avg crawl ratio ?

[TreeClimber]

And for those who don't have a clue,
you take the lowest gear of the transmission (say 6.32 for a T18)
and multiply it by the lowest gear of the transfer case (say 4.0 to 1)
and multiply it by any secondary reduction box, if you got one (say 2.72)
and multiply it by the final axle ratio (say 4.56)
and total that up, and that's your mathamatical crawl ratio.

For those of you with Automatic transmissions, if your crawl ratio makes you feel inferior, you can also multiply it by the 'theroetical' multiplication due to the torque convertor. Some say it more than doubles the pull (X 2.5), others say it gives less (X 1.8)

 

[TreeClimber]

C4-5:46:1 diffs- 5:38. Atles 10:3:1. =365:1

What?

I thought C4 had 2.46 low gear. How the F, do they drop it from 2.46 to 5.46? That's a huge gear change.

edit... and even if you multiply 5.46 X 5.38 X 10.3 it equals 302:1..... are you factoring in another 63:1 just for the torque convertor?

 

[TreeClimber]

More useless posts from TreeClimber

Efficiency and torque multiplication
A torque converter cannot achieve 100 percent coupling efficiency. The classic three element torque converter has an efficiency curve that resembles an inverted "U": zero efficiency at stall, generally increasing efficiency during the acceleration phase and low efficiency in the coupling phase. The loss of efficiency as the converter enters the coupling phase is a result of the turbulence and fluid flow interference generated by the stator, and as previously mentioned, is commonly overcome by mounting the stator on a one-way clutch.
Even with the benefit of the one-way stator clutch, a converter cannot achieve the same level of efficiency in the coupling phase as an equivalently sized fluid coupling. Some loss is due to the presence of the stator (even though rotating as part of the assembly), as it always generates some power-absorbing turbulence. Most of the loss, however, is caused by the curved and angled turbine blades, which do not absorb kinetic energy from the fluid mass as well as radially straight blades. Since the turbine blade geometry is a crucial factor in the converter's ability to multiply torque, trade-offs between torque multiplication and coupling efficiency are inevitable. In automotive applications, where steady improvements in fuel economy have been mandated by market forces and government edict, the nearly universal use of a lock-up clutch has helped to eliminate the converter from the efficiency equation during cruising operation.
The maximum amount of torque multiplication produced by a converter is highly dependent on the size and geometry of the turbine and stator blades, and is generated only when the converter is at or near the stall phase of operation. Typical stall torque multiplication ratios range from 1.8:1 to 2.5:1 for most automotive applications (although multi-element designs as used in the Chevrolet Turboglide could produce more). Specialized converters designed for industrial or heavy marine power transmission systems are capable of as much as 5.0:1 multiplication. Generally speaking, there is a trade-off between maximum torque multiplication and efficiency

 

[Eric]

108:1

toy stuffs

 

[crazybluerider1]

This is a good link to have in this thread.

http://www.grimmjeeper.com/gears.html

I'm 172:1

 

[monstaru]

Crawl ratio is as irrelevant as an RTI ramp score.

On certain low power vehicles (Toyota/Suzuki) there is a universally agreed "magic number" but aside from those kind of rigs, crawl ratio is just a pointless statistic.

look, not all of us can have too much power coming out of our asses, and the tires to match.
i have one of those "low power" vehicles.hence why i asked.
granted, how effective it is depends on your power and tire size, but relevant none the less....

the calc on the first page is pretty spot on Crash....cheers, brian

 

[bigdog165511]

What?

I thought C4 had 2.46 low gear. How the F, do they drop it from 2.46 to 5.46? That's a huge gear change.

edit... and even if you multiply 5.46 X 5.38 X 10.3 it equals 302:1..... are you factoring in another 63:1 just for the torque convertor?

I don't rember what calculator I used
thairs a 6 pi

 

[mudmaster]

I'm at about 98:1

 

[TreeClimber]

thairs a 6 pi

 

[boxboy]

AX 15 3.83
atlas 4.2
D60 5.13

82.5

 

[Jaydog]

TJ, 5 speed, 4:56 gears, 37" tires, I'm around 79:1 which is not bad for what I wheel, but it is a little high when I get into the rocks or tight spots.

Crawl ratio is as irrelevant as an RTI ramp score.

On certain low power vehicles (Toyota/Suzuki) there is a universally agreed "magic number" but aside from those kind of rigs, crawl ratio is just a pointless statistic.

I totally disagree, it matters less on an automatic, but if you are running 3.20 gears and 38" tires while trying to finesse your way over a rock pile in a 5 speed, then your clutch would completely disagree with your statement.

 

[Fordzuki]

M50d 3.72
sami case 6.5
stock r&p 3.73
final 90.1914

Imo, the one time you need to know your crawl ratio is trying to match it to winch speed.

 

[SJR]

Looks like 90 for me , you will see in July :haha::corn:

 

[Glenn]

Curious what one uses a 300:1 ratio for? I think Marlin's site says around 230:1 is "ideal."

 

[Jaydog]

Curious what one uses a 300:1 ratio for? I think Marlin's site says around 230:1 is "ideal."

I don't know, I do know that Gibby has a few gears that are slower than molassus in winter time, you can run it at 4000 rpm and not catch a slug :redneck:

 

[Damnyankee]

I have 211:1 and i have used it exactly 3 times.

only on really steep, offcamber lifts, where i don't want to have to touch the clutch and get it tippy.

 

[JOOP]

Curious what one uses a 300:1 ratio for? I think Marlin's site says around 230:1 is "ideal."

I'd be happy with 100:1 :booo:

 

[Money Mark]

i have one of those "low power" vehicles.hence why i asked.

I do too.:; That's how I know.:;:;

 

[Money Mark]

.....while trying to finesse your way over a rock pile in a 5 speed, then your clutch would completely disagree with your statement.

My favorite position in my dual cased Toyota is 1 case in (4.7) and second gear.......yes, even on the rocks. My clutch is fine.:hi:



This is just another example of driving skill......or lack.

 

[Eric]

My favorite position in my dual cased Toyota is 1 case in (4.7) and second gear.......yes, even on the rocks. My clutch is fine.:hi:



This is just another example of driving skill......or lack.

That is usally where I am running trails too. But I dont have the 4.7 option yet. But both stock cases in 2nd gear is a nice gear to keep up with most groups or at least they may get ahead but you catch them on the hard stuff.