MiniRX7

Just to confirm..

My old 2k2 and my 2k3 both exhibit behaviours indicating HLSD exists.

When i push it hard into a turn i end up with understeer as both wheels start spinning crazy... I don't ever get one wheel spinnning on the inside, so i believe both my 2k2 and 2k3 have HLSD..

Apparently if you have drilled pedals, that means you have HLSD..

I have seen some 2k2's with 6 speeds that do not have drilled pedals indicating an older batch..

ED

Stereodude

So does the metal plate on the firewall by the driver's side windsheild wiper. If it says RS6F51A you don't have HLSD. If it says RS6F51H you have it.

Stereodude

I did some of my testing at 2000RPM. There is a pile of TQ from the engine at 2k RPM. Popping the clutch in 1st doesn't neccesarily prove anything. I could leave two strips of rubber in 2 previous cars I drove that didn't have any sort of LSD.

The slippery surface test is going to be the best one. Put one wheel on a surface with a drastically lower coefficient of friction than the other. Launch hard and see what happens. The HLSD should send almost all of the engine's power to the wheel that has more traction and the car should pull foward hard.

It would really help if you guys could try to duplicate this testing. Wet soggy grass works, ice works, slimy mud works, etc. No matter what part of North America you live in you should be able to stage some testing that will allow you to test under the above mentioned conditions.

MaximaMan77

Did I mention 2K in my post?...

Anyway, yes 2k has a lot of TQ at WOT. How long are you going to stay at 2k while at WOT? .02 sec or less?

There is a BIG difference between TQ at 2k while the butterfly in the TB is wide open at WOT and at 2k and holding under no load with the butterfly 1/3 or less open. And this isn't a bolted differential we're talking about either, we all know a locked diff. is not practical.

**Why you would even think that nailing it in a turn is good proof it works I don't know. The whole purpose for the HLSD is for straight line driving anyway, at launch...**
Edit: high speed turning is what thiis for also my bad but any time your on the gas truning or not the HLSD should be working if you have it.

To get a good test the way you did it is not safe! And that would be to put the board under 1 wheel at idle with more force than to just to stop the tire from moving then have the driver nail the gas. Then you will either have the board RIPPED from your hands as it's thrown back at you or you'll watch the car fly off the stands. I have a feeling that it will be a combination of both and you'd be lucky to just end up on you azz and not be really hurt. Oh and those stands will really F'up the bottom of your car as it continues to hop and chirp the tires till the driver hits the brakes.

This whole topic has been stupid I just waited till you guys figured out the test you did was useless.

Again find a nice smooth tarred parking lot with just you in the car and get the revs up and dump the clutch then floor it, try to burn it at least 10 feet. (If it starts hopping let off the gas) Then get out and look at the skid marks. If you've got 2 nice burn marks then all is good. If you start with 2 and it transfers over to one of the wheels (usually the passenger side) then you got F'd by the dealer at the time of purchase.

SR20DEN

iTrader: (7)

You could help us by doing the test displayed in the video. We need a few more people with HLSD to do that to confirm ours are working properly.

MaximaMan77

Matt please explain how this test proves anything, in a no load low TQ manner. I'd really like to see where your coming from with this.

High speed turning and straight line launching is where this thing is supposed to shine. When the tires are off the ground the no load tire will always spin like that HLSD or not.

SR20DEN

iTrader: (7)

It was supposed to prove that his was broken. We both assumed the HLSD worked like a one way diff that you would find in the front end of a RC car. And since his did not we assumed his was broken. Now I discover that mine does the same thing so I want other HLSD owners to help me prove the validity of the test one way or the other. If we all prove that the test is bogus we will just have to come up with something valid. And we want to know what really makes this thing tick. What causes it to lock up?

Stereodude

Apparently you haven't been reading this thread too closely. Re-read what you quoted again and again until it sinks in.

The thread is how to determine the HLSD in the car is working properly or not. Not about the dealer screwing you over at the time of sale.

SR20DEN

iTrader: (7)

Yeah, you're right.

We're just a bunch of uneducated idiots.

Stereodude

Yes, we'll all just go out and do burnouts in the bays of our dealers to to check and make sure our HLSD is working.

MaximaMan77

No you are all not F'ing idiots, and I didn't mean to say this topic is stupid. Just that this test is stupid. The methodology used in this test is not sound.

