100 in the sand dunes... problems! (80 comparison)

[e9999]

well, had both the 100 and the 80 at SnT so I did some tests (of sorts) to compare their ability.

Short story: not a perfect comparison so a bit of uncertainty, but the general impression is that the 100 did OK but nothing like the 80.


I had the 100 out with tires down to 20 psi. Not very low admittedly. But I had the 80 at 20 psi first too and there was no trouble, it went just about everywhere. Not so with the 100. It was bogging down every so often, even on some mild slopes that were giving no trouble to the 80 at all.


I did one final test where I had the 100 (with 20 psi) try and go up a slope, about 30 or 40 deg, about 30 ft high. Even with backing up and speeding towards the slope, it could not clear it, was bogging down at the top each time. This was with the CDL on, in Low.

Then I took the 80 (with 12 psi) and I decided to do a test where I would start fully unlocked, see how high it would go, add one locker at a time, and see when I would finally clear up the dune. Started out fully unlocked, and it went right over it, no problem. Dang...

Is this last comparison fully valid? No, cuz of the tire pressure difference (I didn't want to bother with lowering the 100 all the way down to 12) and that matters a lot in sand. But I had the CDL on with the 100 and not with the 80. Plus I was going faster with the 100 I think. All in all I'm convinced the 80 was much better in the sand.


Possible Reasons?
- I think the engine being more powerful in the 100 was a factor. Looking back at the tracks you could tell that the tires were spinning a lot with the 100, churning sand up and losing flotation when going up hill or when accelerating on flat terrain. Maybe giving it less gas may have helped but if you want to go fast enough to maintain momentum that's hard to do/judge. May be better with lower psi.
- ATRAC. The dang thing only came on once briefly. Most of the time nothing. I'm thinking it's because all 4 wheels were readily spinning so the system didn't see any big difference in wheel rpm. Bottom line is that ATRAC didn't do squat when I was getting bogged down and didn't help. Disappointing. Maybe normal given the design. Clear advantage to mechanical lockers, I think.


Overall, well, in fairness, the 100 did go nicely through a bunch of sand and dunes that most trucks would likely have had trouble with. It was fine most of the time. But no doubt that after being used to driving around in the 80 I had to curtail dramatically what I was attempting in the 100.

Next time, I'll try again with identical tire pressures but I think my overall impression is correct, at least for these 2 trucks.

 

[calamaridog]

This thread is worthless without pics

And what tires were you running?

And next time, lower the psi the same

 

[dclee]

The 80 is pretty much better than the 100 any ANY kind of terrain. That said...

The 100s biggest problem in sand, IMHO, is weight (all things being equal). Also, what size tires are on both trucks? And what tread patterns?

Also, for the most part, lockers do not help in the loose, soft stuff, they just cause you to dig down deeper. But, like most things in off-roading, that's not a rule, just a general observation.

Sorry we missed you! We had the gold 100 and white 80 next to Doug's (President NorCalDoug's) camper. But we were only there for the day, didn't even get to see Snook's new videos...

 

[FirstToy]

Eric,
Was this the 100 your wife was driving? The tires are quite small compared to your 80- in that the 80's tires are more "ballon" like than the low-profile tires on your particular 100.
I think Derek has listed the reasons pretty well. Also, the driver accounts for alot of the equation- sometimes it takes just a bit more of the skinny pedal to make the diff...

Also, did you have the cdl locked and in low range?

You do not want atrac to come on in the sand, it is not helpful and will just bog you down. With higher speed-or higher tire spinning, it is the VSC (or whatever it's called in the 100) that would activate. atrac would not operate under this situation.

 

[ShottsUZJ100]

You do not want atrac to come on in the sand, it is not helpful and will just bog you down. With higher speed-or higher tire spinning, it is the VSC (or whatever it's called in the 100) that would activate. atrac would not operate under this situation.

