I dont want to be 1WD anymore!

[johnc]

Regarding Quaife's

 

1. They DO wear out.

 

I've yet to wear one out (I have two) and have been running one since 1998.

 

2. They DO need to be readjusted from time to time.

 

No internal adjustments except for preload.

 

3. They generate LOTS of heat since there is no friction surface, just metal on metal.

 

Heat is also generated because of work. The work is the gears doing their job and generating shear loads in the diff fluid.

 

4. When a tire comes off the ground the gear type will transfer ALL of the power to that wheel instantaneously, in a Z this is bad because when that wheel comes down you've now broken a stub axle. Clutch style doesn't do that.

 

True for the first part and the wheel coming off the ground is a suspension tuning issue, not a Quaife problem. If you're lifting the inside rear wheel off the ground you will tend to break stub axles regardless of the type of LSD>

 

5. They slip! John Coffey has said on a few occasions that he's had problems with them slipping in high speed corners.

 

The unit didnt' slip. It went open way too easily. Some of that was suspension tuning on my 240 and some was a preload issue with the Quaife.

 

He's also said that Quaiffe couldn't fix them. He did have another place to send them to that could get them to not slip anymore (EMI?) I've heard this same complaint from other racers now too.

 

Quaife didn't fix it because they said nothing was wrong with the unit. Taylor Race Engineering slightly modified the unit for my applicaiton by increasing the preload. Also, softening the rear roll rate helped eliminate the problem.

 

6. Although I have to admit I haven't heard it in regards to the Quaiffe, I would estimate that I used to get 15-20 calls PER WEEK from Camaro owners with gear driven units that had just done their best grenade impression when I was selling diff parts.

 

Haven't heard of a Quaife failing yet.

 

JohnC has said before how much heat the Quaiffe generates. Heat means friction, thus something has to be wearing.

 

Heat can be created from friction and from work. The Quaife generates its heat from work, not friction. The shear loads on the diff fluid are very high and that's what creates the heat.

 

The big "issue" with the Quaife is that you have to tune your car's suspension to take full advantage of it. The rear roll rate needs to be softened to keep the rear planted. This affects how the car handles and how you drive the car.

 

A typical west coast Z is setup neutral to slightly oversteering with a pretty stiff rear roll rate. This allows the car to fly into corners and carry speed through mid corner. But, it affects corner exit and puttung the power down.

 

With a Quaife until the car should be setup to be neutral to understeering and the car enters corners slower but man, you can just plant your foot (even with 300+ hp like my car) once you're pointed at the apex. That's a typical east cost Z setup.

 

FYI... I just called Terry at Taylor Race and the retail price for the R180 115mm ID Quaife ATB is $1,445, which is $150 more then the original 1998 retail price of $1,295. Unfortunately, they are NLA until Quaife gets another group order of 25 or more.

[Savage42]

Like a couple others, I'm sold on and have always used clutch type LSDs for over a decade. A buddy spent money to put a Quaiffe in his built Spitfire and had serious inside tire spin in tight corners at an autocross. He wasn't too happy about it. Bottom line is that we all want power to both rear wheels. I'd say the $500 Power Brute from http://www.differentials.com or Reider Racing is the most cost effective way to go. Add $100 for setup and you are there for 1/3 the cost of a Quaiffe. Of course, I've built cars for street, autocross, hillclimb & track days, so you "straight-liners" may have a different perspective. It took a decade to wear out my LSD and it wasn't the clutches that wore but the output bearings. Always ran Amzoil and had a ton of race mileage on it, along with street driving 50k+ miles.

[JMortensen]

I've yet to wear one out (I have two) and have been running one since 1998.

That's impressive.

 

No internal adjustments except for preload.

Preload is the same thing you're adjusting in a clutch type by changing the thickness of the clutch pack, and you adjust it because of wear. But I ALWAYS hear the Quaiffe proponents talking about how it never wears, and never needs adjusting!!!

 

Heat is also generated because of work. The work is the gears doing their job and generating shear loads in the diff fluid.

