to stop NOW and when your foots planted and your watching your front drivers wheel roll still, it gets you exicted in a hurry.
Now we get to the potentially fun part, the MUD. In partial off mode, the mud is just like any other 4x4, or so I thought. After getting into some fairly deicent crap, I did what I was told to do. Fling the mud out of the treads. After applying deicent pressure on the gas, the flinging ensued. Being an Automatic, it automatically picks up more speed, upshifting. As I start to move after a very short time, the ESP comes on and slows down the wheels. The ESP senses the tires moving X speed and the G sensors for the Roll Migration and Stabaility control sense Y speed. Now, since this is not tarmac, the wheels stop almost dead. So you feel movement begin, then come to an aburpt end. Perhaps my wheels were turning too fast? Yes, that was the case. After putting the transmission in 1, and gradually applying gas, I began to move again. As RPM increase, no sign of ESP. I try 2nd, nope. By 2nd gear, I was moving at a quite sufficent rate to clear any mud obsticles. With ESP on, forget it. Your going nowhere. Your tires dont even really turn at all. It just goes hum hum hum, RPM's stay restricted and you stay parked.
The other thing I wanted to point out was sideways movement. With ESP on, your going straight where your wheels are pointed. Not even a fish-tail, or burnout. With it off, this is where it gets strange. In one run in the mud, I was able to execute a fabulous low speed power slide/Drift. Trying the same manouvere again at the same speed, the ESP took over and deny'd me. A few more trys yeilded similar results. 2 Successful runs here, 1 or 2 bad ones there. That shows to me that the system is not as accurate as once thought. Perhaps it is the amount of throttle applied? 4-HI or 2-HI? Only further investigation will tell.
Now we move on to Differentials. Specifically the Back. Since the introduction of ESP in 2006, Jeep dropped the LSD rear end. Is the ESP that good that it doesnt require an LSD? This driver doesnt think so. Does the ESP replace the duties of an LSD? Maybe if you were driving on street made of piles of small rocks.
Or perhaps the LSD is not capatable with the ESP system. I cannot say because I am, at the mercy of Jeep, open Diff'd. What about the new Jeep Wranglers? They have full lockers! Further research found the ESP system can be completely turned off, instead of in a partial mode. That sucks for me(us).
I'd like to end this on a quesiton note.
Is there a way to fully dis-engage the ESP system?
And
In the wisdom of Jeep, will LSD and locker differentials interfere with the ESP partial system, or full on system in a damaging way?
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I hope you enjoyed. Its 2 in the morning here and Im about to hit the sack. I hope my vision was good enough to catch spelling, and my brain good enough to catch all my ideas in a literate way. Thank you all.
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