In the RC cars I had, my last one was a 4wd touring car with a 300ZX body , if you grabbed or stopped a wheel from spinning it would transfer to power to the opposite wheel connected to the diff. The more power that was supplied the more force it took to stop the wheel. This test is the equivalent of doing the same test at a VERY low power on an RC car.

Lets assume that the current supplied to the motor is the same as the air supplied to our engine. The more current supplied the more TQ produced. This test you're doing is like trying it on an RC car with your finger pulling back 1/8 or less on the trigger.

There is no way the engine is supplying the TQ at 2K you'd see on a dyno with your foot to the floor because the TB is probably almost closed when you're holding steady at that rpm.

Maybe I'm an idiot, because I can't think of another way to try and test whether the HLSD is working or not than to try and see if you'll get a power transfer under load. Trying to induce a transfer in a manner that would prove anything while the car is on jack stands is just not safe.

So how do you try and induce a power transfer under load that leaves visual evidence either during or after the fact?

SR20DEN

iTrader: (7)

Have you ever had a one way diff in a RC car?

MaximaMan77

If I'm not mistaken 1 way diff's were popular in gas cars and no I haven't. And it was usually done with a 1 way bearing. http://www.rctek.com/general/differe...they_work.html

I would think our diff works very similar to this http://www.globalwest.net/torsen_tra...fferential.htm

You can also find info here http://www.houseofthud.com/differentials.htm#quattro

MaximaMan77

The cars I had were either open or ball diff's

MaximaMan77

From how stuff works:

The Torsen (from Torque Sensing) works as an open differential when the amount of torque going to each wheel is equal. As soon as one wheel starts to lose traction, the difference in torque causes the gears in the Torsen differential to bind together. The design of the gears in the differential determines the torque bias ratio. For instance, if a particular Torsen differential is designed with a 5:1 bias ratio, it is capable of applying up to five times more torque to the wheel that has good traction.

Hummer!
The HMMVV, or Hummer, uses Torsen® differentials on the front and rear axles. The owner's manual for the Hummer proposes a novel solution to the problem of one wheel coming off the ground: Apply the brakes. By applying the brakes, torque is applied to the wheel that is in the air, and then five times that torque can go to the wheel with good traction.

These devices are often used in high-performance all-wheel-drive vehicles. Like the viscous coupling, they are often used to transfer power between the front and rear wheels. In this application, the Torsen is superior to the viscous coupling because it transfers torque to the stable wheels before the actual slipping occurs.

However, if one set of wheels loses traction completely, the Torsen differential will be unable to supply any torque to the other set of wheels. The bias ratio determines how much torque can be transferred, and five times zero is zero.

*TORSEN is a registered trademark of Zexel Torsen, Inc.

MaximaMan77

So there is your answer. Use the brake when pushing the board against one wheel.

MaximaMan77

I also admit I was wrong. It wasn't the HLSD that needed TQ. It's the free spinning wheel that does.

So this test should work to some extent if you use the brakes and gas at the same time. While I still don't think this is safe you should be able to burn some rubber to the board but if it grabs it's going to be thrown back at you.

SR20DEN

iTrader: (7)

Well that is what we are now trying to determine. It appears that if our units are not broken then there IS a torque minimum that has to be supplied in order for it to work. Based on what I previously knew of the Quaiff diff. I assumed it should operate similarly to a one way diff. like you would find in a RC car. And in theory it still does but under a slightly different set of circumstances.

Y2K2Driver

iTrader: (1)

I thought a HLSD behaved more like a Quiffe diff than a Torsen diff? Am I wrong here?

MaximaMan77

I believe it is very similar, Torsen's are just where I found better info.

When the free tire spins in this test the TQ is there it's just not acting on anything so it can't transfer the power to the tire with grip. Another way of doing this test, and maybe safer, would be to use 2 people with boards instead of useing the brakes. This way the guy in the seat just needs to hold a steady rpm then not move his foot, while one guy stops one tire with just enough force to stop it. Then the other guy puts some force on the other tire, when that this happens the tire that is stopped should start moving again.

