[1100D]

Originally Posted by SS-Traveller

Does the Scorpio? 1100D?

Sorry Sir, was caught up! But, a very bad day (31-Mar) to have this going and looks like I missed being part of the fun here!

Originally Posted by SS-Traveller

Quick question to both of you veterans of Sandakphu:

Can you do the Sandakphu drive all the way without engaging 4L 1st and 2nd gears in your respective cars?

On the steepest sections, 4L 2nd was sufficient, although, I did not require to stop on the way up on any of the hairpins of the last 3kms.

However, digging out a rough calculation sheet (There will be "constants" relating to conversion factors that are to be disregarded for a quick evaluation) I had done before commenting on Himadri's thread in 2013, that the Duster AWD (Assuming that the specifications of the Indian car is same as the international one) will be able to do it.

Here goes (The whole calculation goes in the favour of Scorpio, till the final parameter, the weight).

[tsk1979]

Originally Posted by 1100D

However, digging out a rough calculation sheet (There will be "constants" relating to conversion factors that are to be disregarded for a quick evaluation)

I have a question. Shouldn't be the actual torque available be inversely proportional to the wheel ratio. I mean, the larger the wheel, the higher the effective gear ratio, as now car will go faster for the same RPM.

[DriveTrain]

What about the 21 Kms from Sandakphu to Phalut ? Point to point these are roughly at almost the same height but the track goes up and down. Some of the ruts in this section are absolutely atrocious. You have combinations of monstrous rut , flowing water , mid size boulders and slush on some of the slopes. Not sure how the under body would fare in such situations , particularly the exhaust and silencer of the Duster AWD. Was the Duster still shod in it's original MRF Wanderer Sport ?

I had the good fortune of being driven to Sandakphu and Pahlut last summer in a Land Rover , which had its original petrol engine intact and running ! For sheer driving pleasure and scenery this section is jaw dropping and gives you the opportunity to drive over pristine meadows and valleys. Our veteran driver opined that the ruts in the Sandalphu - Phalut stretch were more daunting that the steep climb to Sandakphu. He climbed from Bikeybhanjan to Sandakphu in dense fog , visibility was less than a few meters and our hearts were literally in our throats !

[Altocumulus]

I have personally been on this route. Its 31 kms from Manebhanjan to Sandakphu as per the milestones. 0 traffic (not a single car , only us 2 Bolero 4x4s) and the roads had melting snow. It took us about 8 hours that too with Blackpearl ahead of us leading and it was his 3rd trip there, and we following his track.There were a couple of hairpins which we could not turn in one go and one of us had to get off while reversing to make sure the vehicle does not fall of the cliff, simply because there is hardly a few centimetres to reverse and the turn itself was very very very steep.

To bring things into perspective, same trip, same cars, same drivers, from Kolkata to Siliguri via Bhagalpur I guess around 600 kms if not more it took us 12 hours, maybe a wee bit more .

[Samurai]

Originally Posted by tsk1979

I have a question. Shouldn't be the actual torque available be inversely proportional to the wheel ratio.

Yes, that is correct. Bigger the tyres, lesser the torque. Same reason why winch has more torque when the cable is fully out. 1100D has to change his calculations here, which only puts Duster at even more advantage against Scorpio.

http://www.4x4abc.com/4WD101/math_wheels.html

[BlackPearl]

Originally Posted by DriveTrain

What about the 21 Kms from Sandakphu to Phalut ? Point to point these are roughly at almost the same height but the track goes up and down. Some of the ruts in this section are absolutely atrocious. You have combinations of monstrous rut , flowing water , mid size boulders and slush on some of the slopes. Not sure how the under body would fare in such situations , particularly the exhaust and silencer of the Duster AWD. Was the Duster still shod in it's original MRF Wanderer Sport ?

I had the good fortune of being driven to Sandakphu and Pahlut last summer in a Land Rover , which had its original petrol engine intact and running ! For sheer driving pleasure and scenery this section is jaw dropping and gives you the opportunity to drive over pristine meadows and valleys. Our veteran driver opined that the ruts in the Sandalphu - Phalut stretch were more daunting that the steep climb to Sandakphu. He climbed from Bikeybhanjan to Sandakphu in dense fog , visibility was less than a few meters and our hearts were literally in our throats !

Yes some stretches of Phalut are tougher than Sandakphu, but the last incline to Sandakphu is the steepest. Here is a turn towards Phalut where ADC da who had traveled with me got down to take pics of the Bolero tackling the rock strewn road.

The travelogue link - http://www.team-bhp.com/forum/travel...-phalut-5.html

[1100D]

Originally Posted by tsk1979

I have a question. Shouldn't be the actual torque available be inversely proportional to the wheel ratio. I mean, the larger the wheel, the higher the effective gear ratio, as now car will go faster for the same RPM.

Originally Posted by Samurai

Yes, that is correct. Bigger the tyres, lesser the torque. Same reason why winch has more torque when the cable is fully out. 1100D has to change his calculations here, which only puts Duster at even more advantage against Scorpio.

http://www.4x4abc.com/4WD101/math_wheels.html

Both of you are right. Did not get time to recheck the calculations when posting. Have updated, however, can a Mod update the previous post with the appropriate one.

