RCCrawler Forums

RCMFMaxxMan · 10-24-2005, 04:28 PM

I searched and found nothing. I was just wondering if torsion diffs would be better than just plain locked. Because you'd get better turning and the power to the tires with traction...so why do i never hear of anyone using them??? (this is for a mad force by the way so dont say because no one makes them for the trucks because there are some for the mad force.)

chafey · 10-24-2005, 05:33 PM

i thought they were torsen,diffs .probably the price.and under the right conditions they can unload.plus do you know how long that would take to break in on a crawler!

JakeTheAlligatorMan · 10-24-2005, 05:38 PM

Quote:

Originally Posted by RCMFMaxxMan

I searched and found nothing. I was just wondering if torsion diffs would be better than just plain locked. Because you'd get better turning and the power to the tires with traction...so why do i never hear of anyone using them??? (this is for a mad force by the way so dont say because no one makes them for the trucks because there are some for the mad force.)

What are you talking about? got a link? Pic?

Highmark · 10-24-2005, 05:54 PM

They use them in 1/8 scale buggys. If I remeber correctly they send power to the wheel that has more traction insted of unloading like a normal diff. So really, they work the exact oppesit of a normal diff.

Or at least I think that's how they work-feel free to correct me.

I don't see how it would help really, and I think it would be alot harder on parts. For example, say one wheel gets stuck in a bind, that wheel would recieve the power while the wheel that was free to spin would just....set there. As apposed to a locked diff which would send power to both wheels.

Grizzly4x4 · 10-24-2005, 06:01 PM

They are cool.
http://www.duratrax.com/pdf/dtxc9733-9734-manual.pdf

but like in the 1:1 world a locked diff wins for crawling and besides that there are limited trucks you can uses them in.

moonbuggy · 10-24-2005, 07:02 PM

a torsen diff is the same as a posi and a limited slip, they either have clutches or worm gears so if there is little pressure on a tire it will almost lock up, but with crawling there are always enormous pressures on the tires so it would never lock and never help out.

RCMFMaxxMan · 10-24-2005, 10:29 PM

yeah sorry i meant torsen. I understand i think...that they only go into effect with low amounts of pressure. is this correct?

JasonInAugusta · 10-25-2005, 12:18 AM

Torsens (TORque SENsing) diffs work like an open diff when equal amounts of torque are going to both halves of the diff. (or to both wheels)

What causes the Torsen to engage is a difference in torque between the two halves of the diff.

What determines the point at which the torsen engages is the actual design of the diff gears.

*EDIT*

Did a quick search...here's some good reading on Torsens.

http://www.sonic.net/garyg/zonc/Tech...ferential.html

moonbuggy · 10-25-2005, 12:26 PM

Quote:

Originally Posted by JasonInAugusta's link to torsen diffs

"The maximum amount of torque conveyed by the drive axles collectively is limited to approximately twice the amount of torque supported by the drive wheel having the least traction."

http://www.sonic.net/garyg/zonc/Tech...ferential.html

so that means that if a wheel is in the air, it will have zero traction and 2 times 0 is 0 so your truck isn't going anywhere

I'll just stick to spools and lincoln lockers

RCMFMaxxMan · 10-25-2005, 04:22 PM

wait doesn't it just send the power to the tire with MORE traction (the only one that really needs it)?

monsterjeepn · 10-25-2005, 05:13 PM

kk u guys i got it... at least i think i do... i know this is at least a diff that is similar to a torsen but not sure if im gettin somethin mixed up

. a torsen diff forces both axles to turn at the same time, however they may turn at different rates as long as BOTH are turning... i.e: if one stops the other has to, but they will act as an open diff with respect to turning and such. basically what the torsen does is let the axle shafts turn in opposite directions with respect to each other (through a series of opposing worm gears), but since the whole unit is turning in one direction, it appears that they are just turning at different rates. hope this clears some of the confusion up...

oh and of course corrections are welcome... as long as they are CORRECT

JasonInAugusta · 10-25-2005, 07:33 PM

Quote:

Originally Posted by moonbuggy

so that means that if a wheel is in the air, it will have zero traction and 2 times 0 is 0 so your truck isn't going anywhere

I'll just stick to spools and lincoln lockers

That's how an open diff works.

2.2 Comparison with open differential

The just-mentioned characteristic of the Torsen differential may be best appreciated in comparison with the inherent torque transfer characteristics of an 'open' or conventional differential. The drive axles associated with an open differential are interconnected by a bevel gear set designed to divide equal torque between drive axles. This arrangement will not support any substantial torque difference between the drive axles and, as a consequence, offers very little resistance to differentiation. Virtually any attempt to deliver an increased amount of torque to one of the drive axles will result in rotation of the gear set as evidenced by differential rotation between drive axles. For example, if one of the drive wheels should lose traction, any attempt to deliver additional torque to the other drive wheel having better traction will result in undesirable 'spin up' of the wheel having poorer traction. The maximum amount of torque conveyed by the drive axles collectively is limited to approximately twice the amount of torque supported by the drive wheel having the least traction.

