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Old 26th May 2010, 12:19   #61
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Originally Posted by robinson.s View Post
Hi guys,

Just for my understanding, If I change the low gear ratio or the dif ratio and increase the torque, will it be any better on such extreme muddy track. I really want to climb that stretch without winch.

Regards
Robinson
Technically (theoretically) to scale a slushy pit followed by an incline one needs Right amount of torque, Right momentum and Enough traction all 3 in "x" combination. In my words;
Right torque: to ensure the momentum is not lost within the first few yards just before hitting the slushy area, I mean the green patch before the epicenter of the slush itself. If you noticed you lost serious momentum just before hitting the trough each time. Now, if that wasnt happening may be your rear wheels wouldve had enough momentum just before the incline.

Right momentum: Right momentum will take the load off the tyres due to the inertia that is already generated and is acting in the intended direction. Hence a little loss of traction will be offset by the inertia already gained resulting in a head start just before the climb.

Enough traction: Tyres that will provide enough traction till the touch down to harder surface is experienced.

"x" = Unknown (subjective inputs provided by the driver specific to each 4x4 plus the inherent capability of the 4x4).

Taking your 4x4 into account here, my assumption would be that the bogging down just before the shush's epicenter if is taken care of you should be fine. That means greater momentum in the green patch. Simply, longer run up with may be 3rd gear Low ratio just before the slush dive.

Just my 2 cents. Experts throw light... Akra, Shahnawaz, Samurai, anyone???

p.s: Its only the theoretical aspect that I am highlighting here, so no one jumps on me with "there is a lot more to it than you think, something that you will learn after few more OTRs bla blah" LOL!!!

Last edited by The Wolf : 26th May 2010 at 12:34.
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Old 26th May 2010, 13:03   #62
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Default Diff-Ratio

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Originally Posted by robinson.s View Post
Just for my understanding, If I change the low gear ratio or the dif ratio and increase the torque, will it be any better on such extreme muddy track. I really want to climb that stretch without winch.
Hi Robinson,

For an Ideal Concrete Incline a Lower Differential Ratio will help.

On and Off-Road Lower Differential Ratio will improve torque through out the RPM Range; Acceleration will improve,But Max Speed will reduce.

So if you think momentum is the Key, then a lower (suitable) diff-ratio will help.

For 28" Tyres the following Diff-Ratios have been used.

1) B275 4.27:1
2) S4 4.27:1
3) MDI3200 4.27:1
4) MDI3200TC 3.73:1/4.27:1/4.88:1/5.38:1 (7.50X16)
5) XDP4.9 4.88:1/5.38:1
9) XD3P 4.88:1/5.38:1

Regards,

Arka
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Old 26th May 2010, 13:18   #63
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Originally Posted by The Wolf View Post
Just my 2 cents. Experts throw light... Akra, Shahnawaz, Samurai, anyone???
Oh boy, I am no expert. Besides, I don't comment on trails I haven't seen personally.

Quote:
Originally Posted by The Wolf View Post
Right torque: to ensure the momentum is not lost within the first few yards just before hitting the slushy area, I mean the green patch before the epicenter of the slush itself. If you noticed you lost serious momentum just before hitting the trough each time. Now, if that wasnt happening may be your rear wheels wouldve had enough momentum just before the incline.
How do you select the right torque?

Quote:
Originally Posted by The Wolf View Post
Taking your 4x4 into account here, my assumption would be that the bogging down just before the shush's epicenter if is taken care of you should be fine. That means greater momentum in the green patch. Simply, longer run up with may be 3rd gear Low ratio just before the slush dive.
I remember somebody mentioning about the danger of hitting the nose to the steering at the incline point. In that light, would you recommend long run up?
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Old 26th May 2010, 13:33   #64
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Default Sound Theory

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Originally Posted by The Wolf View Post
Technically (theoretically) to scale a slushy pit followed by an incline one needs Right amount of torque, Right momentum and Enough traction all 3 in "x" combination. In my words;
Right torque: to ensure the momentum is not lost within the first few yards just before hitting the slushy area, I mean the green patch before the epicenter of the slush itself. If you noticed you lost serious momentum just before hitting the trough each time. Now, if that wasnt happening may be your rear wheels wouldve had enough momentum just before the incline.

Right momentum: Right momentum will take the load off the tyres due to the inertia that is already generated and is acting in the intended direction. Hence a little loss of traction will be offset by the inertia already gained resulting in a head start just before the climb.

Enough traction: Tyres that will provide enough traction till the touch down to harder surface is experienced.

"x" = Unknown (subjective inputs provided by the driver specific to each 4x4 plus the inherent capability of the 4x4).

Taking your 4x4 into account here, my assumption would be that the bogging down just before the shush's epicenter if is taken care of you should be fine. That means greater momentum in the green patch. Simply, longer run up with may be 3rd gear Low ratio just before the slush dive.

Just my 2 cents. Experts throw light... Akra, Shahnawaz, Samurai, anyone???

p.s: Its only the theoretical aspect that I am highlighting here, so no one jumps on me with "there is a lot more to it than you think, something that you will learn after few more OTRs bla blah" LOL!!!
Hi Wolf,

So did you make the climb and what quantities of the above did you use in "x" combination, and same for the clay pit.

Regards,

Arka

PS - Theory if Fine, but is it sound
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Old 26th May 2010, 15:02   #65
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I remember somebody mentioning about the danger of hitting the nose to the steering at the incline point. In that light, would you recommend long run up?
Very honestly this is the first time i have tried this spot, so my observation might not be correct.

But the depth of the rut is the biggest problem (Its more than 2 feet)! The vehicle just brick walls like you hit a kerb! and then all the momentum/toque goes for a toss.

