[Samurai]

Originally Posted by The Wolf

the best is the technique Jayesh suggested...but there is a subtle knack to it. Accelerate only when you feel that he vehicle is going sidewards.

Thanks Wolf, although I didn't understand the part going sidewards. Why accelerate when the vehicle is going sidewards, and should I be giving any steering inputs at the same time?

Originally Posted by The Wolf

If the vehicle is sliding slowly in straight line you can wait for a fraction to see if the vehicle will regain traction after traversing a couple of feet. If its completely evident that the traction cannot be regained and the vehicle is gaining too much momentum and will crash land into something in front, well, no choice again, squeeze the throttle till you believe is necessary and immediately pump &release the brakes at tandem quickly

squeeze the throttle if the vehicle is gaining too much momentum while sliding down the slope? I don't feel comfortable with that one.

Originally Posted by The Wolf

While doing the above ensure as much as possible turn into the slide holding the steering firmly...coz you dont want a piece of rock to flip-turn your steering in the wrong direction when most is already lost!!!

That did happen to me, I lost the steering for a moment and steering went totally to the right. What is the best option then?

[The Wolf]

Originally Posted by Samurai

Thanks Wolf, although I didn't understand the part going sidewards. Why accelerate when the vehicle is going sidewards, and should I be giving any steering inputs at the same time?

When you are rolling down a steep and slimy slope there is big chance the rear of your vehicle will step out. This is due to the momentum difference between the front and rear wheels. In low gears, the rpms the front wheels are rotating at is considerably lesser than the rear wheels. Though this is marginal its enough to get your rear wheels following a different track in comparison to the front hence the vehicle slides out. The other cause is ofcos the intertia difference between the front and the rear due to difference in traction levels. That is what I was trying to say in my previous post.

Originally Posted by Samurai

squeeze the throttle if the vehicle is gaining too much momentum while sliding down the slope? I don't feel comfortable with that one.

Yes, squeeze, not dump, squeezing can allow the tires to catch up with the momentum of the vehicle and quickly gain traction. Soon after which you will pump and release the brakes. I can understand that it wouldnt be easy for anyone of us to accelerate while going down hill but without that appraoch all is completely lost...........except the all mighty!

Originally Posted by Samurai

That did happen to me, I lost the steering for a moment and steering went totally to the right. What is the best option then?

Hence, hold the steering firmly, real firm while intuitively offsetting the unintended direction by turning gently into the direction of the jetting out rear. Heard of the term "counter steering"?? Thats what it is.

[Samurai]

Originally Posted by The Wolf

In low gears, the rpms the front wheels are rotating at is considerably lesser than the rear wheels. Though this is marginal its enough to get your rear wheels following a different track in comparison to the front hence the vehicle slides out. The other cause is ofcos the intertia difference between the front and the rear due to difference in traction levels.

Considering we are in 4WD mode why would front and rear axles turn in different speeds? I always thought the difference in traction between front and rear wheels is dissipated via slipping. Also, in firmer surface won't the different rpm in front and rear result in transmission windup?

Originally Posted by The Wolf

Yes, squeeze, not dump, squeezing can allow the tires to catch up with the momentum of the vehicle and quickly gain traction. Soon after which you will pump and release the brakes. I can understand that it wouldnt be easy for anyone of us to accelerate while going down hill but without that appraoch all is completely lost.

I think when Jayesh said accelerate, I thought he meant in situations where the jeep is slipping slowly in 1st low and not hurtling down with too much momentum. I guess Jayesh can clarify.

Originally Posted by The Wolf

Hence, hold the steering firmly, real firm while intuitively offsetting the unintended direction by turning gently into the direction of the jetting out rear. Heard of the term "counter steering"?? Thats what it is.

I have seen that done in the movie Cars. But I am not sure about the direction to use in counter steering. I was sliding to the right, front wheels turning to the right, so which way I should turn the steering gently to counter the turn? BTW, gently is not very easy to do when things go haywire in a hurry.

