sleeoffroad
Supporting Vendor
When are you going to get it, these poeple don't race on tracks.
TrueTrac Limited Slip in the front?
- Thread starter alkaline747trio
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I am learning a lot about my 100 posts.
I think I've finally seen the light? Time will tell though. 
that is just a stupid reference in trying to make a point either way on this subject. I don't see a lot of Hummers period. I don't see a lot of Hummers on any trails. I don't see any Hummers driving alongside me
No, not exactly like either because as Spike indicated the driver chooses the behavior specific to the context.
well, maybe in your specific conditions of marginal traction, fairly uniform substrate, on a track. But I invite you to drive across Montana, South Dakota, etc in conditions where the vast majority of the road surface is completely dry interspersed with occassional patches of solid frozen ice, slush, water or whatever. Try to make simple lane changes or avoidance manuevers under these conditions. See how maybe a slipping front tire could engage that at an inappropriate time? These are reasons most folks have lock-out hubs and an "auto locker" up front - it's just not worth the risk.
that is just a stupid reference in trying to make a point either way on this subject. I don't see a lot of Hummers period. I don't see a lot of Hummers on any trails. I don't see any Hummers driving alongside me
The point is that it's a production truck running a gear type LSD in the front diff. It matters not if it's trail or road. I find claims that a torsen is 'unsafe' in the front axle of any truck to clearly misunderstand how the differential operates.
You obviously haven't been to Steamboat's Ice Track.... I also have to drive across the country to get to Steamboat the second week of Feb every year. In that 15years, I've seen mixed mu all the time! Again, this is misunderstanding how a gear type LSD works. A torsen type LSD will allocate all the torque up to the TBR of the differential BEFORE wheel spin occurs. Post 1 was referncing a tru trac, as was I, that's not a detroit ezlock or traction lock, a True trac is a torsen type LSD. If the wheels are sliding with torque applied the diff is already at it's maximum torque bias ratio.
Vehicle Dynamic Chaulk Talk:
In lane changes or avoidance maneuvers, how much torque trasnfer do you think you have? Scenario, you are driving down the road (all diffs open, Trutrac is at 50/50), you need to make a maneuver to avoid something. If during that maneuver the front tire slip is equal, the trutrac won't change torque allocation, whip the wheel back and forth, it just won't. If during that meneuver, one tire slips more than the other, the drive allocation goes to the wheel with better traction. If you were at a 50/50 state prior, the most the torque can shift is 30% to the wheel with more traction. What this means is the wheel with less traction also has 30% less torque applied to it. With an open diff, the steering wheel with the least traction will still have 50% torque applied to it.
I'm comfortable with a torsen type LSD in that scenario, it appears to me that you are reducing the torque to the steered wheel with the most slip. I miss the *bad* part of that.
ST
Come on Sumotoy....not this again. You started this stuff in the 100 forum. I didn't want to argue with you so I dropped it.
You are preaching to the choir. These guys in this forum....especially Slee, know more about what's better or best in an 80 series than you or I probably ever will. (Especially me)
If you'd like to start a thread named "Which traction devices are best for racing at Steamboat" then start-one. Meanwhile...I wouldn't even consider running any kind of LSD in the front of any 4WD SUV I own. With and open/locked combo (or even better...add in traction control like the 100-series has to the mix) you get the best of everything for 4-wheeling. We're not talking ice racing. Get it my friend?
- Thread starter
- #47
Ok, seems like everyone but SUMO thinks it's worthless, I agree with some points SUMO has, it WILL do what it is suposed to, and increase traction and force a wheel with traction to spin.
BUT...
My truck will handle goofy.
In the most extreme situations, it wont be all that helpful.
It's complicated.
For the record, I PLAN TO LOCK THE REAR BEFORE OR AT THE SAME TIME, THE LSD IS JUST A CHEAPER ALTERNATIVE TO AN ARB!!!!
I guess I'll just remain open in the front untill I can afford an ARB, BUT STILL PUT AN AUSSIE IN THE REAR.
