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Old 06-04-2017, 08:20 PM   #127
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Originally Posted by Scrappydoo View Post
Why are you assembling it on a cooker hob?
No worries, it's an induction hob so will not heat up with plastic pans.
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Old 06-04-2017, 08:22 PM   #128
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Originally Posted by Tcoat View Post
In the case if a 1BP (baby power) engine such as this the fluids could be expelled by both the intake and exhaust. Sometimes simultaneously.
At 11 months smart pit crews insist on a protective suit for one end. Unfortunately, there have been no effective restraining devices developed for the other end. HANS has proved to provide insufficient coverage.
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Old 06-04-2017, 08:28 PM   #129
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Originally Posted by Ultramaroon View Post
I think I see your point. I have some more studying to do. Wish I had one to disassemble.
Torsen separates differentiation from torque transfer. The drive wheels are free to differentiate even if torque is being transferred across the diff.

This is why wheel speed isn't important in understanding how a Torsen works. Also why this is the only type of diff to fit into a fwd chassis. Imagine how a clutch type LSD operates in a fwd car if the driver tries to change the steering angle under hard acceleration and then consider how a Torsen equipped car would behave.

Some think a Torsen limits wheelspin in a progressive way, as does a clutch type LSD. This is not the case. A Torsen prevents wheelspin completely until the bias ratio is exceeded. There is no waiting. As soon as the torque starts to split unequally the Torsen "locks up" from a torque delivery perspective. It continues to allow driven wheel differentiation at all times, but that force has to originate at the wheel because the diff only allows the side gear to drive the "spider gears", never in the other direction.

In very low grip situations such as snow or ice a high bias ratio Torsen can cause quite abrupt loss of traction. Under acceleration both drive wheels will spin readily. The rear axle will oversteer abruptly if the throttle is opened just a little bit too rapidly. Because it transfers torque before allowing any wheelspin the transition from grip to very little grip can be quite immediate.

The Torsen is an ingenious invention. Gleasman must have been a fascinating mind to meet. I prefer not to refer to the Torsen as a limited slip differential in part because it prevents drive wheel slip completely until there insufficient traction. The Torsen in action doesn't just limit slip. The flip side of this locking action is that no grip means no limiting of the slip. In that sense the Torsen acts like a locker diff. Unlike a locker it simultaneously allows the driven wheels to differentiate in a forwards direction. Because the helical gears cannot drive the side gears they effectively lock if torque is applied to the diff carrier. However, if the driven wheels need to differentiate the side gear can drive the helical pinion gears allowing the outside wheel to continue to travel faster than the inside wheel in a corner all while not wasting any usable engine torque. Ingenious.

Last edited by Gforce; 06-04-2017 at 10:51 PM.
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Old 06-04-2017, 08:34 PM   #130
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Originally Posted by Sapphireho View Post
That's the Mattel 8000 rear end. Don't worry, it's well built.
And note the capacious ballast tray to allow for corner weight balancing.

Anyone yet caught the full comedic impact of the diversion off topic here?

The subject line of the thread has just acquired a whole new level of meaning...just don't add limited slip to the discussion.
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Old 06-04-2017, 08:48 PM   #131
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Originally Posted by Scrappydoo View Post
Why are you assembling it on a cooker hob?
Well, now ..... @Tcoat asked the same question.

Since it's made of plastic and most likely made in China, the parts didn't seem to want to fit together very good. So, I just heated them up over a warm burner and smashed them together, with the help of a large rubber hammer.

I kept another burner on HI with a flat headed screwdriver heating up, which I used to "weld" the pieces together ...... thus eliminating the need for those poorly made screws and bolts that I have a hard time figuring out which ones goes where.

Bubba taught me that trick ......


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Old 06-04-2017, 08:58 PM   #132
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Originally Posted by Gforce View Post
The first of those on the market was the Big Wheel I believe. The Classic trike of trike suffers from terminal oversteer, or more usually terminal overturning moment. The Big Wheel eliminated the overturning moment (unless the fat kid town the block stole your trike) and released the terrifying drift mode.
You are quite correct. How did we survive on tricycles without knee and arm pads, helmets and seat belts ......