[Red Liner]

Dear All: As you know, seeing is believing. I would like to see all the advice given by Bangalore Jeepers in the OTR this Sunday. Kindly come prepared I will stand next to you and ask all questions as you tackle the terrain.

Sharath, please practice advice already given 25 times in that steep cliff behind your office before asking more questions

Jayesh, I hope you're not laughing at our discussions. I know you do this almost as a daily ritual. Driving offroad I mean. Okay, laughing at our discussions also

[The Wolf]

Originally Posted by Samurai

Considering we are in 4WD mode why would front and rear axles turn in different speeds? I always thought the difference in traction between front and rear wheels is dissipated via slipping. Also, in firmer surface won't the different rpm in front and rear result in transmission windup?

Think of the function of a differential lock, you will get your answer.

Originally Posted by Samurai

I think when Jayesh said accelerate, I thought he meant in situations where the jeep is slipping slowly in 1st low and not hurtling down with too much momentum. I guess Jayesh can clarify.

Thats his bit and this is mine. What do you think can be done anyway when the jeep is hurtling down, slam the brakes??!! The ONLY option is to out accelerate the skidding momentum and wait for traction just enough to steer in the intended direction. Remember, your jeep in 1st Low can never go HURTLING down on any slope which is thoughtfully chosen, moreover pressing the panic button can make you feel a lot more out of control than the reality =)

Originally Posted by Samurai

I have seen that done in the movie Cars. But I am not sure about the direction to use in counter steering. I was sliding to the right, front wheels turning to the right, so which way I should turn the steering gently to counter the turn? BTW, gently is not very easy to do when things go haywire in a hurry.

Sir, sit with me in my car sometime, I'l show you what you dont see in movies also . The fact is most of it is possible, we gotta have an open mind and a trying attitude. Writing off possibilities isnt something that will help.

We tuner car guys definitely have an advantage with reflexes Im guessing. We can make those split second decisions may be a wee bit better than the others... But ardent jeepers shouldnt have a problem Im guessing.

After all is said and done, in this open forum we are only discussing theoretical possibilities and assumptive dynamics of specific situations. Lets not mistake it for something that we can start following from tomorrow. Discussing and understanding right theories will lead into better mindset and advanced abilities in confronting challenging situations bit by bit, with each encounter. Until then its back to theories...

Originally Posted by Red Liner

Dear All: As you know, seeing is believing. I would like to see all the advice given by Bangalore Jeepers in the OTR this Sunday. Kindly come prepared I will stand next to you and ask all questions as you tackle the terrain.

First read my above statement.

Maga, go get your Jeep fixed first, before you stand next to me. Paid a tribute to it at Raju's garage today :P
BTW, how come you guys arent participating in TPC?

Originally Posted by Red Liner

Sharath, please practice advice already given 25 times in that steep cliff behind your office before asking more questions

LOLzzz

Originally Posted by Red Liner

Jayesh, I hope you're not laughing at our discussions. I know you do this almost as a daily ritual. Driving offroad I mean. Okay, laughing at our discussions also

We all laugh at each other for different reasons. Its a laughy world that we live in...some laugh and the others laugh for them!!!

[Red Liner]

Originally Posted by The Wolf

Maga, go get your Jeep fixed first, before you stand next to me. Paid a tribute to it at Raju's garage today :P
BTW, how come you guys arent participating in TPC?

Guruve, even if I dance like Shiva, the jeep will get done according to his speed only. I thought you would have figured this out by now considering your previous mechanic escapades.

Who said we're not participating?

[genesis]

Originally Posted by The Wolf

Hey Sharath, theoretically and from what I have learnt from several sources- the best is the technique Jayesh suggested...but there is a subtle knack to it.

@The Wolf:

As a newbie to offroading and given the various sources of information on this thread, (most of whom I know) am trying to get my head screwed around right in terms of perspective.

So a question for you:

Are you an experienced car guy (porting, polishing, remapping types) getting into offroading and these are your distilled viewpoints (from various sources and car experiences, a lot of which may be valid)

or are you an experienced offroader and these are your distilled experiences (a lot of which may be valid)

Right now with all these complicated discussions, I feel like a noob standing at the edge of a decline, with numerous left, left left, right right right being thrown at me

[sudev]

Sorry for nooobs observation here : The maximum retarding force that a tyre will take is the friction between it and the slope surface. No matter what the source of braking force is - engine+drive train or brakes - right?