Friction comes from work in the case of the ring and pinion or transmission gears, this is true. But when you are spreading the gears against the case to create the resistance instead of using the weight of the vehicle as in the ring and pinion or trans I have a harder time seeing how it is the meshing of the gears that creates the heat in the Quaiffe. There is no friction surface to increase the friction at the gear tips, so any increased friction comes from the tip of the gear digging into the case, which seems like it would be the primary heat generator.

 

True for the first part and the wheel coming off the ground is a suspension tuning issue, not a Quaife problem. If you're lifting the inside rear wheel off the ground you will tend to break stub axles regardless of the type of LSD>

That's true, I've had my clutch style slip going into my old severely slanted driveway. But the one engineer I know who really turned me off on the Quaiffe kept breaking axles on his Midget, and didn't break them anymore when he went back to a clutch type. When I first became aware of them, I asked on the IZCC list, and several people who had switched to it had already broken stub axles. What that is worth, I don't know.

 

The unit didnt' slip. It went open way too easily. Some of that was suspension tuning on my 240 and some was a preload issue with the Quaife.

Which sounds the same to me as having a worn out clutch type. Too little preload and it "goes open" and the inside tire spins. I don't see the difference.

 

Quaife didn't fix it because they said nothing was wrong with the unit. Taylor Race Engineering slightly modified the unit for my applicaiton by increasing the preload. Also, softening the rear roll rate helped eliminate the problem.

OK, so you can tune around it. I'm sure you could do the same with a worn out clutch type. If the inside tire never got light it due to less rear roll stiffness, it would be less likely to "go open" too.

 

Haven't heard of a Quaife failing yet.

Also very impressive, and if it did fail they'd replace it, even if you were racing. I can't argue with that.

 

Heat can be created from friction and from work. The Quaife generates its heat from work, not friction. The shear loads on the diff fluid are very high and that's what creates the heat.

Not sure I'm on board with this one yet.

 

With a Quaife until the car should be setup to be neutral to understeering and the car enters corners slower but man, you can just plant your foot (even with 300+ hp like my car) once you're pointed at the apex. That's a typical east cost Z setup.

That part sounds good, except I like my car setup west coast style.

 

FYI... I just called Terry at Taylor Race and the retail price for the R180 115mm ID Quaife ATB is $1,445, which is $150 more then the original 1998 retail price of $1,295. Unfortunately, they are NLA until Quaife gets another group order of 25 or more.

About $1000 too much IMO.

 

John's car is the fastest Z I've ever heard of, and he uses the Quaiffe. That says something for their performance. All I'm saying is that the gear units DO wear, they DO require adjustment, they do "go open" and they do cost too much. IMHO.

 

The other question for me is that if the gear driven units are so wonderful, why are they widely considered the cheap crappy option for domestic racers? Maybe there is a design difference that makes the Quaiffe superior to the Torsen or the Tru-Trak. I can't see anything obvious in the exploded views.

[Drax240z]

F1 used viscous diffs up until 1998 apparently.

 

spreading the gears against the case to create the resistance

 

Again you are assuming there are no needle bearings between the gear and the case. Both Torsen units I have had apart had these bearings to reduce the friction caused by sideloading the gears.

 

I am still not sure what you guys are talking about when you say 'preload' in the Quaife. Are you equating this to TBR?

 

I have a harder time seeing how it is the meshing of the gears that creates the heat in the Quaiffe

 

All gears have friction, and all friction creates heat. Same deal goes in a regular open differential.

 

The unit didnt' slip. It went open way too easily.

 

Answering my own questions here, if it goes open too easily than the TBR is too low for your application. I couldn't figure out any way a Torsen type diff could slip without having sheared the teeth off the gears.

 

Which sounds the same to me as having a worn out clutch type. Too little preload and it "goes open" and the inside tire spins. I don't see the difference.

