Que es el QUAIFE?

[Raflekt]

Aqui checando el foro de serie 1 ya tienen quaife para el 135i automatico

Quisiera me apoyaran con sus conocimientos para saber mas de esa mod? para que es ? en que afecta o ayuda al coche?

Que tan recomendable es?

saludos

[KALEXO]

Es el diferencial de tracción, con este al ir saliendo de la curva te ayuda a mandar toda la potencia hacia la rueda de adentro, lo que te permite cerrar más la curva aterrizando la potencia del auto, es un upgrade sin duda de los mejores, pero tambien de los más caros, además de que hay que desmontar la caja para poderlo poner.

[Rodrigo Z.]

En realidad Quaife es una marca, no un diferencial.

Quaife entre otroas cosas fabrica diferenciales LSD (limited slip diferential). La idea de un diferencial de este estilo es que corrige una falla que han tenido los diferenciales desde que se inventaron. El diferencial se inventó para corregir el grave problema de hacer que un coche tuviera capacidad de poner potencia al piso en las curvas, ya que la llanta de afuera siempre gira más que la de adentro en una curva. Ese fue un gran problema hasta que apareció el invetor del diferencial (o engranaje planetario). El pex de ese invento es que por diseño manda la potencia a la rueda con menos tracción, entonces si te enllantas en cualquier situación, la llanta sin traccion se queda patinando y desaprovecha la tracción que puede tener la otra.

Un LSD por temas mecánicos de engranajes que se inventaron más recientemente que el tradicional tipo planetario (así lo fabrican Quaife y Peloquin, por ejemplo) mandan la potencia a la rueda que tiene más tracción. las ventajas son muchas, tanto en arranque brusco en recta, condiciones de grava, curvas al llevar al coche cerca del límite, lluvia, etc. También hay LSD's que funcionana a base de platos pequeños que funcionan como clutches y que pueden regular qué tanta tracción mantienen constnate en porcentaje entre la llanta izquierda y la derecha, hasta llegar a unos casi o completamente bloqueados comúnmente llamados "positraction" (usados más para cuarto de milla), pero que no están pensados para uso de ciudad porque arrastrarían una de las dos llantas en cada curva (es prácticamente como no tener un diferencial, sino una vil flecha bloqueda.

Es una maravilla de modificación, que en si debería ser parte de todos los coches de calle, el problema es que quien lo inventó lo patentó y las armadoras no gastan en esa patente más que para algunos coches (SRT-4 por ejemplo a partir del segundo año de fabricación).

Saludos.

[Rodrigo Z.]

Es el diferencial de tracción, con este al ir saliendo de la curva te ayuda a mandar toda la potencia hacia la rueda de adentro, lo que te permite cerrar más la curva aterrizando la potencia del auto, es un upgrade sin duda de los mejores, pero tambien de los más caros, además de que hay que desmontar la caja para poderlo poner.

En el caso de las curvas es al contrario Alexis, la potencia la mantiene en la llanta externa.

[Lucky Luciano]

En el caso de las curvas es al contrario Alexis, la potencia la mantiene en la llanta externa.

Mas bien yo diría que la potencia la manda a la llanta que tenga mas tracción independientemente cual sea si la externa o la interna.

[Raflekt]

Aqui la información que hay para el 135i , el pedo... el precio jajaja

http://www.1addicts.com/forums/showthread.php?t=20391&highlight=quaife

[Rodrigo Z.]

Mas bien yo diría que la potencia la manda a la llanta que tenga mas tracción independientemente cual sea si la externa o la interna.


Si no te topas con grava, aceite, etc, la física siempre carga más tracción a las llantas externas en curvas, aunque estoy de acuerdo contigo en que si se presenta algo fuera de lo normal (aceite por ejemplo) que haga perder tracción a la llanta externa al grado en que sea menor a la interna, pues si lo mandaría a la interna.

Saludos chiqui.

[Rodrigo Z.]

Aqui la información que hay para el 135i , el pedo... el precio jajaja

http://www.1addicts.com/forums/showthread.php?t=20391&highlight=quaife

Se ve muy bien el que sea específico para el coche, pero lo veo ridículamente caro. El aparato esperaría verlo en máx $1,500 usd.
Ahí vale la pena que tomes en cuenta el cambiar el paso del diferencial, para sacar más galleta al piso, aunque vas a tener un pilón menos de velocidad tope. Luciano hizo una investigación a fondo para los M3.

[Velvet]

yo digo que primero pongas lo mas importante, si no tienes buen manejo y dominas tu coche y no tienes tanta potencia el quaife o diferencial no lo vas a aprobechar

[luis_villarruel]

Esta es una vista interna de un diferenial Quaife para clio sport:

http://www.quaife.co.uk/shop_images/ATBdiff-cutout14549.jpg
http://www.quaife.co.uk/shop_images/QDF6M44674.jpg

es solo para que te des una idea,

saludos!

[MEXSYS]

Tengo una duda y no he encontrado exactamente la respuesta, ahi les va

cuando levantas un coche y quedan las llantas de tracción en el aire, por ejemplo un coche normal

Megane II giras una llanta y la otra gira al contrario, supongo que es un diferencial normalito o no ?