To me, sitting away and never having done extreme off roading, the choice should be from the driver and spotter combo. And can depend on not only the current obstacle but also what come immediately after.

But a nice and educative thread none the less.

Any one tried ABS in down slope situations?

[Samurai]

Originally Posted by Red Liner

Dear All: As you know, seeing is believing. I would like to see all the advice given by Bangalore Jeepers in the OTR this Sunday. Kindly come prepared I will stand next to you and ask all questions as you tackle the terrain.

I am not giving any advice, just taking it. I will have lot of questions to you too.

Originally Posted by Red Liner

Sharath, please practice advice already given 25 times in that steep cliff behind your office before asking more questions

First I need to get my Jeep back, I'll surely practice after that.

Originally Posted by The Wolf

Think of the function of a differential lock, you will get your answer.

In case of center LSD, I can see your point. But Jeep/Gypsies don't have center diff, so that is as good as an all time full differential lock in the center. So transmission windup will be still the case. Or so I think.

Originally Posted by The Wolf

Thats his bit and this is mine. What do you think can be done anyway when the jeep is hurtling down, slam the brakes??!!

Yeah, yeah, I agree. Slamming brakes is no answer while sliding down in full momentum. While my offroading experience is limited, I do have tonnes of snow/ice driving experience of over a decade. Even there, touching braking is a cardinal sin. In fact, sliding in ice/snow always starts with a braking action.

Originally Posted by The Wolf

The ONLY option is to out accelerate the skidding momentum and wait for traction just enough to steer in the intended direction.

It is just scary, that's all.

[DHABHAR.BEHRAM]

Dear Sharath - to answer the question on how I tackled the slope on the first day, my reply is as follows:

First, I stopped the Thar away from the line of normal vehicles, got down and saw the slope. I waited till one CL340 and 1 gypsy passed (best and worst case scenarios). Then I climbed down the slope in my mind. My inference was that "this slope is not very steep" (it turned out that it actually wasn't), so for me at 4.3:1 (mid case scenario), the obvious choice would be 1st low. Then onwards, it was quite straightforward. As I had to control the vehicle and never the other way round, I started the apex of the slope with the brakes applied just enough not to stall the engine and also just enough not to allow the vehicle to go down on its own accord. Then onwards, manoeuvring both the pedals as and when required (I don't remember to have required much brake), I went down. After coming down, I was told that I appeared to have come down quite fast. However, the vehicle was in full control at all times.

Best regards,

Behram Dhabhar

[Samurai]

At 4.3:1 axle ratio, you had the perfect ratio to come down at 1st low without slipping or applying brakes. That is what I feel, others may feel otherwise.

Also, if you were in control, what others felt from outside doesn't count.

[robinson.s]

Originally Posted by DHABHAR.BEHRAM

Dear Robinson - I totally agree with you that we go offroading because it is our passion. But passion and machogiri are as different as chalk and cheese. Overcoming an obstacle using your vehicle's capability and your skill is passion. Trying to prove to all and sundry that you can do something which obviously cannot be done or is not safe to do is machogiri. Our hobby is such that a little bit of machogiri manages to creep in sometimes. I used to suffer from this syndrome in my early years but now I have disciplined myself not to indulge in it at all. That's why you may now remember that I was standing next to you when your vehicle was in the last waterlogged ditch before lunch on the first day but I did not take the Thar through it because I was mentally not comfortable with that damn ditch, so I just did not do it (I have absolutely hated water crossings all these years, well, I am like that only). If I were to succumb to pressure from others (oh come on yaar and all that), it would not be passion, it would be machogiri. Passion will reward you, machogiri will break your vehicle. If a person does not want to go, he should not go. Its his vehicle so its his decision, period. Everybody must understand and respect it. I think in our forum, everyone understands and respects, which is why all of us enjoyed ourselves.