I was discussing with Shan on the way back, that maybe a moderate momentum to bounce off and climb will be more appropriate. Rather than what i performed on the day. Atleast thats what i should have done in my CJ3B.

No expert or guru here. Just mere mortals driving impressions

ps: Its actually forehead hitting wiper motor or windshield @ Samu's last line.

EDIT: Arka any idea what is stock for invader and one step increment should keep Robinson happy and i think he is travelling (to participate in an offshore OTR) so might respond in a while.

Last edited by Jaggu : 26th May 2010 at 15:05.
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Old 26th May 2010, 15:18   #66
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But the depth of the rut is the biggest problem (Its more than 2 feet)! The vehicle just brick walls like you hit a kerb! and then all the momentum/toque goes for a toss.
This just reminded me of something. Unless you have seat belts you should never attempt a run up in terrain where you have such deep ruts. You could smash your face into the front screen.

An acquantaince died in a similar incident when his Pajero hit such a rut on Chirala beach. He wasn't wearing seat belts. All the others in the car did and they were unhurt.

BTW who in India sells after market seat belts certified to international standards? I need to install a set for my Jeep! I want the racing harness type.
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Old 26th May 2010, 15:21   #67
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Originally Posted by Jaggu View Post
....
But the depth of the rut is the biggest problem (Its more than 2 feet)! The vehicle just brick walls like you hit a kerb! and then all the momentum/toque goes for a toss.
Yes, the slush pit becomes a ditch/rut and can cause serious damage if one tries to come in momentum. Here is what happens with a little bit of speed -- the radiator fan went for a toss here.

Pearl Valley May 23rd, Totally Unplanned OTR! (Report Update on Page 1).-p10.jpg

Pearl Valley May 23rd, Totally Unplanned OTR! (Report Update on Page 1).-p13.jpg

Some more innocent looking pictures of this place from earlier OTR's:

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Name:  DSC06186.JPG
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Pearl Valley May 23rd, Totally Unplanned OTR! (Report Update on Page 1).-100_4378.jpg

Pearl Valley May 23rd, Totally Unplanned OTR! (Report Update on Page 1).-dsc_5790.jpg
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Old 26th May 2010, 15:22   #68
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Guess what folks - A Good Samaritan has offered to give me a private lesson on handling my jeep on an OTR & we would be doing a small Reece :-) added to this he also offered to check my jeep for OTR readiness. How cook is that :-)
He has asked me to keep it under wraps but will surely report it once we are through - I profusely thank him in advance for all the help am going to get.
Me getting left out from this OTR turned out to be a blessing in disguise :-)
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Old 26th May 2010, 15:24   #69
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Thank god for once my head took over and I did not even try an attempt at this spot.
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Old 26th May 2010, 15:28   #70
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Hey DKG
Just follow the rally groups. They will be able to guide you better.
They typically use 5 point harnesses - but you will need to change your seats.
Alternatively you can get Sabelt and Momo 3point fixed seat belts in the market (sells for abt 5K pair) - you may need to search around for it.

Cheers
GB
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Old 26th May 2010, 15:30   #71
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Guess what folks - A Good Samaritan has offered to give me a private lesson on handling my jeep on an OTR & we would be doing a small Reece :-) added to this he also offered to check my jeep for OTR readiness. How cook is that :-)
Hey thats great!!

Just a word of caution: Hope you are aware of the samaritan's credentials and do take one more vehicle, some basic tools and recovery stuff if you are venturing out into good terrain. Most important ensure the vehicle tow hook's are working!


Quote:
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This just reminded me of something. Unless you have seat belts you should never attempt a run up in terrain where you have such deep ruts. You could smash your face into the front screen.
And some people never learn, this is the second time am having a lucky escape. First time it was idukki kerala. But yes i was quite unaware of the ruthless nature of this particular ditch. Makes you wonder if it has rocky formation or something there, there is something like that further towards the RT, i noticed this time.

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Alternatively you can get Sabelt and Momo 3point fixed seat belts in the market (sells for abt 5K pair) - you may need to search around for it.
DKG these should be perfect, unless you are putting a proper roll cage. Without which rally stuff are useless and can be quite dangerous also.

Last edited by Jaggu : 26th May 2010 at 15:34.
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Old 26th May 2010, 15:38   #72
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Khan ^^

How did the fan break? Did the entire grill assy shake and rub against the radiator? Or did some hard block of slush lodge itself onto the fan and shredding it?

Innocent pit - still not very conquerable!!
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Old 26th May 2010, 15:38   #73
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Thank god for once my head took over and I did not even try an attempt at this spot.
IIRC, you did not do anything in the second spot either. You just drove all the way to the OTR to be around with some great long lost friends of yours
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Old 26th May 2010, 15:49   #74
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... in the second spot either. ....
Khan, Jaggu - what was the name of the place (2nd spot)? Is it large and semi-private enough like the attibele lake bed? Is it good for 15 vehicles and half day of hanging around?

Please edit name to add the place's name too...
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Old 26th May 2010, 15:55   #75
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@jaggu - just saw the video of your climb , you had almost made it.
you would have made it if ur jeep had not veered to the left halfway up the incline.
In my opinion the best line to tackle this is to go for it STRAIGHT, stay in center. keep aiming for the aim for the big tree on top as direction change on the slippery incline is unpredictable. and start to turn left only after you have crossed 3/4 of the incline.

@wanky - you should have tried it .

a lot of people have done it at one go.

@shahnawaz - was the rut/ditch deeper this time?

@DKG - i think for jeeps the non inertia assisted 3 point seat belts should be enough. there used to a be a brand called "AUTOFRIEND" which used to be available, dont know if it is still. otherwise as suggested by gypsy boy - 4 point harness along with seat change is the only option.

Last edited by siddartha : 26th May 2010 at 16:00.
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