 

The difference is that the quaife isn't worn out, it is just not adjusted correctly for the given application. Once it's adjusted correctly you can forget about it except for an oil change here and there. (hence the no adjustment mumbo-jumbo... should read: "needs no adjustment after it has been adjusted correctly")

 

FYI... I just called Terry at Taylor Race and the retail price for the R180 115mm ID Quaife ATB is $1,445, which is $150 more then the original 1998 retail price of $1,295. Unfortunately, they are NLA until Quaife gets another group order of 25 or more

 

Did you happen to ask about a R200 unit as well? Those prices seem quite reasonable and don't correspond with what I've been told by my suppliers.

[JMortensen]

Drax, I don't know what Torsen diffs you were looking at, but you've got me confused as to how the ones that you opened up worked.

 

You've got side gears with helical sections on the inboard side. The helical sections drive 3 long rotini pasta looking gears which sit in the middle. As you put power to the diff, the side gears want to move laterally before they actually drive the axles. When they move they drive the long gears against the inside of the case. Once they are up against the case and they cannot move anymore, then differentiation can take place. When it does take place the inside wheel must overcome the friction created by the gears rubbing against the case.

 

The preload would be set by adjusting the side gear spacing so that the long gears are already engaged against the case.

 

Without the preload the units spin VERY easily, at least the ones I've played with. Not sure how the TBR is adjusted other than jamming the gears against the case harder. As I said before, I know that the Gold Trak had different helical gears you could install with different pitched teeth. I assumed that this meant that they would try to walk off of the side gears quicker and hit the case harder.

 

I've never seen the needle bearings you're referring to, so I don't know what to say about that. Seems counterproductive to the way the thing works to put a bearing on there.

 

EDIT--Maybe the bearing is there to keep the noise to a minimum? I know the Tru-Traks are noisy, especially when changing from right hand turns to left hand turns and vice versa, like in a slalom. They make all sorts of creaking and popping noises as the helical gears get driven into the case and then overcome that friction and start turning.

[HS30-H]

.... About $1000 too much IMO.

 

So you want the Quaife for around $500 then?

 

You must be kidding. The Quaife ATB is manufactured here in England - as you know - and you must also surely be aware that Quaife let their USA distributors sell them to you at prices MUCH cheaper than we can buy them here in the UK. You're getting a hugely preferential price' date=' and you still want it cheaper (!).

 

Have you checked out the $US to Pounds Sterling exchange rate recently? I can't see how Quaife can manufacture them here, ship them out to their US distributors ( paying US Import Duties and taxes along the way ) - who also presumably need to make a profit when they then sell them to you - and STILL make any money out of it.

 

Unless Quaife set up a manufacturing plant in Cuba and smuggle them over to you, I don't see how $500 would be achievable..........

 

Unless you are saying that they are only [i']worth[/i] $500.........

[Guest RCNSC]

....what have I started?

 

I'll just stick to my 1WD for now. I guess leaving two marks isn't THAT important.

[JMortensen]

So you want the Quaife for around $500 then?

Truth be told if they were $450 and the clutch type was $500, I'd spring for the clutch type.

 

You must be kidding. The Quaife ATB is manufactured here in England - as you know - and you must also surely be aware that Quaife let their USA distributors sell them to you at prices MUCH cheaper than we can buy them here in the UK. You're getting a hugely preferential price, and you still want it cheaper (!).

I wasn't aware that we were getting such a "bargain". I also want cheaper gas, BTW. Maybe that's crazy too, since you pay 3 times as much for it.

 

Have you checked out the $US to Pounds Sterling exchange rate recently? I can't see how Quaife can manufacture them here, ship them out to their US distributors ( paying US Import Duties and taxes along the way ) - who also presumably need to make a profit when they then sell them to you - and STILL make any money out of it.

 

Unless Quaife set up a manufacturing plant in Cuba and smuggle them over to you, I don't see how $500 would be achievable..........

Doesn't make me willing to pay more. Makes me want to buy something else. I'm not after a $25K OS Giken head either...

 

Unless you are saying that they are only worth $500.........

Exactly.

 

RCNSC--relax dude. We're just arguing. No one should be getting their feelings hurt here, or getting uptight at all.

[Savage42]

....what have I started?

 

I'll just stick to my 1WD for now. I guess leaving two marks isn't THAT important.

