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Isuzu Trooper

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Comments

  • I have had DirectHits in for 40K miles so far.
    I am sorry about the double spaced paragraphs in the previous post. I only spaced them by one in the editor.
    Thank You BoxTrooper
  • sbcookesbcooke Posts: 2,297
    That they aren't making any new troopers, is it time we decide what the best year/model ever was? Is the 2002 the best adding the last 10 years of enhancements or is it the earlier models with the 4.55:1 axle ratio?
  • paisanpaisan Posts: 21,181
    If you get a chance, jump into the Trailblazer v Rodeo v. mountaineer topic in the SUV section. Lots of Troopa haters in there :(

    -mike
  • Those fellars aren't looking for a rig. They're looking for a minivan. They want a 3rd row seat and 0-60 times of a porsche. God for bid they get a scratch in the side paneling from a trail. Leave them to there minivans.
  • paisanpaisan Posts: 21,181
    :) Tis true, but the trooper is the best of both worlds! :) We must convert the non-believers! :) Haaaaaa

    -mike
  • bsmart1bsmart1 Posts: 377
    That's quite at testimonial on the DirectHits system. Too bad it can't be used on the newer Troopers. Looks like they would come up with a version to make it work. All that talk of power boost and better gas mileage has got me itching to buy a set.
    Happy Trooping!!
  • I was just told that the borg and warner / TOD unit is the same as unit used int the Explorer sport trac. Ids this true?
  • sbcookesbcooke Posts: 2,297
    I don't think so. borg and warner manufacturs a lot of different transfer cases. Many of them use electromagnetic clutches and automatically tranfer power back and forth, etc. The new ford explorer case will route up to 100% of the power to the front, rather than 50% as in the trooper. I think if you look around, you will find that a lot of b/w cases are similar, using the similar components, and having similar function, but not the same.
  • paisanpaisan Posts: 21,181
    B&W makes all different T-cases. They make they system in the MDX which is nothing like the TOD unit we get.

    -mike
  • OK so TOD can split torque between front and rear axles 50/50. So if my rear tires were on ice (virtually zero torque) and the fronts on pavement (can handle loads of torque), how much power does the front get? This is a silly question, but I've been wondering for a while. Is it truly a 50/50 split, or can the TOD go from 0/100 to 99/1?
  • paisanpaisan Posts: 21,181
    Torque split on the TOD unit ranges from 0/100 to 50/50. You will always get at least 50% power to the rear axle. The rear has an LSD so the power can then be split 25%/25% if need be across the rear axle. I've been thinking of putting in an LSD in the front to split the torque across the front axle as well.

    -mike
  • so if the rear wheels are slipping on ice and getting virtually zero torque sent to them, then the front is getting virtually zero torque as well even though it could handle more? Like an open diff then. If TOD could lock the front and rear axles together (like part-time system or TOD's low range does this), then torque split could be 99/1. I know this is a silly little question, but I guess what I'm asking is whether or not TOD can lock the front and rear together or is it always like an open diff?
  • paisanpaisan Posts: 21,181
    If the rear is slipping, you are still getting at least 50% of the engine torque going to the rear axle. For instance:

    lets say you are reving the engine to the peak torque of 230lbs and the rear wheels are on a frictionless surface, you would have 230/2 = 115lbs of torque going to the rear wheels or 57.5lbs to each rear wheel if the LSD activates.

    In the front you would have 115lbs of torque going to the front axle, with 115lbs of torque to either the left or right side wheel in the front.

    The TOD system works like an anti-open diffy, rather than put the power to the slipping wheel or the wheel with the least resistance, it puts it to the axle with the most resistance. There is no way to get TOD to act like a traditional Part-time 4wd in Hi-mode and lock it at 50/50. In Low range it locks the torque in at 50/50.

