Agile Off-road test of traction with roller test gear- no traction control???? ETA (2/22): PART 2 OFF ROAD MODE

[pmatusov]

Out of curiosity, can you have a limited slip differential AND a locker on an axle?

Plenty of examples, including LSD + locker in the center diff.

 

[INEOS OG]

View: https://youtu.be/URuanFs17oY?si=M3PGw1oe-jmdCL7g


So, when you lock everything up, it's good- but it appears that there is little to no electronic traction control. Zip. Nada.

In standard high or even in high with center lock, with a single tire on each axle spinning, it won't go.

So this means to me that at least in something like snow/ice, it isn't going to be great. Get slow, and lock things up, sure, good. But I think I'm going to leave it in the garage tomorrow for the drive up I70 to Vail, and the nod goes to the JKL.

Working as a proper 4x4 should.

 

[nuclearmonkey]

Just came back from a trip from San Diego to Copper Mountain and back, including I-70 between Vail and Denver, U.S.550 from Durango to Montrose, U.S.50 from Montrose to Buena Vista, U.S.285 from CO 470 to U.S.160, you name it.
The Grenadier never once felt loose-footed, including ice going up side roads and fresh snow on pavement.

I found it dozens of times that full-time differentiated 4WD works wonders on slippery roads. In an old Disco 1, where the front is much lighter than the rear, a center diff lock helped - no difference with the Grenadier.

Were you driving with the center did open in the grenadier, or locked?

Thanks in advance!

 

[pmatusov]

Were you driving with the center did open in the grenadier, or locked?

Thanks in advance!

Open. Never had to lock it on this trip, even when climbing snowed-in, iced-over, neighborhood streets.

 

[MileHigh]

Added this to the OP, but here it is too. I still don’t get what is going on. I’ve driven in loose gravel and now some snow and it does pretty well. Had a side slide in snow that took me by surprise, but corrected it quickly- and I think that was more an overall traction/tire thing than a 4x4 mode issue.

I personally think that in standard 4x4 everyday mode that the traction control should kick in earlier. In this new one they measure brake surface temps- and it is trying to do something, but it doesn’t seem to intervene hard enough to get the traction wheel to turn.

Not a 4x4 engineer, but it seems like a limited slip would be a non-software/brake-assist way to keep tires rolling. It isn’t like a limited slip on the rear is going to jack up the turning radius.

It would be nice if IG would release the logic/set points for at least the traction-control aspects of the system. The ESC with speeds and, turn, and yaw speed I would think is harder to explain.

I guess what I did learn is don’t muck around at less than 1500 rpm, since you will be putting heat into the brakes, but not adding any real motive force.

View: https://youtu.be/9PJ47IZ1qMc?si=XAtPAPJX9MdrqnEt

 

[C-Mack]

Interesting video but would like to see it repeated with the original stock size tires. The 3% to 4% rolling diameter difference might be enough to impact original calibration of the traction control system. Certainly willing to be wrong but it would eliminate tires sizes as a variable.

 

[MileHigh]

Interesting video but would like to see it repeated with the original stock size tires. The 3% to 4% rolling diameter difference might be enough to impact original calibration of the traction control system. Certainly willing to be wrong but it would eliminate tires sizes as a variable.

I agree, but since this is at a steady state (un-spinnng tire) I’m not sure what the difference would be? Also, if changing tires (they don’t look that different) that little bit causes the system to not be effective? That seems off. Yes, perhaps the stability control, but as long as all the tires are the same size?

 

[C-Mack]

I agree, but since this is at a steady state (un-spinnng tire) I’m not sure what the difference would be? Also, if changing tires (they don’t look that different) that little bit causes the system to not be effective? That seems off. Yes, perhaps the stability control, but as long as all the tires are the same size?

Don’t disagree, in principle the vehicle shouldn’t know any different about what size tires are being used but for a little added scientific rigor establish a baseline or control (stock vehicle) then introduce variables one at a time and see how the results change. Perhaps increased tire diameter has an impact on the amount of engine torque the traction control software senses through the drivetrain for a given engine rpm? Perhaps this would take the system out of its normal operating regime and may explain the low amount/force of differential braking torque demonstrated in the video? If nothing else, it’s just being thorough as possible during an experiment or testing.