Y2K2Driver

iTrader: (1)

I think the distinction between Quaffe and Torsen behavior is something that needs to be solidly answered before a proper test can be made. A Quaffe and Torsen diff are quite different. A Torsen diff can only transfer a preset multiple of the torque on one wheel to the other wheel. This is what you have been describing. However, a Quaffe diff does not have this limitation. Both are torque sensing and therefore transfer torque before slippage has occured. Now this is where things get interesting. If the HLSD behaved like a Quaffe then one would expect that the test performed would be valid. However, we have heard that a believed to be functioning HLSD behaved in the same manner. If that is really true, than the HLSD can not be thought of as a Quaffe diff. At this point in time though, we don't know if it like a Torsen diff either. I agree with the test that maximaman777 has proposed, using two boards to create a counteracting torque on each wheel should, if nothing else, at least give us some more info as to whether or not the HLSD behaves like a Torsen diff. It's worth trying in my opinion at least. Keep the info coming. I've been interested in the HLSD behavior since I bought the car and was quite displeased at the fact that the ESM had no info on it.

IceY2K1

iTrader: (3)

Useful reading on the LSD(Viscous) vs. Kaaz/Cusco(clutch type) vs. Quaife(Helical-gear):
http://www.sportcompactcarweb.com/pr...via/index.html

MaximaMan77

I'm pretty sure TQ sensing means there has to be some load on the wheels. A free spinning wheel has no TQ to sense.

IceY2K1

iTrader: (3)

I'm not sure of this, but I always thought TQ sensing meant the torque resulting from one side, ie input gear, spinning faster caused the diff gears shape to apply more force to the side with more traction(I guess depends on design?).

MaximaMan77

This is true. Only that BOTH wheels MUST have some amount of load on them. If one can spin freely then it is not putting out any torque. Just like a stripped bolt, you can apply as much torque to the head of the bolt as you want but it's not reacting with anything so it just spins.

"However, if one set of wheels loses traction completely, the Torsen differential will be unable to supply any torque to the other set of wheels." This also applies to the Quiffe only in this case it's not for 4WD but it's the same principal.

While I understand how this works I'm not sure how to put it into words.

I guess the easiest way to say it is; There is nothing pushing back on the gears for it to "sense" the loss so the wheel just keeps spinning at about twice the speed it normally would.

Stereodude

A few things...

1) We don't have a Torsen Differential. We have a Quaife style differential.

2) A freely spinning wheel still uses some torque. There is air resistance, the brakes dragging and other drag in the driveline. Now, I suppose it's possible that it doesn't use enough for the HLSD to engage, but I don't have any way of knowing that.

Wet grass, or mud should have enough resistance to cause the HLSD to engage, even if it doesn't in the air.

Stereodude

I was under the impression that TQ sensing meant that the differential sensed the torque unloading into a spinning wheel and sent it to the other wheel.

MaximaMan77

The Quaife torque biasing differential enables your car to accelerate quicker and corner faster. How?

By getting the power to the ground!

The Quaife Differential powers both drive wheels under nearly all conditions, instead of just one. With an ordinary open differential, standard on most cars, a lot of precious power is wasted during wheelspin under acceleration. This happens because the open differential shifts power to the wheel with less grip (along the path of least resistance). The Quaife, however, does just the opposite. It senses which wheel has the better grip, and biases the power to that wheel. It does this smoothly and constantly, and without ever completely removing power from the other wheel.

In drag-race style, straight-line acceleration runs, this results in a close to ideal 50/50 power split to both drive wheels, resulting in essentially twice the grip of an ordinary differential (they don't call open diffs "peglegs" for nothing).

In cornering, while accelerating out of a turn, the Quaife biases power to the outside wheel, reducing inside-wheel spin. This allows the driver to begin accelerating earlier, exiting the corner at a higher speed.

The Quaife also controls loss of traction when the front wheels are on slippery surfaces such as ice and snow or mud, providing the appropriate biased traction needed to overcome these adverse conditions. The Quaife Differential provides constant and infinitely variable drive. Power is transferred automatically without the use of normal friction pads or plates seen in other limited-slip designs.

The Quaife's unique design offers maximum traction, improves handling and steering, and puts the power where it is needed most. A definite advantage whether on the track or on the street.

The Quaife is extremely strong and durable and since the Quaife is gear operated, it has no plates or clutches that can wear out and need costly replacement.

The Quaife is great for street driving or racing. Racers don't have to put up with locking mechanisms or spools that tear the steering wheel out of their hands when cornering. Because it behaves like an open differential during ordinary driving, street drivers will have trouble telling it's there until pushing the car's limits.