Yes...yes....the last thing you want is A-TRAC like the Sequoia, Escalade, and others have. TRAC kicks in an you sink in the sand and mud. The 100 won't cut throttle thank god.

I have three (well...2.5) guesses to your comparo:

1. PSI
2. Added weight (though I don't know your trucks' running gear)
2.5 Softer suspension (What do you all think about this effecting the traction)?

 

[Jim_Chow]

I'm with FirstToy. The 80 tires are on 16" wheels (taller sidewalls) while the 100 tires on the '03 are on 18" wheels (lower sidewalls), so a much smaller footprint. Combine that with more weight and you'd expect it to sink more. For the test to be more valid, I think you need to test the 100 with the same tires and less than 12psi to increase footprint size. Take both vehicles onto dry pavement w/ tires aired down, measure the footprint area under each tire. Then normalize by the weight of the vehicle so the pounds per square inch of tire area is the same for both vehicles with each tire done individually. Now repeat the test.

 

[ShottsUZJ100]

The 80 tires are on 16" wheels and larger than stock, right? So the 100 tires on the '03 are on 18" wheels (lower sidewalls), so a much smaller footprint. Combine that with more weight and you'd expect it to sink more. For the test to be more valid, I think you need to test the 100 with the same tires and less than 12psi to increase footprint size. Take both vehicles onto dry pavement w/ tires aired down, measure the footprint area under each tire. Then normalize by the weight of the vehicle so the pounds per square inch of tire area is the same for both vehicles with each tire done individually. Now repeat the test.

Oh yes. 16 vs 18" rims. That's a killer too.

 

[e9999]

The 80 is pretty much better than the 100 any ANY kind of terrain. That said...

The 100s biggest problem in sand, IMHO, is weight (all things being equal). Also, what size tires are on both trucks? And what tread patterns?

Also, for the most part, lockers do not help in the loose, soft stuff, they just cause you to dig down deeper. But, like most things in off-roading, that's not a rule, just a general observation.

Sorry we missed you! We had the gold 100 and white 80 next to Doug's (President NorCalDoug's) camper. But we were only there for the day, didn't even get to see Snook's new videos...

both were running 285s but the 100 had TerraGs which are wider and flatter so advantage to the 100 I think.

I beg to disagree about the lockers. I have had numerous experiences in the dunes where I would try and go up a dune face higher and higher adding one locker at a time. Definitely, they helped and were essential on the higher steeper stuff.

Hope you had a good time!

 

[FirstToy]

both were running 285s but the 100 had TerraGs which are wider and flatter so advantage to the 100 I think.

Eric,
I think with the big sidewalls, the 80 has the advantage. The 100 your wife was driving had very low profile tires from what I remember... flotation is the key. The 100 should do better in the sand I think- with the ifs and more power, it just needs the proper tire & psi to over come the 80 I think... next time try the 100 at 5-8 psi and see if that helps- airing down does wonders.

 

[e9999]

Eric,
Was this the 100 your wife was driving? The tires are quite small compared to your 80- in that the 80's tires are more "ballon" like than the low-profile tires on your particular 100.
I think Derek has listed the reasons pretty well. Also, the driver accounts for alot of the equation- sometimes it takes just a bit more of the skinny pedal to make the diff...

Also, did you have the cdl locked and in low range?

You do not want atrac to come on in the sand, it is not helpful and will just bog you down. With higher speed-or higher tire spinning, it is the VSC (or whatever it's called in the 100) that would activate. atrac would not operate under this situation.

I don't see how the 18" size tires would matter much over a 16". Surely it's the horizontal area that matters most. In this case the 100 had the wider squarer tires. Tread was a bit more aggressive on the 80 though.

Yes, CDL and Low.

VSC? going straight?