Dear Sharath - if the Jeep is built with such a driveline ratio that you are apprehensive that it will slide down even in low 1st, the best option is to winch it down in reverse (because most Jeeps have the winch in the front). It is always better to have a winch at the back also. See the photograph attached, something I did some time back. Without a winch, I agree with Robinson's comment of going down inch by inch. If it still slides, PRAY!

May our tribe increase.

Best regards,

Behram Dhabhar

Dear Behram Sir - Thank you so much for your note. I guess most of us have long way to go to reach were you are now.
The only technique which i could remember, when I started off roading was to use only right foot. Floor the pedal to the maximum, dive or jump the obstacle, that's it! though it worked most of the time, but definitely it was the risky thing to do.

Really appreciate if we could discuss about the techniques on sand trails. The most common thing all of us know is;
Lighter vehicles with powerful engine
Softer suspensions
Deflated HT/AT tyres
And just drive with momentum with a appropriate angle.

how would you rate Tharon the sand terrain.

Looking for some good discussion around this.

Regards

[ex670c]

Hi Guys,

There are quite a few ways to go down a Slope.

i) With Gears; crawling down. 1St Low or Reverse Low.

ii) on Brakes; engine running, clutch depressed.

iii) Gears + Brakes with engine running. especially for vehicles with Higher Differential Ratio (3.73, 4,27, 4.3) or considerably heavier.

What to do if the vehicle slides?

i) As jayesh (JACK33)suggested, give a"BIT" of accelerator and give steering corrections in short jabs.

ii) Tap the Brakes, try not to do that while turning, it will aggravate sliding.

On some descents we all end up using the brakes, either to slow the vehicle down or console ourselves.Regards,

Arka

[jack33]

Originally Posted by Red Liner

Jayesh, I hope you're not laughing at our discussions. I know you do this almost as a daily ritual. Driving off road I mean. Okay, laughing at our discussions also

Hey Venky, this thread is making me think and analyze those maneuvers that comes automatically and convert those thoughts in to words and not LAUGHING.

Originally Posted by Samurai

I think when Jayesh said accelerate, I thought he meant in situations where the jeep is slipping slowly in 1st low and not hurtling down with too much momentum. I guess Jayesh can clarify.
.

Yeah Sarath I meant when slipping slowly and not hurtling down.And as Wolf rightly said most of the times when you are not in the beaten track/groove there is big tendecy that the rear moves and hence the steering inputs as Arka suggested.Even though we seldom slips that fast in 1st low, it happens sometimes (happened few times but not yet toppled/crashed) and i don't know any technique other than to be calm and pray.

Originally Posted by The Wolf

When you are rolling down a steep and slimy slope there is big chance the rear of your vehicle will step out.
.

Originally Posted by Red Liner

Jakku, you should see Jayesh climbing man...throttle variation + heel-toe to not slide back down...was totally loving it sitting next to him and watch the foot work. Messi all the way

.

Hey Venky, an apple a day makes you messi all the way.That night the jeep was freely slipping backwards in reverse.

@Jaggu, so you should plan another munnar OTR soon for practicing.
.

[DHABHAR.BEHRAM]

Dear all - Off Roading Technique On Sand? First let me tell you a short story.

The Great Escape, Rajasthan, 2002 - the month was February. It was damn cold in Mandawa in Rajasthan. This place is around a 100 odd kilometers out of Jaipur. We went there for the Great Escape (my first on sand). So, as usual, we took the morning Jet Airways flight out of Mumbai, enjoyed the excellent cheese omlette and started freezing the moment we stepped out of the aircraft. As is my ritual during these sorties, my trusted driver was waiting outside the airport with MH01P2540, my yellow "INVADER" prototype. It was actually a red 1994 model CJ340 with converted appearance and INVADER name (full credit to my driver who drove 1000 kms in a vehicle which with 5.38"1 axle ratio is a bloody pain to drive on tarmac). So, I took the vehicle from the driver, told him to hop into one of the Commander Hard Tops and we got going. Everything was "normal" (means we saw cars, bikes, buses etc) till we reached a small town called "Jhunjhunu". After Jhunjhunu, we barely saw anything except our M&M vehicles. CL550MDI4WD, CDR750DP4WD, CDRHT4WD. Everything was 4WD. We never saw a 2WD vehicle in Mandawa. We reached Mandawa and checked into a wonderful resort, appearing typical Rajasthani and rusty from the outside but with all modern amenities from inside. The time was around 1000 hrs, time to go for the recee.