Ahhh...... but some didn't learn the technique of dealing with the oversteer so good ...and suffered some head injuries ........ right @Scrappydoo .......


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Old 06-04-2017, 10:22 PM   #133
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Originally Posted by funwheeldrive View Post
Wouldn't riding with a donut on the rear for an extended amount of time cause some harm to the LSD?
not in the way you think.

not in the way that is being described here. If you affect the LSD to an extent that damage is causing noticable sway, that LSD is so far gone it wouldn't even be drivable/very noticable during turns etc.

I personally think the OP is either poor or a moron for not following good driving practices.

OP you can fight me if you want. You'll lose.
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Old 06-04-2017, 10:24 PM   #134
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Originally Posted by Gforce View Post
Torsen separates differentiation from torque transfer. The drive wheels are free to differentiate even if torque is being transferred across the diff.

This is why wheel speed isn't important in understanding how a Torsen works. Also why this is the only type of diff to fit into a fwd chassis. Imagine how a clutch type LSD operates in a fwd car if the driver tries to change the steering angle under hard acceleration and then consider how a Torsen equipped car would behave.

Some think a Torsen limits wheelspin in a progressive way, as does a clutch type LSD. This is not the case. A Torsen prevents wheelspin completely until the bias ratio is exceeded. There is no waiting. As soon as the torque starts to split unequally the Torsen "locks up" from a torque delivery perspective. It continues to allow driven wheel differentiation at all times, but that force has to originate at the wheel because the diff only allows the side gear to drive the "spider gears", never in the other direction.

In very low grip situations such as snow or ice a high bias ratio Torsen can cause quite abrupt loss of traction. Under acceleration both drive wheels will spin readily. The rear axle will oversteer abruptly if the throttle is opened just a little bit too rapidly. Because it transfers torque before allowing any wheelspin the transition from grip to very little grip can be quite immediate.

The Torsen is ingenious invention. Gleasman must have been a fascinating mind to meet. I prefer not to refer to the Torsen as a limited slip differential in part because it prevents drive wheel slip completely until there insufficient traction. The Torsen in action doesn't just limit slip. The flip side of this locking action is that no grip means no limiting if the slip. In that sense the Torsen acts like a locker diff. Unlike a locker it simultaneously allows the driven wheels to differentiate in a forewards direction. Because the helical gears cannot drive the side gears they effectively lock if torque is applied to the diff carrier. However, if the driven wheels need to differentiate the side gear can drive the helical pinion gears allowing the outside wheel to continue to travel faster than the inside wheel in a corner all while not wasting any usable engine torque. Ingenious.
Thank you for this wonderful breakdown. I for one had little idea that the system was different significantly than the standard production LSD
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Old 06-04-2017, 10:53 PM   #135
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Originally Posted by humfrz View Post
OK, Folks ....... the "beast" is built. The engine is at the tuners getting rested and charged up. The big race will start at 0730 Monday morning.

Note the racetrack has a nice straight away, a 90 degree curve is behind me to my left with more straight away.

As you can see in the close up, this machine has several noteworthy features:

* its a roadster, with a soft top (which also acts as a roll bar)

* the front (drive) axle can be locked or unlocked ..... blocking power from the engine (freewheeling .... eg Georgia overdrive)

* the rack & pinion steering can be done by the driver or co-pilot

* the seat is made by Recaro and has a 5 point hitch

* dash mounted tray for a bottle and snacks

* handy tray for co-pilot's water, snacks, cell phone

* ample trunk space for spare diapers, burp clothes, and general clean up materials in case of a blow out from either end

* duel, positive lock rear axle (parking brakes or for drifting)

* HD skid plate for off road protection

* the co-pilot's handle and other parts can be easily removed for it to convert to trike mode


time for pa-pa's nap ...... I've had a busy morning .....
You are way far gone into grandpa paradise. I won't reveal how I know that.
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Old 06-05-2017, 05:04 PM   #136
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Originally Posted by humfrz View Post
OK, Folks ....... the "beast" is built. The engine is at the tuners getting rested and charged up. The big race will start at 0730 Monday morning.

Note the racetrack has a nice straight away, a 90 degree curve is behind me to my left with more straight away.