EeePee · 10-25-2005, 07:45 PM

Tire in the air, Torsen doesn't work at all.

monsterjeepn · 10-25-2005, 09:31 PM

Quote:

Originally Posted by EeePee

Tire in the air, Torsen doesn't work at all.

thats not true... ummm hmmm if i knew how to put pics up i would but there is a lego model of a torsen that explains it very well... worm gear torsens will work if one or both of the tires is in the air... worm gears only work one way right? (worm can drive gear but not vise versa) so that means that the torsen has to have both wheels turning at the same time... here's the link to the lego model:

http://www.brickshelf.com/cgi-bin/gallery.cgi?i=69361

go there and keep in mind that a worm gear set up will only drive one way...

EeePee · 10-26-2005, 04:33 AM

Quaife differentials are Torsen types, they don't work with one tire in the air.

That was my point of reference.

(Been racing real cars for 8 years)

crawlerkid · 10-26-2005, 05:05 AM

You can LSD (limited slip diff) diffs using o-rings but it doesnt last very long, especially in the bigger rigs.

moonbuggy · 10-26-2005, 10:40 AM

so some of you say it acts like a automatic locker and others say the same thing except it won't work when one tire is off terra firma, we both can't be right. I think I'll go ask Jeeves

moonbuggy · 10-26-2005, 10:46 AM

okay all of the ask jeeves links said same thing, won't work when a tire is off the ground.

EDIT: P.S. look at the graph of performance vs. traction in Jason's link and you will see when traction equals zero (all the way to the left) efficiency drops to zero as well. Meaning it won't work!!

Grizzly4x4 · 10-26-2005, 12:40 PM

First of all. If torsens were superior to lockers and spools we all be using them on our 1:1 trail rigs and there would be no need for air/electric lockers.

I can see where a worm gear diff might lock everything up but who makes one?

A torsen diff (helical cut gear type) will, at some point, send all the power to the tire with no traction.

Does this mean that nobody should try the torsen diff for the Mad Force axles? Heck no, I would love to see someone try it.

Micropuller · 10-26-2005, 01:37 PM

A torsen diff has a gear ratio. If the ratio is 4:1, this means that the diff will send up to 4 times the torque to the wheel with the most grip. If the tires have equal grip, the torque will be divided 50/50. If one wheel is in the air, the diff will send 4 times the torque to the other wheel and 4 x 0 = 0

Humvee's are als equipped with torsen diffs. During training, the students are tought to put their foot on the brake when the vehicle lifts a wheel.

10-24-2005, 04:28 PM	#1
RCMFMaxxMan RCC Addict Join Date: Jun 2004 Location: ORegon Posts: 1,002	Torsion diffs vs. locked diffs I searched and found nothing. I was just wondering if torsion diffs would be better than just plain locked. Because you'd get better turning and the power to the tires with traction...so why do i never hear of anyone using them??? (this is for a mad force by the way so dont say because no one makes them for the trucks because there are some for the mad force.)

10-25-2005, 12:18 AM	#8
JasonInAugusta 06 Super National Champ Join Date: Jun 2004 Location: Stark Industries Bar and Grill Posts: 11,361	Torsens (TORque SENsing) diffs work like an open diff when equal amounts of torque are going to both halves of the diff. (or to both wheels) What causes the Torsen to engage is a difference in torque between the two halves of the diff. What determines the point at which the torsen engages is the actual design of the diff gears. EDIT Did a quick search...here's some good reading on Torsens. http://www.sonic.net/garyg/zonc/Tech...ferential.html Last edited by JasonInAugusta; 10-25-2005 at 12:21 AM.

10-26-2005, 05:05 AM	#16
crawlerkid Rock Stacker Join Date: Oct 2005 Location: Newbie general!!! Posts: 89	Lsd You can LSD (limited slip diff) diffs using o-rings but it doesnt last very long, especially in the bigger rigs.

10-24-2005, 05:33 PM	#2
chafey Rock Crawler Join Date: Aug 2004 Location: woods cross utah Posts: 523	i thought they were torsen,diffs .probably the price.and under the right conditions they can unload.plus do you know how long that would take to break in on a crawler!