Now my report starts - here I am only a messenger, conveying to you all what my "sand driving" teacher taught me that day. His name was Vir Singh or something like that. He was one of the local drivers who take the "firangs" on the sand dunes in Jeeps. The guy earns his living by driving on dunes everyday. He had a very staid looking cream coloured CL550MDI4WD with 6.00*16 M&S production tyres and he went through all dunes all over the place where all of us faltered. He was a very sober, quiet, typical Rajasthani guy with the long moustach, the glorious headgear and the quintessential "namaste" greeting. I requested him point blank to teach me the off roading technique in sand. "Show me", I said. So he showed it to us. The rule is "flotation and angle of attack".

"Flotation" - a lighter vehicle is a better vehicle. A faster vehicle is a better vehicle. The force per unit area that the tyre exerts on the ground must be bare munimum. Remove everything that is not required, he said. His vehicle did not even have a spare wheel.

"Angle of attack" - here, the basic difference between any other terrain and this terrain is that the road shifts continuously. The angle of attack on a dune is extremely important to ensure success. If you are climbing within a left turn, your right tyre will hit the dune first. Let the left tyre follow. Don't try to put both tyres up at the same time. You may need to hit a sand dune around 50 times (yes, 50 times) to "break its back" with your front bumper before you power your way up. Do it, that's the way. If you just can't climb, don't waste your time, just take a detour. The dune there will be equally exciting to climb. Sensible. Very sensible.

Tyre pressure - everyone knows that on sand you reduce tyre pressure. But to what level? He showed us that day. I was merrily running 30 psi (foolish of me, I knew but I wanted to see what would happen). A mere 100 meters off the tarmac, my vehicle got stuck. Then we started reducing the tyre pressure. He came and calmly stood next to us, watching us with a bemused expression on his face. Then he showed us the masterpiece of sand dune offroading. He took my right hand as if a father would guide a child, slowly rolled my fingers into a fist and told me to hit the tyre sidewall hard with the area next to my little finger. I hit hard and got hurt. He told me to keep on reducing the tyre pressure and keep on hitting with the same intensity till the hurt level reduces, means that the tyre will deform on hitting, means that the pressure is less. But till how long? You can't deflate completely. He knowingly nodded his head and told us "till you hear a "dhummm dhummm" sould from the tyre. We followed his advice and we were pleasently surprised to hear the noise change from "phut phut" to "dhumm dhumm". He also told us to look at the tyre / wheel rim interface. "You should see the tyre deflect very slightly off and then come back on the wheel rim again, at the point where you hit". So we did this to 4 tyres. It took us half an hour to complete this exercise. He told us that it would take half an hour. After the OTR, I measured the tyre pressure. It was between 13 / 15 psi. The vehicle misbehaved totally on tarmac so it was essential to restore the tyre pressure at a petrol pump but on sand it was pure nirvana. I then followed his vehicle all over the place. A couple of times he got stuck. He would calmly go forwards and backwards, "break the bacK" of the dune and continue as if nothing had happened.

He was such a simple, polite and unassuming soul. It was our delight to have met him and learnt from him. May his tribe increase. I salute him and his knowledge. Other drivers told us that he was known as the "master of the dunes" in Mandawa. All of us wished him all the best, we gave him a small memento consisting of a Great Escape tee shirt and a mantlepiece which thrilled him immensely. I have not met him after that trip but I can never forget what I learnt that day. Its here for all of you to know and share now.

After this incident, I went into Bikaner (2003), Manwar (2004) and Jaisalmer (2005) with the same CJ340 MH01P2540 and I have used these techniques to advantage.

Best regards,

Behram Dhabhar