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Old 8th August 2008, 09:40   #46
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Originally Posted by khan_sultan View Post
Can we get the 'same' effect in reality through the implementation method mentiioned above? Want to get some pro's and con's of this?
In order for this to work we first need to know which wheel is spinning. Lets say the right rear wheel is in the air and all power is going to it rendering the car immobile. If we were to apply brakes on that wheel the diff would then transfer power to the left rear wheel and the car would inch forward. Obviously you need to release the right wheel handbrake as you move forward so that as the wheel catches ground it too can power out.

The only draw back is the "electronics" here is your brain and the controlling action in your hands. If you know what you are doing it will work. I actually studied my 207 handbrake setup and will do this shortly once I find time and a spare handbrake lever for the cabin.

Look at it this way. When you are stuck and one wheel is spinning you need to get down and put rocks or logs under that wheel to get some traction. On the other hand while sitting in the car once you figure out which wheel is spinning you can simple brake it and allow the other to drive forward.

This has a high user involvement but I honestly believe it will work. Can you think of why it won't?

Oh and BTW this modification would cost at best Rs 1000

Last edited by DKG : 8th August 2008 at 09:42.
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Old 8th August 2008, 10:21   #47
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Obviously you need to release the right wheel handbrake as you move forward so that as the wheel catches ground it too can power out.
This is what I thought could be an issue in real situations and thought that the 'computer/electronics' would be able to control this better.

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The only draw back is the "electronics" here is your brain and the controlling action in your hands. If you know what you are doing it will work.
This is 'exactly' what I had in mind. At times we require split second decisions and a computer would do it better.

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Look at it this way. When you are stuck and one wheel is spinning you need to get down and put rocks or logs under that wheel to get some traction. On the other hand while sitting in the car once you figure out which wheel is spinning you can simple brake it and allow the other to drive forward.
Fully Agree.


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Oh and BTW this modification would cost at best Rs 1000
Yeah. Nothing to lose. Can't get better than this. "Even if" it doesn't work, the fun/novelty/DIY effort for such a mod is hard to beat for < 1000 bucks

How about the same contraption for front wheels that would have disk brakes.?
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Old 8th August 2008, 10:23   #48
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Look at it this way. When you are stuck and one wheel is spinning you need to get down and put rocks or logs under that wheel to get some traction. On the other hand while sitting in the car once you figure out which wheel is spinning you can simple brake it and allow the other to drive forward.
I was under the impression you feel that off-roading was about "connecting with nature".

Also the Braking Force required has to be higher than 2.5 times(Low- Ratio) engine torque, to effectively transfer torque to the other wheel.
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Old 8th August 2008, 10:26   #49
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How about the same contraption for front wheels that would have disk brakes.?
There's another thing I've been thinking about Shahnawaz. Technically a car with ABS and traction control should be ideal offroad. The traction control would automatically use the ABS system to brake the wheel losing traction. I think Toyota's FJ cruiser uses traction control for the front wheels and diff locks for the rear.

Ultimately though diff locks give you that sharp edged control in extreme offroading.

Its a simple mechanical mod Arka and being a mechanic at heart the idea appeals to me. You may be right in believing it won't work but the small cost of trying is worth the effort I feel.

Also doesn't "connecting with nature" imply not uprooting shrubs and breaking tree branches to get yourself out? I was also toying with the idea of making a small grip ladder which I can shove under the free wheel

Last edited by GTO : 8th August 2008 at 11:03.
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Old 8th August 2008, 11:04   #50
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Its a simple mechanical mod Arka and being a mechanic at heart the idea appeals to me. You may be right in believing it won't work but the small cost of trying is worth the effort I feel.

Also doesn't "connecting with nature" imply not uprooting shrubs and breaking tree branches to get yourself out? I was also toying with the idea of making a small grip ladder which I can shove under the free wheel
It is a simple mechanical mod, which we have tried out on a JEEP (rear axle) inspired by M&M Tractors.

Personally I prefer being mechanically inclined in the head and hands on.

Absolutely agree with the second point, its called "Tread Lightly"

However maximum trail damage is caused by unprepared/2WD trail vehicles, as they spin their wheels at every obstacle.

Regards,

Arka
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Old 8th August 2008, 14:11   #51
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This has a high user involvement but I honestly believe it will work. Can you think of why it won't?

Oh and BTW this modification would cost at best Rs 1000

Hi DKG,
This idea kind of dawned on me when I had gone to Jaisalmer. I first got bogged down in a marsh in the desert national park, and had to resort to stones under diagonally opposite wheels that were spinning (not to mention that my HT tyres are totally useless offroad - another 10K km to go before I get some decent ATs).