The Quaife has been proven in everything from SCCA Rally to Formula 1. It provides autocrossers with such an advantage, it has become "required" equipment for a winning effort.

Every Quaife ATB Differential comes with something else other's don't have:
a Limited Lifetime Warranty. This warranty applies even when raced !


1) Torsen & Quaife are somewhat similar in that they both use a helical gear system. Quaife's marketing just doesn't say anything about a completely unloaded wheel. That's why I quoted Torsen.

2a) The TQ would probably be measured in low oz/in rather than ft/lbs in your test.

2b) No it doesn't put out enough force for the HLSD to engage.

As you can see above they say "under nearly all conditions". Also when they talk about slippery surfaces they use the word wheels in plural, they're talking about both wheels being on a slippery surface. The word biased is also used. A completely unloaded wheel, one the ground or not, has no "bias" for the system to use. The amount of load on the wheel is not enough to push back against the gears, hence it goes open and one side unloads.

I hope this helps. This type diff's while not perfect for every single circumstance it is a vast improvement.

Stereodude

Why do you insist on turning this into a ****ing match?

You're trying to disect the language to make it say something it doesn't. Instead of arguing with me about the semantics of the language they used, go take your car out and try my test on the ground and report back.

2k2kev

is it time for me to say 'told you so' yet?

SR20DEN

iTrader: (7)

If you people aren't going to help then please unsubscribe from this thread. None of you have proven ANYTHING. We don't need anymore opinions. We need proven facts.

MaximaMan77

I am not trying to have an b!tching contest with you. I am trying to expain to you why an unloaded wheel in your test will not allow you to confirm you have a HLSD. I know I have 1, and I know it's working fine. If you don't want to put your car back on stands and put a load on both tires so you can confirm in your mind that you really to have 1 that's fine by me but that's how you'll find out.

SR20DEN

iTrader: (7)

If you have one and know it is working right then why not show us one more example?

MaximaMan77

Anyone with a 5 or 6spd 5th gen and no HLSD wanna meet me in ATL somewhere. I don't have a vid cam so that will be helpfull too.

Stereodude

No, because you're not right. What you're saying is not correct. The whole idea of a LSD is to transfer power from the wheel that slips to the one that doesn't. When a wheel starts slipping the TQ on it rapidly drops. If you needed an increase in TQ to engage the LSD it never would.

The problem is too many of you think the HLSD is like a Torsen diff which has a multiplier ratio (like 5:1). If you can't put any torque down to one of the wheels you can't put any torque down to the other wheel either. 5 x 0 = 0. This isn't the case with the HLSD. It doesn't work that way.

Stereodude

You still haven't been reading this thread. For the last time, I know my car has one, but I firmly believe it's not working properly anymore. This thread is all about how to test one and see if it's working or not.

MaximaMan77

I just emailed Quaife. I'll keep my mouth shut till I get there reply. I asked about an unloaded tire & a good test to show proper function.

SR20DEN

iTrader: (7)

I was just looking for their webside to call them. I will wait for your response.

MaximaMan77

If they don't resopnd by 4:30 our time Matt I'll call out there. I'm hoping to get an email that I can post.

MaximaMan77

I'm really not trying to one up you guys here and as frustrated you were with the responses you getting I was with myself with my inability to word how this works. I do understand it but now how to explain it as said previously.

Anyway here's what they said and good luck with your testing

Adam,

Thank you for your inquiry. If one drive wheel is off the ground, the Quaife ATB diff will act like an open differential. There needs to be some resistance on both drive wheels in order for the Quaife unit to function properly.

As far as a test goes, you can do a burn-out (which should leave 2 tire tracks) or put one wheel on dirt/ice and one on tarmac and than accelerate. They're both a bit unscientific but probably the best way of determining without tearing out the transaxle.

Regards,

Ralph Hollack

----- Original Message -----
From: Adam 77
To: info@quaifeamerica.com
Sent: Thursday, November 13, 2003 7:39 AM
Subject: Quick question on power transfer.


Hi,

I was wanting to know if when using your ATB on a front wheel drive car if one tire is completely unloaded, either off the ground or on ice from a stop, will there still be a power transfer to a wheel with grip or if the unloaded tire will just spin freely.

Also do you know of a good test one could do to prove the functioning of the ATB.

Thank you for your help,
Adam