    -mike
  • Yes the engine might make 230 ft/lbs, but what if the rear can only handle 2 ft/lbs (driving on slick ice) before it slips. Once the rears slip from a static friction (rolling) that allows 2 ft/lbs to a kinetic friction (spinning) which allows 1.5 ft/lbs then the front is only getting 1.5 ft/lbs if the rear were spinning on my theoretical low friction ice. When you rev the engine, the torque that the engine makes doesn't go to the ground, but goes into rotational momentum of the tires (spinning).

    A part time system locks the speed of the front drive shaft and the rear drive shaft together. A part time system can have zero power delivered to the rear axles (spinning on ice) while the front is on pavement allowing 100% of the engine torque to go to it.

    Don't get me wrong Paisan, I'm just curious as to the limitations of TOD, or if there are any. I know you still can lock it down into low range and all.

    I know on paper TOD can split 50/50, but that would be bad if the rears were on ice and the front's weren't (yes an uncommon situation). The front tires wouldn't get any power. Are you up for a little testing??? Floor it and see if it will take off in the above mentioned situation, or whether it's spinning the rears on ice for a bit.
  • paisanpaisan Posts: 21,181
    No the split doesn't know where the torque goes. It only knows that 50% of it is going to the rear axle. In your example of ice you are saying only 2ft/lbs are going to the ice and 2 ft/lbs are going to the front tires. In math/physics you can't have the other 226lbs dissappearing into thin air! :)

    Basically the way the TOD works is that it uses speed sensors to compare the rear drive shaft speed to the front driveshaft speed. If the rear is spinning faster than the front it will change the clutch pack to allow more torque to go to the front driveshaft. If they are both spinning at the same speed, then 85% goes to the rear and 15% to the front. If the rears are on ice, it will put 115lbs of torque to the rear axle, and the rear wheels will spin away that 115lbs of torque and the front will get 115lbs of torque to apply to the ground or spin if the front axle is on ice as well.

    The TOD doesn't work like a Viscous coupling that will always strive for a 50/50 split. In general vehicles with a center V/C cannot lock in 50/50 (although my '88 subaru XT6 does have a center air-locker) and generally don't have low range either.

    A system that puts 100% front or rear when necessariry would be nice, but I'm sure there was a reason the B&W engineers set it up to only go 50/50. Essentially when you are spinning the rear wheels, you have a 50/50 torque split and thus have the same split as a center locking diffy.

    -mike
  • paisanpaisan Posts: 21,181
    I've actually done the tests at my place upstate in the snow. I drove up to a snow bank and had the rears on ice, fronts in snow. Once I got the rears spinning the front would pull up the snow bank, using the 50% torque to the front. The rears kept spinning though. I also tried all 4 on ice, that was cool 1 front and 2 rear spinning.

    I only wish I had a front LSD so that it would be less likely to be stuck.

    -mike
  • bluedevilsbluedevils Posts: 2,554
    #3088 - great post. Troopers are not invincible, and we need to keep that in mind.
  • bluedevilsbluedevils Posts: 2,554
    I agree with your thinking about the typical Trooper owner being more knowledgeable/detail-oriented about his/her vehicle than the typical Explorer owner. However, this could be just one of many reasons why Explorers are in the news for tread-separation-induced rollovers and Troopers aren't. Other reasons: fewer incidents because very few Troopers sold vs. high-volume Explorer sales, tires used on Troopers separate much less often than tires (Firestones) used on Explorers, etc.
  • bluedevilsbluedevils Posts: 2,554
    My local Target store always had the lowest Mobil1 prices around. It was $3.04/qt for quite a while, then dropped to $2.94 for a few months in mid-2001. Then this particular Target location increased its price to $4.49/qt. All the other Targets in my area (southeast Michigan) were always $4+ per quart. Most other stores (Wal-Mart, Kmart, etc.) were $4+ as well. I'm not sure why the one Target store was so much cheaper than everyone else. Until now, I thought this phenomenon was unique to the store near me but fiveharpers has seen the same thing near him (Virginia). Strange.