BUT...
My truck will handle goofy.
In the most extreme situations, it wont be all that helpful.
It's complicated.
For the record, I PLAN TO LOCK THE REAR BEFORE OR AT THE SAME TIME, THE LSD IS JUST A CHEAPER ALTERNATIVE TO AN ARB!!!!
I guess I'll just remain open in the front untill I can afford an ARB, BUT STILL PUT AN AUSSIE IN THE REAR.
Come on Sumotoy....not this again. You started this stuff in the 100 forum. I didn't want to argue with you so I dropped it.
You are preaching to the choir. These guys in this forum....especially Slee, know more about what's better or best in an 80 series than you or I probably ever will. (Especially me)
If you'd like to start a thread named "Which traction devices are best for racing at Steamboat" then start-one. Meanwhile...I wouldn't even consider running any kind of LSD in the front of any 4WD SUV I own. With and open/locked combo (or even better...add in traction control like the 100-series has to the mix) you get the best of everything for 4-wheeling. We're not talking ice racing. Get it my friend?
When it comes to 4 drive wheels, not sure it matters what you attach it to. Steamboat is a mixed low mu surface that exagerates handling by raising the HP:cf ratio in a controlled enviornment. I always remind participants there is no racing at my Event. Not a single timing device or award present. No studs allowed, egos and misunderstandings of drive systems get punted quickly.
I'm not speaking to ice racing, I speak to awd vehicle dynamics. When I can't get folks to lock the center diff and try driving it, that's just plain misunderstanding of vehicle dynamics. When I hear "unsafe" in terms of these dynamics, I feel qualified to at least question the logic.
I don't see traction control as the best of everything, unless it can cross the center axle. The 100 doesn't do that. And without engine power reduction in the traction control circuit, the torsen has the advantage, becaue it allocates torque *before* wheel spin. Add traction control to a torsen diff.... Now you're talking. It's one of the mods I do in my shop actually.
I only seek to have more experience. I temper 'extreme' performance with a more moderate position. I personally would rather focus on debunking the 'unsafe' vehicle dynamic scenarios than debate a locker vs a LSD.
ST
FJBen
SILVER Star
So here's what I'm getting:
LSD better than locker...
SC better than turbo...
So we should S/C and LSDs in our cruisers to win in the Steamboat Ice race???
hell anyone want two e-lockers? I can't stand full 100% lockup anytime I want it...I'd rather something work whenever it wants and not when my tire is in the air, because lifting a tire is WAY too extreme of wheeling for me! 
btw: Aussie the rear, ARB the front...when you have time/money
LSD better than locker...
SC better than turbo...
So we should S/C and LSDs in our cruisers to win in the Steamboat Ice race???
hell anyone want two e-lockers?
I can't stand full 100% lockup anytime I want it...I'd rather something work whenever it wants and not when my tire is in the air, because lifting a tire is WAY too extreme of wheeling for me! btw:
Aussie the rear, ARB the front...when you have time/money
Sumo isn't the only one who disagrees with those who say the LSD is worthless for wheeling. Like I stated in my previous post, I have the TruTrac in my 4Runner and it beats the hell out of an open diff. The trick is learning how to use it, and applying the brake at the right moment is somewhat counter-intuitive, but it does work. You can "turn off" the TruTrac is you have manual hubs -- simply unlock them. Those of us who run manual hubs are very accustomed to locking/unlocking them and I never have them locked when I not using 4WD, so the bitching and blanket statement about the LSD being unsafe for regular driving is just completely bogus.
Now -- that said -- the TruTrac may not be a very good option for the 80s since we drive full time 4WD vehicles. Converting to manual hubs and converting the drive train from full time 4WD to regular 4WD is way outside of my experience and I doubt it would be worth the effort or expense. I realize that the OP is obviously asking if the TruTrac would be a good option for his 80, and I have to agree with the majority that it's probably not a good plan. But to say the LSD in 4-wheeling application, overall, is worthless just isn't true.