As you can see in the close up, this machine has several noteworthy features:

* its a roadster, with a soft top (which also acts as a roll bar)

* the front (drive) axle can be locked or unlocked ..... blocking power from the engine (freewheeling .... eg Georgia overdrive)

* the rack & pinion steering can be done by the driver or co-pilot

* the seat is made by Recaro and has a 5 point hitch

* dash mounted tray for a bottle and snacks

* handy tray for co-pilot's water, snacks, cell phone

* ample trunk space for spare diapers, burp clothes, and general clean up materials in case of a blow out from either end

* duel, positive lock rear axle (parking brakes or for drifting)

* HD skid plate for off road protection

* the co-pilot's handle and other parts can be easily removed for it to convert to trike mode


time for pa-pa's nap ...... I've had a busy morning .....
that downforce though
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Old 06-05-2017, 09:35 PM   #137
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Originally Posted by Kronos View Post
So the short of it is my last set of tires I wore down till they were nearly bald and then I ran over a nail so I had to write on a donut for about a week. I just got new tires installed Kumho ecsta31 and now my car sways like a boat on the highway. Anything above 45. Any thoughts?
When I installed my SPC rear camber arms, the alignment was WAY off after (you could eyeball it it was so off!) and I drove to an alignment shop to get everything pointing like it should. At speeds over 45 the rear end would sway around badly. Maybe even like a boat! If you have adjustable rear camber, see if it might not be off some.

-check pressures
-make sure the tires are mounted in the correct direction
-if everything else is OK, you may have gotten bad tires. It happens and it can be very dangerous. Jack the car up and inspect those rear tires
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Old 06-06-2017, 05:09 PM   #138
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Originally Posted by Gforce View Post
Torsen separates differentiation from torque transfer. The drive wheels are free to differentiate even if torque is being transferred across the diff.
The same is true of most limited slips, including clutch-types.

Quote:
This is why wheel speed isn't important in understanding how a Torsen works.
Wheelspeed doesn't dictate the amount of "lock" or torque bias, but it's not totally unimportant.
(FTR "wheelspeed" doesn't dictate how much a clutch-type locks or biases torque, either.)

In both the clutch type and the torsen limited slips, torque is transferred from one output to the other via friction. In the clutch-type the friction is between clutch plates, in the Torsen T2 it's between the helical gears and the casing resulting from axial force in these gears.

If you have different rear tire sizes, rear outputs will be rotating at different speeds and this friction will generate heat and wear parts at a greatly increased rate.

Running a smaller-diameter space-saver spare on the drive end of the car with a either type is not a good idea. Tremendously greater heat and wear due to the different rotational speeds of the outputs. They're only intended/designed to operate like that briefly while cornering, not continuously.

Quote:
Also why this is the only type of diff to fit into a fwd chassis. Imagine how a clutch type LSD operates in a fwd car if the driver tries to change the steering angle under hard acceleration and then consider how a Torsen equipped car would behave.
A Salisbury clutch-type with low breakaway torque doesn't behave terribly differently from a Torsen. Can be smoother, even...

Quote:
Some think a Torsen limits wheelspin in a progressive way, as does a clutch type LSD. This is not the case. A Torsen prevents wheelspin completely until the bias ratio is exceeded. There is no waiting.
There is no waiting with a Salisbury/ramp clutch-type either. In both cases the application of torque increases "lock" or bias, so they are both "progressive" in this sense. And in both cases friction is the mechanism for transferring torque from the wheel that wants to spin to the wheel with grip.

Torsens can and do WEAR. And driving on one for a significant amount of time/distance with different diameter tires will accelerate this wear. But I don't think 50 miles normal driving would do anything catastrophic...
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Old 06-07-2017, 03:24 PM   #139
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Thank you for this wonderful breakdown. I for one had little idea that the system was different significantly than the standard production LSD
You do realize you just thanked Ubersuber for technical "knowledge" right?
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Old 06-07-2017, 03:29 PM   #140
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Torsens can and do WEAR. And driving on one for a significant amount of time/distance with different diameter tires will accelerate this wear. But I don't think 50 miles normal driving would do anything catastrophic...

Thank you! Glad to hear there are others that understand how they actually work.
This was the whole statement from the beginning. The original question was will it cause harm with "extended" use. Not will it cause harm.
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