10-24-2005, 05:54 PM	#4
Highmark I wanna be Dave Join Date: Jan 2004 Location: Austin Texas Posts: 3,866	They use them in 1/8 scale buggys. If I remeber correctly they send power to the wheel that has more traction insted of unloading like a normal diff. So really, they work the exact oppesit of a normal diff. Or at least I think that's how they work-feel free to correct me. I don't see how it would help really, and I think it would be alot harder on parts. For example, say one wheel gets stuck in a bind, that wheel would recieve the power while the wheel that was free to spin would just....set there. As apposed to a locked diff which would send power to both wheels.

10-24-2005, 06:01 PM	#5
Grizzly4x4 PapaGriz Yo Join Date: Apr 2004 Location: In the garage building the wife a crawler Posts: 13,137	They are cool. http://www.duratrax.com/pdf/dtxc9733-9734-manual.pdf but like in the 1:1 world a locked diff wins for crawling and besides that there are limited trucks you can uses them in.

10-24-2005, 07:02 PM	#6
moonbuggy Quarry Creeper Join Date: Jun 2004 Location: Ventura Posts: 326	a torsen diff is the same as a posi and a limited slip, they either have clutches or worm gears so if there is little pressure on a tire it will almost lock up, but with crawling there are always enormous pressures on the tires so it would never lock and never help out.

10-24-2005, 10:29 PM	#7
RCMFMaxxMan RCC Addict Join Date: Jun 2004 Location: ORegon Posts: 1,002	yeah sorry i meant torsen. I understand i think...that they only go into effect with low amounts of pressure. is this correct?

10-25-2005, 04:22 PM	#10
RCMFMaxxMan RCC Addict Join Date: Jun 2004 Location: ORegon Posts: 1,002	wait doesn't it just send the power to the tire with MORE traction (the only one that really needs it)?

10-25-2005, 05:13 PM	#11
monsterjeepn Newbie Join Date: Oct 2005 Location: Lemon valley, Reno Posts: 25	kk u guys i got it... at least i think i do... i know this is at least a diff that is similar to a torsen but not sure if im gettin somethin mixed up . a torsen diff forces both axles to turn at the same time, however they may turn at different rates as long as BOTH are turning... i.e: if one stops the other has to, but they will act as an open diff with respect to turning and such. basically what the torsen does is let the axle shafts turn in opposite directions with respect to each other (through a series of opposing worm gears), but since the whole unit is turning in one direction, it appears that they are just turning at different rates. hope this clears some of the confusion up... oh and of course corrections are welcome... as long as they are CORRECT

10-25-2005, 07:45 PM	#13
EeePee MODERATOR™ Join Date: Jul 2004 Location: Ohio Posts: 18,928	Tire in the air, Torsen doesn't work at all.

10-26-2005, 04:33 AM	#15
EeePee MODERATOR™ Join Date: Jul 2004 Location: Ohio Posts: 18,928	Quaife differentials are Torsen types, they don't work with one tire in the air. That was my point of reference. (Been racing real cars for 8 years)

10-26-2005, 10:40 AM	#17
moonbuggy Quarry Creeper Join Date: Jun 2004 Location: Ventura Posts: 326	so some of you say it acts like a automatic locker and others say the same thing except it won't work when one tire is off terra firma, we both can't be right. I think I'll go ask Jeeves

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10-26-2005, 10:46 AM	#18
moonbuggy Quarry Creeper Join Date: Jun 2004 Location: Ventura Posts: 326	okay all of the ask jeeves links said same thing, won't work when a tire is off the ground. EDIT: P.S. look at the graph of performance vs. traction in Jason's link and you will see when traction equals zero (all the way to the left) efficiency drops to zero as well. Meaning it won't work!!

10-26-2005, 12:40 PM	#19
Grizzly4x4 PapaGriz Yo Join Date: Apr 2004 Location: In the garage building the wife a crawler Posts: 13,137	First of all. If torsens were superior to lockers and spools we all be using them on our 1:1 trail rigs and there would be no need for air/electric lockers. I can see where a worm gear diff might lock everything up but who makes one? A torsen diff (helical cut gear type) will, at some point, send all the power to the tire with no traction. Does this mean that nobody should try the torsen diff for the Mad Force axles? Heck no, I would love to see someone try it.

10-26-2005, 01:37 PM	#20
Micropuller Newbie Join Date: May 2005 Location: Holland Posts: 21	A torsen diff has a gear ratio. If the ratio is 4:1, this means that the diff will send up to 4 times the torque to the wheel with the most grip. If the tires have equal grip, the torque will be divided 50/50. If one wheel is in the air, the diff will send 4 times the torque to the other wheel and 4 x 0 = 0 Humvee's are als equipped with torsen diffs. During training, the students are tought to put their foot on the brake when the vehicle lifts a wheel.

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