    I'm glad I loaded up @ $2.94/qt. My local Sam's Club also has Mobil1 cases for $21.98/qt.
  • bluedevilsbluedevils Posts: 2,554
    St. Charles Isuzu is definitely the place to order them. Free UPS shipping. 800.727.8066. Mention ITOG or the St. Charles web site (www.stcharlesauto.com) and you'll get 15% off Isuzu list price. On top of that, the filters are frequently on sale below that price. You'll always be well below 5 bucks each, and under 4 bucks when they're on sale.
  • bluedevilsbluedevils Posts: 2,554
    The Explorers roll over when tire tread separations occur. This seems to be made more likely when tire pressure is below a safe level. Ford specified 26psi (and Firestone 30psi - or was it the other way around?), which turns out to be too low to be safe, according to most folks.

    My contention is that the Explorer is not defective. Their recommendation on tire pressure was too low, but the vehicle itself does not seem to be unusually tippy.
  • paisanpaisan Posts: 21,181
    The problem is that they become tippy with 30psi in them. It was a catch 22 for them. If ford say put in 30psi, then they have a tendancy to roll. If they leave it at 26psi, they hope the tires don't heat up too much and the lower CG and more rubber help keep em from rolling, if there is tire separation, then they blame firstone. In this case it looks like their plan backfired though :)

    Even with tread separation, and blow-out a vehicle should not roll over. There have been no cases of rollovers on the troopers in the real world attributable to the rollover-test that CU claimed. Funny how CU never rolled an explorer, yet there are tons of real world rollovers, in their test they roll a trooper but there are no real world cases of rollovers in that situation... :)

    -mike
  • Let's say that the wheels can only handle 100 ft/lbs total. You have 130 ft/lbs left at wide open throttle (WOT). It goes somewhere, but not to the ground. It goes into the engine revving higher (rotational momentum +excess heat) It goes into the torque converter (fluid energy storage+heat) and the transmission (more rotational inertia). It goes into the axles and differntials and tires (rotational inertial again). The engine then hits redline where it's fuel is cutoff (not completley) so that the engine doesn't blow up. You are no longer at wide open throttle and have to be at part throttle not making 100% of your engines torque. So the moral of the story is the torque does go somewhere, just not to the ground :(

    TOD still is an awesome system :)
  • Hold on to that thought. I am going to go get my PHD in mechanical engineering so I know what the he@$ is talking about.
  • Sorry bout that
  • paisanpaisan Posts: 21,181
    Yes I agree it is lost in the driveline, but X torque coming out of the tranny gets split 0/100 up to 50/50, it can't go anywhere else, so if the back is slipping it is still only going to get 50% of the torque and 50% of the X torque will be in the front. I wish the system could do a full range from 0/100->100/0 but it isn't in the cards, I guess because at 50/50 split it acts like a locked diffy, they figure no need to put more than that much power to the front?

    -mike
  • tidestertidester Posts: 10,109
    Just an addendum to dielectric's comments:

    Torque and power are not the same thing! You can apply a torque but no work is done unless something moves. Power is work delivered per unit time.

    tidester
    Host
    SUVs
  • acts as an open diffy.

    0/100->100/0 acts as a locked

    Good info.
  • gpm5gpm5 Posts: 785
    I thought an open diffy delivered all to the wheel slipping, hence the situation where one rear wheel spins on ice while the other stays still.

    In terms of the TOD vs 4WD Lo, I seem to recall last winter where 4WD Lo delivered a better low speed torque to all wheels in snow (especially while backing up a trailer through snow)than did the TOD. On a slippery surface the TOD tends to spin the wheels from a stop first, before splitting the torque.
  • An open diff is a 50/50 split. If one wheel starts spinning it provides 'virtually zero torque' to the ground. The same amount of 'virtually zero torque' is sent to the other wheel too. A spinning tire is worse than a rolling one due to static (rolling) and kinetic (spinning) friction.

    I know it's all so confusing. That's why I wanted to know if TOD was truly 50/50 like an open diff or if it can actually lock them together like a part time system. I thought Isuzu might have said it can provide a 50/50 split because the public thought that was the best you can do. Oh well...
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