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Old 22nd October 2014, 19:30   #31
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Default Re: Thar CRDe: Improving its low-end torque

Quote:
Originally Posted by Sutripta View Post
As an experiment, one could fit smaller wheels mimicing the required final drive ratio to see if it helps.
Quote:
Originally Posted by tsk1979 View Post
The only thing you can do at lower cost is go for 15" tires. You wil lose around 20mm of GC, and gain about 10% extra torque.
Quote:
Originally Posted by DirtyDan View Post
I follow Sutripta's logic of using smaller wheels.
The smaller wheels are suggested as an (easy) experiment to find out if a slight reduction in gearing will help or not, not as a permanent cure. If found suitable, changes should then be made to the gearing.

Another easy (illegal) suggestion: Block off the EGR. Depending on ECU programming, might or might not help.

Quote:
Originally Posted by AVR View Post
OT: Your suggestion if possible in the KMT-90 would be great for the 4th gear (from1:1 to 0.75:1) but it's off-topic here. Would love to know though if its possible.
On bikes, play around with the sprockets. Be very sure of what you want, because what you might gain on one hand, you loose (something else) on the other.
Regarding internal GB changes, would suggest you not even think of it.
(Plenty of passionate vocal engineers/ physicists on that thread. Am sure they can better guide you. )

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Sutripta
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Old 22nd October 2014, 20:27   #32
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Default Re: Thar CRDe: Improving its low-end torque

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Originally Posted by AVR View Post
Not sure if someone mentioned earlier but the DieselTronics box for Thar has a special "off-road" tune which provides better lower-end, or so they claim. Would recommend looking it up.
Link
The "crawler" button on the box flattens out the torque curve to prevent turbo surge. On highways the Thar feels lethargic on this mode but you get pretty good fuel efficiency. My Thar averaged about 13.5km/l on this mode.

The other modes P1 and P2 offer quite a boost however my temperature gauge started acting strangely on P2 mode{rapid overshoots and declines }I wouldn't recommend long term use of the P2 mode. Fuel efficiency did not drop on P1 mode though.

Drop in Tyre pressure had quite a negative effect on torque and top speed however the ride quality improved tremendously!

Regarding low end torque well after driving a Duster 110PS and a Thar on separate Ladakh trips the Thar beats the Duster fair and square. Had to burn the clutch several times on the Duster.
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Old 23rd October 2014, 18:19   #33
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Default Re: Thar CRDe: Improving its low-end torque

Just saw I posted something about bikes here! Wires crossed. Apologies.

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Sutripta
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Old 26th October 2014, 15:12   #34
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Default Re: Thar CRDe: Improving its low-end torque

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Originally Posted by DirtyDan View Post

My Invader's MDI3200tc with 4:88 crown gears waltzes up these steep slopes without breaking a sweat in 2nd gear with power to spare. My Thar too often requires 1st gear and a fervent prayer.
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Originally Posted by alpha1 View Post
I believe this EXACTLY is the basic difference between the DI Thar engine and the CRDE Thar engine. The DI engine has good torque available even at idling.


247 Nm @1800-2000 RPM for CRDe (quite high up in revs)
182.5 Nm @ 1500 - 1800 rpm for TDI engine (at lower revs, and my extrapolation is value higher than crd at near idling)
(btw have a look at TATA Sumo engine: 250Nm @ 1000 - 2000 rpm!!!)
Quote:
Originally Posted by Rohit Tripathi View Post
Hi Dan,

Did you consider Thar DI before buying the CRDE and if yes what made you choose CRDE?

I know my question does not help you but it will be good to know your point of view.

Regards
Rohit
I have a Thar DI. I live at Chandigarh and the hills are just 30 k.m. from my home. I travel to the hills once a week. I have driven a Thar Crde a couple of times to the hills. I extensively use my Thar DI for hill travel. The DI is an absolute delight in the hills. Not much gear changing required, just a gentle tap of the foot and it climbs with abandon. The Crde on the other hand is 'dead' under 2k rpm. Two things that have helped me further with climbing hills on my Thar DI are EGR blanking and Cat Con byepass. I wonder if these two mods can be done on the computer controlled Thar Crde! Why do jeeps have computers?!? I read somewhere that a computer kills the 'crawling nature' of the jeep. This line helped me pick up the Thar DI!
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Old 26th October 2014, 18:05   #35
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Default Re: Thar CRDe: Improving its low-end torque

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Originally Posted by jassi_jeeper View Post
I have a Thar DI. I live at Chandigarh and the hills are just 30 k.m. from my home. I travel to the hills once a week. I have driven a Thar Crde a couple of times to the hills. I extensively use my Thar DI for hill travel. The DI is an absolute delight in the hills. Not much gear changing required, just a gentle tap of the foot and it climbs with abandon. The Crde on the other hand is 'dead' under 2k rpm. Two things that have helped me further with climbing hills on my Thar DI are EGR blanking and Cat Con byepass. I wonder if these two mods can be done on the computer controlled Thar Crde! Why do jeeps have computers?!? I read somewhere that a computer kills the 'crawling nature' of the jeep. This line helped me pick up the Thar DI!
Yeah, good questions on the EGR and bypass. Dunno, worth finding out for sure.