Ed
Now -- that said -- the TruTrac may not be a very good option for the 80s since we drive full time 4WD vehicles. Converting to manual hubs and converting the drive train from full time 4WD to regular 4WD is way outside of my experience and I doubt it would be worth the effort or expense. I realize that the OP is obviously asking if the TruTrac would be a good option for his 80, and I have to agree with the majority that it's probably not a good plan. But to say the LSD in 4-wheeling application, overall, is worthless just isn't true.
Ed
I figured a 4R driver or many would step up... Thanks Ed, and I did acknowledge that it's best used with lockouts early on. That said, it doesn't *have* to be anymore because T-T will and can change the bias ratio to be lower in the front applications.
Now that everyone's all in arms, I'll put forth my thoughts on the downsides of a tru-trac. First, it's not considered a good diff for high torque application, so if 'racing' or some other high torque event, it has a tendency to break it's basket. Second, under sudden low torque to high torque events it tends to also break it's basket, because the torque biasing helix gears will slam into the basket with force enough to break the basket. This is usually a 'in flight' type event (at speed jumps, not crawling). Third, since it IS not a coupler, the two driveshafts are connected all the time. In high cf conditions this will and can cause an addition of understeer under turns, but it's linear (and less effect at lower engine torque), unlike a clutchpack or autolocker. So, it is transparent to the driver, IMO, it just understeers more than when unlocked. The other side of that, is that in low cf conditions, it will bias torque away from the steering wheel with the most slip.
A trutrac is not an autolocker, so whomever put that forth was in error.
I believe there is a lot of misunderstanding on awd systems in general. A lot more in terms of vehicle dynamics, 'danger' and 'unsafe' comments regarding a trutrac front application seem a bit far from the reality of a gear type LSD device. IME.
ST
Now that everyone's all in arms, I'll put forth my thoughts on the downsides of a tru-trac. First, it's not considered a good diff for high torque application, so if 'racing' or some other high torque event, it has a tendency to break it's basket. Second, under sudden low torque to high torque events it tends to also break it's basket, because the torque biasing helix gears will slam into the basket with force enough to break the basket. This is usually a 'in flight' type event (at speed jumps, not crawling). Third, since it IS not a coupler, the two driveshafts are connected all the time. In high cf conditions this will and can cause an addition of understeer under turns, but it's linear (and less effect at lower engine torque), unlike a clutchpack or autolocker. So, it is transparent to the driver, IMO, it just understeers more than when unlocked. The other side of that, is that in low cf conditions, it will bias torque away from the steering wheel with the most slip.
A trutrac is not an autolocker, so whomever put that forth was in error.
I believe there is a lot of misunderstanding on awd systems in general. A lot more in terms of vehicle dynamics, 'danger' and 'unsafe' comments regarding a trutrac front application seem a bit far from the reality of a gear type LSD device. IME.
ST
Lots of theory on this post. I have run an True Trac in the front of an AWD XJ with a Detroit in the rear. This is a great road setup and moderate core setup, especially for bad weather. Simply amazing in the snow, never had anything better (including ARB/e-locker that are spools when locked). Not squirrely or anything else - it's a gear driven LSD and not clutch like an Auburn.
Offroad, they do help, even in moderate rock crawling, but the guys with just rear lockers will go everywhere you go with a rear locker and front LSD. Given our author of this thread is looking at 37" tires, a) a true trac is nowhere near strong enough, and b) you simply cannot go without a dual locked setup for hardcore wheeling - you will be at such a disadvantage that it will keep you off the trails that your 37's where slapped on to run.
So is this setup a waste of money? Not at all depending on your usage. If you aren't super hardcore and don't want to mess with ARB's (cost/complexity) then a rear automatic locker/front True Trac is an outstanding setup on an AWD rig. You have nothing to mess with and great all terrain capability.
For somebody building a trail only rig like Alkaline, any limited slip is complete and total waste of your money.