 

Of course leaving 2 long ass stripes on the ground is important!! It's a MUST! Only thing better is leaving 4 long stripes!!

[HS30-H]

Truth be told if they were $450 and the clutch type was $500' date=' I'd spring for the clutch type.

 

I wasn't aware that we were getting such a "bargain". I also want cheaper gas, BTW. Maybe that's crazy too, since you pay 3 times as much for it.

 

Doesn't make me willing to pay more. Makes me want to buy something else. I'm not after a $25K OS Giken head either...

 

Exactly.

[/quote']

 

If the clutch type was made in Japan - as I believe the ones you are referring to indeed are - and you were to get it for $500, then that would also be a preferential price ( or, if you prefer, a "bargain" ). Just like the price that your 1970 240Z sold for when it was new.

 

Most of the pump price that we pay for 'Gas' here in the UK is made up of taxes and duties. We don't like the price we pay for it sure enough, but the price of the Quaife ATB is NOT made up predominantly by taxes in the way that our pump petroleum is. I still think a $1500 Quaife ATB represents extraordinarily good value considering where it is manufactured.

 

I'm not after a $25k O.S.Giken head either, but I do understand why that would be a reasonable figure for them to charge for a kit. Like the cost of the Quaife ATB, its just simple economics.

 

Maybe a US-based company might like to start making some LSD units for the R180 and R200 diffs? As long as they were priced LESS than the Phantom Grip I'm sure they would do very well

 

Sounds like a perfect job for the "....birthplace of the machine tool."

[Tim240z]

....what have I started?

 

I'll just stick to my 1WD for now. I guess leaving two marks isn't THAT important.

 

Gee and this is one of the tamer threads......

[fl327]

....what have I started?

 

I'll just stick to my 1WD for now. I guess leaving two marks isn't THAT important.

 

Of course leaving 2 long ass stripes on the ground is important!! It's a MUST! Only thing better is leaving 4 long stripes!!

 

I got to drive a z with the nismo clutch lsd, its a good unit and yes after installation you are close to 1k invested if you get the unit new and have a skilled driveline shop install the unit into your carrier, but it changes the handling traits of the zcar like night and day, and it can make you a slideshow king! Only thing I like seeing than two long tracks is two long tracks seperated by the shifts Either way you go about getting an LSD diff, youre driving and handling will be changed for the better and I seriously doubt after a few thousand miles of driving it will you feel cheated. 500 for a used r200 may sound high, but put 500 miles on it assuming its in good condition and you will probably forget all about it. A change like this can turn a car you like a little into a car you love. It seems people with a lot of tracktime behind them are biased as to which unit they prefer and I find that to be only natural, and reading their various points of view is an education within itself.

[JMortensen]

I'm not after a $25k O.S.Giken head either, but I do understand why that would be a reasonable figure for them to charge for a kit. Like the cost of the Quaife ATB, its just simple economics.

 

I don't care if it's exchange rates, or labor prices or what, if I have to pay 3 times the value of any part, I'm not likely to buy it.

 

Maybe a US-based company might like to start making some LSD units for the R180 and R200 diffs? As long as they were priced LESS than the Phantom Grip I'm sure they would do very well

 

There are plenty of quality LSD manufacturers here that could make an equal or better unit cheaper, there is just not enough demand. I'd love to have a Dana or an Eaton or a Trac-Tech positraction. Seems that those crazy bastards running those businesses would rather make 50,000 8.5 GM LSD's than 500 Nissan ones.

 

I still think a $1500 Quaife ATB represents extraordinarily good value considering where it is manufactured.

 

That's where you and I disagree. I think that auto parts have a value that is not dictated by its country of manufacture, but rather by how good they are. So if there is no value gained I won't pay $50 for an Icelandic roll pin or $100 for a Siberian radiator cap, or $90 for a Ecuadorian ignition coil, or $1500 for a British LSD.

[johnc]

British LSD

 

Never tried British LSD...

[JMortensen]

That makes two of us, and I ain't gonna at that price!!!