While easing the Scorp out of the chocolate churn, I kept it in 4L and resorted to quick pulls of the handbrake to give it a jerking action to give the rear wheels some bite, while swerving the front wheels side to side to get them to bite - and that actually worked.

I was wishing for diff locks at least for the rear, but don't know what size diff the Scorp uses - and also the ones I checked on the Net were over $1,000 a piece, shipping extra. Not worth it for the occasional offroad jaunt. Maybe cheaper to get a decent winch.

Let me know if you try this out - I may consider getting 2 handbrakes rigged up on the Scorp as well (with a clasp across both levers and release buttons so that they can be used equally when in city).
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Old 8th August 2008, 14:25   #52
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While there is no doubt in my mind that diff lockers would be great to have, as a matter of priorities, I would get a good winch first. You can get stuck even with diff locks. Diff locks or just LSD, a winch may get you out.
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Old 8th August 2008, 16:59   #53
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(with a clasp across both levers and release buttons so that they can be used equally when in city).
Right now I am just amazed how two people who have never met have had the same idea even down to details!! This is so uncanny. Its brilliant. Reminds me of a famous experiment by Japanese scientists where they confirmed that in any given species once a solution is found, simultaneously others think about it too!! Ever read the story of monkeys in Japan that learnt to wash potatoes in sea water before eating it? The same technique got applied by different troops on islands whereby there was no explanation how the peculiar habit was copied.

I will keep you updated when I get around to installing the independent links
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Old 8th August 2008, 17:15   #54
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Hi,
Pardon my ignorance,but i have a small question for 4x4 guru's,
been browsing this thread and many 4x4 treads according to these Mahindra vehicle's dont have diff locks or LSD so how do the wheels get the traction in a 4x4 situation, for the front wheels we have the locking hubs but what about the rear wheels.
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Old 8th August 2008, 19:53   #55
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Hi,
Pardon my ignorance,but i have a small question for 4x4 guru's,
been browsing this thread and many 4x4 treads according to these Mahindra vehicle's dont have diff locks or LSD so how do the wheels get the traction in a 4x4 situation, for the front wheels we have the locking hubs but what about the rear wheels.
Friction, just like two wheel drive vehicles except that 4 wheels gives you twice the friction roughly. The difference is amazing even without limited slip or diff locks. Front locking hubs are not differential locks and do not give traction. Their purpose is to stop the front axle, propeller and differential from turning while in TWO WHEEL drive so as to cut down wear and give better fuel average.
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Old 8th August 2008, 20:04   #56
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Right now I am just amazed how two people who have never met have had the same idea even down to details!! This is so uncanny. Its brilliant. Reminds me of a famous experiment by Japanese scientists where they confirmed that in any given species once a solution is found, simultaneously others think about it too!! Ever read the story of monkeys in Japan that learnt to wash potatoes in sea water before eating it? The same technique got applied by different troops on islands whereby there was no explanation how the peculiar habit was copied.

I will keep you updated when I get around to installing the independent links
Thirty years ago an experiment with rats was done. Identical twin Rats were separated, some in London some in New York. The rats in London were set into a labyrynth, a maze, and timed as to how fast they found their way to food at the other end. Their identical twins in New York learned to solve the same maze much faster than other rats in New York that were not related.

None of the rats had diff locks or dual brakes. (bringing it back on topic, boss) Mods, please combine with last post if you want.

Last edited by DirtyDan : 8th August 2008 at 20:07.
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Old 10th August 2008, 22:47   #57
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Just got the delivery of 'lockers'. Initially had planned for an LSD but got the LockRight Automatic Positive Locking Differential instead.

Can't wait to get the install done and get 'off the road' :-) Have started a separate thread for the install of the same on my Gypsy.

Gypsy on Drugs


Cheers,
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Old 26th October 2009, 16:22   #58
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Perhaps at this point we could understand how LSD works and the various tech used? I would have to read up as I know very little beyond that they basically creates some form of bind between the axle half shafts
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Old 26th October 2009, 16:34   #59
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Even I am hazy about the exact working of different LSDs. I understand the behavior and working of viscous LSD. I understand the behavior of torque sensing LSD, but not the working. Rest I don't know.
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Old 26th October 2009, 16:41   #60
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This whole subject of drivetrain tech and traction is so deeply interesting. How I wish I had studied automobile engineering. The first time I took a differential apart I was so impressed by the simple yet ingenious tech of using the planetary spider gears. Its so brilliant and a delight to watch in action !
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