[SS-Traveller]

Originally Posted by 1100D

Here goes (The whole calculation goes in the favour of Scorpio, till the final parameter, the weight).

Interesting calculation, thanks. Small corrections:
- the Scorpio 4wd weighs 1920 kg, not 2080 kg.
- peak torque of 290 N-m in the mHawk engine is delivered at 1800 rpm (band 1800-2800 rpm); the Duster 110 delivers 248 N-m (not 245 N-m) at 1750 rpm (band unknown).

The results remain much the same, except when 1L (gear ratio 3.78) is deployed. Then the Scorpio obviously has a major advantage in climbing power.

If you could go all the way to the top in 2L only, without engaging 1L at all in your Scorpio, the Duster AWD ought to theoretically do it quite easily.

Sustained gradeability figures for the Scorpio S10 4wd: 30 degrees.
Sustained gradeability figures for the Safari 4wd: 26 degrees.
(Very interesting) Sustained gradeability figures for the Unimog: 49.5 degrees.
Sustained gradeability figures for the Duster AWD: Unknown.

Time to find out the abilities of the Duster AWD in reality!

[1100D]

Originally Posted by SS-Traveller

Interesting calculation, thanks. Small corrections:
- the Scorpio 4wd weighs 1920 kg, not 2080 kg.

Bingo! That actually (partially) explains another phenomenon! With the Yeti!!

(I took the 2080 figure from the R/C Card of Marengo)

[ManuMacher]

Nice thread. I would suggest that this be expanded to include which vehicle in India would be most appropriate to do this terrain. Driving Skill and ones mettle does play an important role. Request Sandakphu experts to comment whether Gypsy, MM540/550, Willy's are better compared to even Bolero's, Scorpio's, Safari's, AWD Duster's. I am assuming the better Specs of Willy's or the light weighted Gypsy will find it lot easier.

[SS-Traveller]

Originally Posted by 1100D

Bingo! That actually (partially) explains another phenomenon! With the Yeti!!

(I took the 2080 figure from the R/C Card of Marengo)

What phenomenon? The car or Bigfoot?

The weight data for Scorpio are from the owners' manual as well as the workshop manual.

[arjab]

Originally Posted by ManuMacher

...whether Gypsy, MM540/550, Willy's are better compared to even Bolero's, Scorpio's, Safari's, AWD Duster's. I am assuming the better Specs of Willy's or the light weighted Gypsy will find it lot easier.

Ages back, 1997 to be exact, we had attempted Sandakphu in a 1st gen soft top Gypsy, the 970cc, carb fed, narrow track variant.
It could not make it as the front free-wheeling hubs failed in the last leg. I think the hubs in those Gypsy's were Aisin's? (where you had to get out of the vehicle and manually lock/unlock them). Anyways, i remember, there was a almighty "K-r-r-r-r-r-r" noise from the front-left hub and no matter what we did it just did not unlock. We abandoned the idea of continuing further.

Also another problem which we had faced was with wheel articulation in the hairpins. The Gypsy's leaf springs just did not let the inside, unloaded wheels, when taking hairpins, "hang" low enough to kiss terra firma, resulting in precious power being wasted by spinning it away! Also on the loose rocks and ruts, the stiff leaf springs did result in a certain amount of "wheel-hop".

The GC, light build and the narrow track actually was favourable for the trail.

I cant tell you about the newer, fuel injected and more powerful Gypsy King's performance in the same terrain as i have had no experience with it. But you may take a look at the wheel articulation aspect. With grippy tyres the Gypsy may just make it.

[1100D]

Originally Posted by SS-Traveller

What phenomenon? The car or Bigfoot?

The car for sure.

This part of the calculation regarding the Yeti (with Scorpio's weight taken as 2080 as against 1920), was actually suggesting quite the opposite to an observation regarding the Yeti's performance on the same route, that too between Gairibash and Kaiyakatta (Gairibash is about 11 kms from S'phu)



Another interesting observation was, though the Scorpio has the same GC as the Yeti at 180mm, there has been no bottom-scraping on the Scorp.

The Yeti turned back.

[BlackPearl]

Originally Posted by shuvc

Back to the topic.
Totally rookie question I guess, but what tyres would be ideal on that terrain?

I had Maxxis 751 tyres all the three times that I went there. As far as I know 1100D has used different tyres during his trips at different times. The sidewalls need to be strong as there are jutting stones at places.

[nilanjanray]

Oh well. I had been planning to do a Sandakphu drive in my Fortuner. I had hiked there during my college days, even then Land Rovers used to do regular duty.

If the trail is so narrow, and there is limited space to reverse when tackling a hairpin bend (assuming the angle is too acute for one to do it in one go), then a longish vehicle with a large turning radius would be at a disadvantage.

So not advisable for 4x4 Fortuner/Pajero Sport/Endeavour/Safari? The boulders or gradient shouldn't be a problem with a good AT tyre, a narrow switchback without space to reverse (3 point turn) would be.