[Drax240z]

A cut away view of a torsen:

 

 

3 washer packs, one on each end of the main splines, and 1 in the middle, seperating the 2 axle splines. Each end 'pack' has a needle bearing and a thrust washer, while the middle pack has a hardended bronze bushing and thrust washers. (barely visable between the 2 helical gears on top)

[JMortensen]

So where is the fuse???

 

Seriously, if I'm reading your description and looking at the picture right it sounds like the bearings have more to do with the side gears than the helical gears. The helical gears are what create the friction and limit the slip.

 

That is weird though, it's the first time I've seen side gears with a bearing under the thrust washer, and I'm still not sure what the function of the bushing in the center is.

 

Maybe the side gears move A LOT, and the bearing prevents them from binding and wearing into the case and the bushing prevents them from grinding on each other in the center???

[SleeperZ]

....what have I started?

 

I'll just stick to my 1WD for now. I guess leaving two marks isn't THAT important.

 

I know exactly how you feel. I've been seeing this debate unfold here for years, and I have still not made my own mind up as to which LSD I want. But look on the bright side: The IRS (independent rear suspension) on the Z car is a really good one. Lot's of people can make two marks on an open diff, and I've not found 1WD to be any handicap at all on the strip. Of course I'm only cutting 1.9 second 60' times, but it's fast enough for me presently.

[HS30-H]

I don't care if it's exchange rates' date=' or labor prices or what, if I have to pay 3 times the value of any part, I'm not likely to buy it. [/quote']

 

Its labour prices and exchange rates, and a whole lot of other things that makes them cost what they do. But now you are talking about "value", which is a subjective term.

You have decided what the "value" of the Quaife ATB is to you, and presumably 99% of early Z owners in the USA have decided that an LSD unit is not good enough "value" for them either. Maybe that's why you can't persuade the US manufacturers to knock up 500 or so units. They know they would not be able to sell them, perhaps?

 

That's where you and I disagree. I think that auto parts have a value that is not dictated by its country of manufacture, but rather by how good they are. So if there is no value gained I won't pay $50 for an Icelandic roll pin or $100 for a Siberian radiator cap, or $90 for a Ecuadorian ignition coil, or $1500 for a British LSD.

 

I understand exactly what you are saying, but I personally know how much it costs to make stuff like the Quaife ATB in my home country ( and south east England at that, where costs are even higher than other regions ). I'm not saying that expensive is automatically good, or exotic is 'cool'.

 

What you "value" it as is up to you, but what it costs to manufacture in real terms is what I'm talking about. If your US manufacturers would design and manufacture a unit, and accept re-makes for orders of 25pcs, then I'm sure you would not even be discussing the Quaife unit anyway.

 

I am glad that you know how to spell QUAIFE. Most people don't seem to be able to spell it, let alone know how their ATB actually works..............

[Drax240z]

That is weird though, it's the first time I've seen side gears with a bearing under the thrust washer, and I'm still not sure what the function of the bushing in the center is.

 

When turning the car, the two axles move at different speeds (obviously) and the axles are directly linked to each center gear via a spline. So the 2 gears need to move at different speeds, the bushing in the center allows minimal friction between these two side gears... With too much friction here you'd end up skittering like a locked diff would.

 

Also as best I can recall the side gears are free to move slightly, and would only constrained by the backlash on the helical gears (and the case itself) if not for the thrust bearings and washers.

 

So Jon you are saying the friction between case & helical gear is where the majority of the loading comes from... Fair enough, but I would think in that situation, the case would become a wear item. (it is hardened cast iron mind you) I can't see a lifetime guarentee given if the case (the main part of the Torsen diff) was a significant wear item. I know that if you want to replace the gears/bearings/shims in your torsen you can buy the parts off the shelf. If you want to replace the case, you need a new diff!

 

Due to the nature of helical gears though, there must be axial loading on those gears, and as a result there is likely friction between the end of the gears and the case.

 

Some more pics of the torsens I found on my HDD:

 

 

If you are wondering what I'd doing with the milling machine... well... don't ask.