Nay
Offroad, they do help, even in moderate rock crawling, but the guys with just rear lockers will go everywhere you go with a rear locker and front LSD. Given our author of this thread is looking at 37" tires, a) a true trac is nowhere near strong enough, and b) you simply cannot go without a dual locked setup for hardcore wheeling - you will be at such a disadvantage that it will keep you off the trails that your 37's where slapped on to run.
So is this setup a waste of money? Not at all depending on your usage. If you aren't super hardcore and don't want to mess with ARB's (cost/complexity) then a rear automatic locker/front True Trac is an outstanding setup on an AWD rig. You have nothing to mess with and great all terrain capability.
For somebody building a trail only rig like Alkaline, any limited slip is complete and total waste of your money.
Nay
- Thread starter
- #54
Nay, sounds good...and is what I have gathered. This rig is gonna be trail only in the next 2 years, but everything has to be done with a budget. If the planned 37's are gonna explode this LSD and end up costing me more money, then I'll pass.
I can not see how this would be completely worthless now that I think about it, but the benefit is nill and the possible side affects could be worse than the problem it helps.
I guess another grand is to be added to the total budget for an ARB in the front, but that can always wait. Thanks for the help guys.
I can not see how this would be completely worthless now that I think about it, but the benefit is nill and the possible side affects could be worse than the problem it helps.
I guess another grand is to be added to the total budget for an ARB in the front, but that can always wait. Thanks for the help guys.
Spike, do you understand that a limited slip differential is not a locker, nor does it behave like one? Have you ever used a True Trac in a front axle? I had Warn lockout hubs on my old XJ with a True Trac and I chose to drive it with the hubs engaged because of how much better it drove. Why do you need to unlock a gear driven limited slip differential?
Why is it not safe? Ever used one?
Nay
Jason Andrews
Modaholic
Nope, just makes them more challenging
Ever been to Carnage Canyon?Well, said though.
Yea it can wait, first try to Out-Wheel some other junk With locker s and have more bragging rights!
IMHO I would find the rigs limit with open diffs and good lines and a little extra momentum before you spend the extra $$$ for the lockers.
J
- Thread starter
- #57
Nope, just makes them more challenging
Well, said though.
Yea it can wait, first try to Out-Wheel some other junk With locker s and have more bragging rights!
IMHO I would find the rigs limit with open diffs and good lines and a little extra momentum before you spend the extra $$$ for the lockers.
J
I already do that with slick 33's
Wow Ben, it was like a light shining in on a pile of stinky poo,
Thanks for bringing this sucker to a close
The rest of you go smoke your crack pipes while wheeling your Audis on ice?
Thanks for bringing this sucker to a close
The rest of you go smoke your crack pipes while wheeling your Audis on ice?
i had a trutrac in the front of my t100 i know its not the same as an 80 but it was my daily driver to the trutrac worked great in the sand sucked in the mud and on hill climbs and was unpredictable on snowy roads unless the snow was 6 inches deep or more then it was fine i also ran an eaton lsd in the rear and when you got the frame flexing and tires lifting they were hit or miss for engaging way to much dancingwiyh the pedals for me and after running an80 with lockers iwouldn't go back to a lsd they just don't compare
You actually sound like the best build for you would be losing AWD, lockout hubs, and just putting an automatic locker up front. You get strength, reliability, and function in exchange for AWD. Of course you'd want 2wd low for the stretches between obstacles. And that's not a budget solution in any case.
Are you doing a rear locker? I'd just Aussie lock the rear and do the rest of the build and see how it goes. The front will make all the difference in the world, but you can get into a ton of trouble on 37's with a rear locker for sure.
You might keep an eye out for e-locker 3rd members and then rig up a cable actuator. Might be a deal you can score. Of course, 37's may be pushing the e-locker as well in terms of strength, but for your build I just think you'd be sorely disappointed in the True Trac, durability notwithstanding.
Or put that money into 5.29's - that is going to be more important than any front diff on 37's. Quite honestly, I'd do the gears before any lockers. 5.29's and 37's will take you far indeed, and when you get stuck it won't be as bad as if you were locked.
Nay