 

[e9999]

I'm with FirstToy. The 80 tires are on 16" wheels (taller sidewalls) while the 100 tires on the '03 are on 18" wheels (lower sidewalls), so a much smaller footprint. Combine that with more weight and you'd expect it to sink more. For the test to be more valid, I think you need to test the 100 with the same tires and less than 12psi to increase footprint size. Take both vehicles onto dry pavement w/ tires aired down, measure the footprint area under each tire. Then normalize by the weight of the vehicle so the pounds per square inch of tire area is the same for both vehicles with each tire done individually. Now repeat the test.

well, it's true that a lower profile tire would bulge less. But I don't think the difference was that great. Nothing compared to the night and day difference in overall traction. I'm a bit hesitant given the difference in psi, as I said, but my instincts are nevertheless pretty strong on this whole thing given how much I played in the sand... Plus as I said, I drove the 80 plenty with 20 psis and didn't have any trouble at all (until the time I fell in a deep hole and it took 12 psi to get out...)

 

[ShottsUZJ100]

VSC? going straight?

Nope. It won't kick in going straight unless you begin to drift.

 

[FirstToy]

I don't see how the 18" size tires would matter much over a 16". Surely it's the horizontal area that matters most. In this case the 100 had the wider squarer tires. Tread was a bit more aggressive on the 80 though.

Yes, CDL and Low.

VSC? going straight?

Sidewall, Eric. You have alot more 'balloning' w/ fatter sidewalls... I guarantee you have more flotation w/ the bigger sidewalls.

Atrac will not work with high spinning tires, at that speed the only thing to activate is the VSC. So that is to answer your question as to why the atrac did not activate. If it did, you were going pretty slow.

 

[e9999]

Yes...yes....the last thing you want is A-TRAC like the Sequoia, Escalade, and others have. TRAC kicks in an you sink in the sand and mud. The 100 won't cut throttle thank god.

I have three (well...2.5) guesses to your comparo:

1. PSI
2. Added weight (though I don't know your trucks' running gear)
2.5 Softer suspension (What do you all think about this effecting the traction)?

1. no, I did both at 20 psi
2. don't know. 80 had loads of stuff in back plus armor. 100 stock.
3. ?

 

[SINCITY100]

I have never been overly impressed with my 100`s "sand ability" ...

I think the weight (difference) is the major cause for its poorer performance, I am sure the right tire would help, but you just cant get around the heavyweight status of the 100

I hit the dunes regularly, I`m just more cautious with the 100 when considering driving through the deeper stuff..

Hmm.. Well, I guess its not THAT bad cause I still haven`t gotten stuck

 

[e9999]

Sidewall, Eric. You have alot more 'balloning' w/ fatter sidewalls... I guarantee you have more flotation w/ the bigger sidewalls.

Atrac will not work with high spinning tires, at that speed the only thing to activate is the VSC. So that is to answer your question as to why the atrac did not activate. If it did, you were going pretty slow.

yes, more bulge

atrac etc only works on tire speed differential I assume, so when all tires are spinning equally, it won't come on and help at all. Don't know about rpms limit.

I think the power was a big issue. I could really see sand churned up in the tracks and that's not good. Maybe i was too heavy-footed but I needed the speed more than in the 80.

 

[ShottsUZJ100]

1. no, I did both at 20 psi

I meant the difference. Drop to 12PSI would have helped.

 

[FirstToy]

No, with a bigger truck- you need MORE power, BIGGER tires and MORE gusto! Seriously tho, I think if you aired down the lo-pro tires more- you would not have had too many problems.
Next year, I'll drive her 100 and show you

 

[spressomon]

My 100 did much better at SnT than I thought it would have; never been in the dunes before last weekend. Maybe the 315's/4.88 with 12psi made the difference. Obviously it's not the vehicle of choice for dunes but it ran great.

 

[EL_3grab]

Weight and weight and weight... then the SF in 80 vs. IF in 100... Even when the CDL not engaged...

In the sand you want to distribute the weight on the largest traction surface you can, so the difference between 20psi and 12psi... might really help.

weight is the key on sand