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Old 3rd December 2008, 14:26   #91
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You can drive comfortably upto about 100 kmph. The vehicle construction itself will constrain you not to go above 80 kmph. Armada with XDP4.90 engine (same as yours) has the same axle ratio of 5.38:1. But do not expect the vehicle to be very fast on tarmac, that's all.

Best regards,

Behram Dhabhar
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Old 3rd December 2008, 15:16   #92
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Quote:
Originally Posted by DHABHAR.BEHRAM View Post
You can drive comfortably upto about 100 kmph. The vehicle construction itself will constrain you not to go above 80 kmph.
@ Dhabhar Behram: Sir, why is it that we cannot go over 100kph? Can you explain the vehicle construction bit? I'm a little foxed here!
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Old 3rd December 2008, 15:38   #93
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Dear Vikram - Road speed in kmph = Engine rpm * 2 * 3.1416 * dynamic rolling radius of the tyre * 60 whole divided by gear ratio * axle ratio * 1000. The higher the axle ratio, the higher the engine speed for the same road speed. This means that for a wheel rpm of 1000, for a 5.38:1 axle ratio vehicle, the propeller shaft rpm will be 5380. If the same vehicle is now fitted with a lower axle ratio like say 4.88:1, then it will mean that now for a wheel rpm of 1000, the propeller shaft rpm will be 4880. If you consider both cars in 4th gear (1:1), engine rpm of the first car will be 5380 whereas enginer rpm of the second car will be 4880. Therefore, the wheel force on the ground of both cars will be different. How different? It depends on wheel force "F". F = a+bv2(square, not two)+mdv/dt where a = coefficient of rolling resistance, b = coefficient of drag, m = inertia (unladen weight + 150 kg) and dv/dt = acceleration, means rate of change of velocity with respect to time. In case of the 340, the end result of all this is that the 5.38 delivers better driveability offroad because the engine's power delivery curve fits into the higher axle ratio slot.

Vehicle construction - low wheelbase to track ratio, higher centre of gravity and high roll centre does not lend itself well to high speed use. The intention is not to use high speed but to use low end grunt.

Please acquire and read the Bosch handbook on Automobiles. It is like a bible for cars. All above is elementary.

Hope it clarifies.

Best regards,

Behram Dhabhar
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Old 3rd December 2008, 16:52   #94
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Thanks so much Behram Sir, I got a idea of the stuff. I have PMed you on modifying my 540 and need your inputs there too. Thanks
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Old 3rd December 2008, 17:07   #95
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headers,

Doing up your MM540 secretly? not fair man, let we ordinary people also know what best can be done to MM540:-))))))
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Old 4th December 2008, 12:29   #96
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Thanks Behram Sir,

That bit was very enlightening .

By the way whats the Bosch book Name. Will try to get a copy of the same

And where can I get the parts catalogue and vehicle description for my Mahindra CJ 340 DP 4WD

With Best Regards

Babu
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Old 4th December 2008, 13:32   #97
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Quote:
Originally Posted by Baburajs View Post
Thanks Behram Sir,

That bit was very enlightening .

By the way whats the Bosch book Name. Will try to get a copy of the same

And where can I get the parts catalogue and vehicle description for my Mahindra CJ 340 DP 4WD

With Best Regards

Babu
Please also let me know the name of the publisher and the name of the the book. I would try to buy it from here in Delhi
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Old 4th December 2008, 13:53   #98
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Bosch Handbook - go into any good technical / engineering college bookstore and ask for "Bosch Handbook". It costs around 5000 rupees. It has a dark blue cover. Normally the guys do not have it but they will get it for you on order.

Best regards,

Behram Dhabhar
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Old 4th December 2008, 14:18   #99
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Quote:
Originally Posted by harjeev View Post
Please also let me know the name of the publisher and the name of the the book. I would try to buy it from here in Delhi
It is called as "BOSCH Automotive Handbook" and ISBN is 0-7680-1513-8. 7th edition is the latest. I guess it should be available in major book stores like Gangarams in bangalore.

Publisher is Robert Bosch GmbH.

Last edited by star_aqua : 4th December 2008 at 14:19.
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Old 15th December 2008, 13:21   #100
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Ok,

Now I was searching for changing my back differential in my quest to change my jeep to 4WD. I have already sourced the fron differential and TCase. I have got a back differential which is free floating but the length of the axles and the housing is about 3 inch more than the front housing. That is the back wheel will jut outside by about 1 1/2 inch when compared to the front wheel. Will this cause any problem. Or is there any advantages. Please advice.
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Old 16th December 2008, 14:37   #101
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Can anyone reply on this. Wanted to move the restoration fast.
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Old 16th December 2008, 15:13   #102
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Your question has been discussed here.

http://www.team-bhp.com/forum/4x4-of...les-cj340.html

Not sure whether it has been answered conclusively.
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Old 17th December 2008, 13:52   #103
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As you suggested the discussion didnt end conclusively. What will happen if i use the 51 MM540 axles for a CJ340 at the rear and the original CJ340 axles and housing at the front.
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Old 17th December 2008, 18:09   #104
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Dear Baburajs - WHY DO YOU WANT TO CHANGE AXLE? Can I please understand once and for all why 4WD guys always talk of changing axles? Kindly revert.

Best regards,

Behram Dhabhar
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Old 17th December 2008, 20:04   #105
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Quote:
Originally Posted by DHABHAR.BEHRAM View Post
Dear Baburajs - WHY DO YOU WANT TO CHANGE AXLE? Can I please understand once and for all why 4WD guys always talk of changing axles? Kindly revert.
It is simple Behram. None of us non-classic CJ/CL340 or CJ3X owners really run stock tyres, in fact we don't even know stock tyres specs. Most of us are running oversized tyres, and often with lifted chassis. This makes highway manners pretty dicey, with high bodyroll and lack of handling. Also the wider tyres scrape the leaf-springs and allow less articulation by hitting the inside of wheel well. In addition the 48 inch axle doesn't give any option to switch to full-floating or to add LSD.

By switching to 51 inch axle housing people hope to get better handling, less bodyroll, better articulation, better turning radius and it also opens up posssibility of adding LSD and full floating in the rear.
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