Part of the problem maybe either the CMRV or the BSIV requirements that probably fixed fuel economy without taking into consideration, hills. People in the Punjab love the Thar CRDe. It's flat there. The other part of the problem is an unimaginitive and monolithically stupid bunch who work at, THAT PLACE, from which nothing right is wrought. Not that I am bitter, mind you

Last edited by Samurai : 26th October 2014 at 21:56. Reason: mind the language
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Old 1st November 2014, 19:20   #36
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Default Re: Thar CRDe: Improving its low-end torque

There is a pro side and adverse side to everything.

Increasing tyre pressure to 32 psi may have a positive side to torque but tyre contact area will reduce leading to poorer brakeing. The vehicle becomes more bouncy that too on unpaved, hill area graded tracks.
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Old 5th November 2014, 15:58   #37
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Default Re: Thar CRDe: Improving its low-end torque

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GTO, too much chance of snapping the rear axle by using LOW range in this way. I am not sure how much is too much in this case and I don't really want to find out.
Have driven my Jeep in 2nd low + 2WD several times in the last 17 years / 2+ lakh kms. Rear axles only changed once at about the 1.7 lakh kms mark (don't remember exact odo reading, but it was after 1.5 lakhs).

How come my rear axles never complained? I've faced several situations where I didn't need to lock my front hubs, yet required the additional torque from low.

Samurai had this to add (from another discussion): So what happens if front wheels lose traction while climbing a hill, the rear axles are not designed for that scenario?
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Old 5th November 2014, 17:07   #38
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Default Re: Thar CRDe: Improving its low-end torque

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Originally Posted by GTO View Post
Samurai had this to add (from another discussion): So what happens if front wheels lose traction while climbing a hill, the rear axles are not designed for that scenario?
Not just me, Dhanush had asked this question two years back.

Quote:
Originally Posted by dhanushs View Post
Going by this logic, even if FWH is locked, if, any one of the front wheels are spinning freely.. Meaning, when front diff is open, the rear axle can break if load is high and both rear wheels have traction?
Sutripta replied here: http://www.team-bhp.com/forum/4x4-te...ml#post2994995 (Using 4L for Engine Braking/Torque with FWH Disengaged).

And Behram agreed with it, adding that car makers usually don't recommend such operations. But then we know car makers don't even recommend tyre upgrades.
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Old 5th November 2014, 19:25   #39
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Default Re: Thar CRDe: Improving its low-end torque

This is not a risk I routinely want to take even around Dharamsala H.P. where it's a 4 hour jaunt by recovery vehicle to Pathankot and a capable Mahindra dealer. I would not want to try this 2wd low range technique up in Ladakh. It might take a month for a repair, or worse.
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Old 6th November 2014, 14:54   #40
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Default Re: Thar CRDe: Improving its low-end torque

DD, the Thar rear axles are pretty solid. In our place, these same axles in different vehicles are put to solid abuse, and are well known for their durability.

So, I guess in a Thar, with just a passenger payload, and sensible usage of clutch, you can safely use the low range for more torque/extra gear.
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Old 6th November 2014, 19:20   #41
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Default Re: Thar CRDe: Improving its low-end torque

Dan yesterday I put in a Dieseltronic box. It has improved drivability and throttle response.
2nd gear now performs as it should originally have done 7 out of 10 occasions. When the tarmac is broken and you slow down a lot on an upslope you still have to shift to1st.
However I dont know what it is doing to the durability of the engine. I use only P1.
Overall about 6 out of 10.
I guess there is only so much you can do with a piggyback box.
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Old 7th November 2014, 19:52   #42
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Default Re: Thar CRDe: Improving its low-end torque

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Dan yesterday I put in a Dieseltronic box. It has improved drivability and throttle response.

2nd gear now performs as it should originally have done 7 out of 10 occasions.
However I dont know what it is doing to the durability of the engine.

I guess there is only so much you can do with a piggyback box.
The main risk when changing the fuel/air ratio via an aftermarket box is raising the temperature of the exhaust gasses and hence the aluminum turbo as well which is prone to warping and melting. If the box creators do it responsibly then it's not a problem. Aftermarket boxes are routine fare in North America and most have good reputations. Banks Inc. is one of the big names there. They also sell tuned exhaust systems, air intact products and instruments to measure boost, engine temp, exhaust temp etc. And, yeah, this stuff is expensive.

If I were going to go this route then I would also probably opt for a good synthetic motor oil to mitigate the risk.

http://www.bankspower.com/tuner

Last edited by DirtyDan : 7th November 2014 at 20:11.
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Old 7th November 2014, 20:43   #43
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Default Re: Thar CRDe: Improving its low-end torque

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Originally Posted by DirtyDan View Post
The main risk when changing the fuel/air ratio via an aftermarket box is raising the temperature of the exhaust gasses
At idle/ low engine speeds? (which is what I think your requirement was.)
AFR?

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Old 7th November 2014, 20:51   #44
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Default Re: Thar CRDe: Improving its low-end torque

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Originally Posted by Sutripta View Post
At idle/ low engine speeds? (which is what I think your requirement was.)
AFR?

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Sutripta
No, good sir. At heavy engine load accelerating from a stop and, particularly for me, going, proceeding up steep hills, having to slow down often due to switchbacks, curves, on-coming traffic. This is low vehicle speed but heavy engine load.
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Old 7th November 2014, 20:55   #45
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Default Re: Thar CRDe: Improving its low-end torque

Normally, when does a turbo glow red hot?

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