Cupra anterior, giras una llanta y la otra gira hacia el mismo lado, que tipo de diferencial es ? ( y no creo que traiga LSD de agencia )

en el ST giras una llanta y la otra no gira para nada. PERO lo raro es que siempre que patinas es con las 2 llantas, Jamás me ha tocado que solo lo haga una, incluso poniendo una llanta en agua y la otra en pavimento seco, patinan las 2. , en las curvas al acelerar fuerte te vas de frente porque empiezan a patinar las 2 llantas, Que diferencial es ?? ( tampoco es LSD ) será Autobloqueante ?

un LSD como se comporta cuando levantas el auto y giras una llanta, la otra que hace ?

Saludos

[Rodrigo Z.]

Tengo una duda y no he encontrado exactamente la respuesta, ahi les va

cuando levantas un coche y quedan las llantas de tracción en el aire, por ejemplo un coche normal

Megane II giras una llanta y la otra gira al contrario, supongo que es un diferencial normalito o no ?

Cupra anterior, giras una llanta y la otra gira hacia el mismo lado, que tipo de diferencial es ? ( y no creo que traiga LSD de agencia )

en el ST giras una llanta y la otra no gira para nada. PERO lo raro es que siempre que patinas es con las 2 llantas, Jamás me ha tocado que solo lo haga una, incluso poniendo una llanta en agua y la otra en pavimento seco, patinan las 2. , en las curvas al acelerar fuerte te vas de frente porque empiezan a patinar las 2 llantas, Que diferencial es ?? ( tampoco es LSD ) será Autobloqueante ?

un LSD como se comporta cuando levantas el auto y giras una llanta, la otra que hace ?

Saludos

Buena pregunta, nunca me he pueso a girar llantas con LSD levantados.

Lo único que te puedo decir es que como bien comentas, si giras una llanta y la otra gira en sentido contrario ES diferencial "tradicional" de planetario. CREEEO, que alguna vez platicando en taller me comentarion que con LSD mecánico (Quaife por ejemplo) las dos giran al mismo lado, pero el caso en que una gire y la otra se quede quieta no tengo idea. Puedo estar equivocado, insisto.

Saludos Oliver!

[Adrian_RT]

Buena pregunta, nunca me he pueso a girar llantas con LSD levantados.

Lo único que te puedo decir es que como bien comentas, si giras una llanta y la otra gira en sentido contrario ES diferencial "tradicional" de planetario. CREEEO, que alguna vez platicando en taller me comentarion que con LSD mecánico (Quaife por ejemplo) las dos giran al mismo lado, pero el caso en que una gire y la otra se quede quieta no tengo idea. Puedo estar equivocado, insisto.

Saludos Oliver!

Pues no aun con LSD las llantas giran en sentido opuesto.

[Rodrigo Z.]

Pues no aun con LSD las llantas giran en sentido opuesto.


Gracias por la info. Debes tener la razón, porque los SRT's traen Quaife y seguro ya lo checaste físicamente.

Lo que se me hace raro es entonces el por qué en algunas carreras en México checan con ese sistema las ruedas para verificar que algún coyote no meta LSD.

Qué diferencia has visto entre el LSD y el diferencial tradicional verificable sin mover el coche?

[ManuelGA]

La forma de comprobar que un Tsuru GSR, Sentra GSS o Lucino GSR tengan LSD, es levantandolo y girando una llanta, si gira hacia el mismo lado: trae LSD, si gira en sentido inverso, no lo trae.

Les fallo, no se si es viscous o mechanic, les pregunto.

[Rodrigo Z.]

La forma de comprobar que un Tsuru GSR, Sentra GSS o Lucino GSR tengan LSD, es levantandolo y girando una llanta, si gira hacia el mismo lado: trae LSD, si gira en sentido inverso, no lo trae.

Les fallo, no se si es viscous o mechanic, les pregunto.


Lo mismo sabía yo, pero ya ves que Adrián da a entender que en su SRT no.

( a menos que lo hayan chamaqueado y le hayan vendido su SRT sin Quaife, je).

[ManuelGA]

Lo mismo sabía yo, pero ya ves que Adrián da a entender que en su SRT no.

( a menos que lo hayan chamaqueado y le hayan vendido su SRT sin Quaife, je).

Pudiera ser que el efecto del Quaife sea diferente en estado estatico al de LSD mas tradicionales, digo, recordando que el de estos Nissanes viene de principios de los 90's?

[Bytemax]

pues por lo que leo hay 3 diferentes, el abierto, el bloqueado y el de derrape limitado.. ahi se los dejo...

http://www.houseofthud.com/differential.gif


The Open Differential

Open Differential diagram

That's more or less the diagram of the inside of differential for a rear wheel drive car. A front wheel drive car basically doesn't have a normal "Input Shaft", but everything else is the same. I simplified it greatly as there may be more than 2 spider gears and I didn't show the bearings where the output shafts go through the housing. A real differential is also very compact with all the gears nearly the same size and packed together. Additionally, all perpendicular gear intersections use beveled gears (cut at an angle) but that was too hard to draw. See this diagram of a center differential. (The part of the left is the differential.. part on right is a Viscous Coupling)

Anyway, I'll explain and you can look at the diagram. (Click on the image to open in a new window)

The left and right drive gears have teeth on their sides. They are attached directly to the end of the left and right output shafts, and turn freely on bearings in the ends of what I called the Outside Housing.

The thing labeled "Outside Ring Gear" is a ring gear attached directly to the housing which takes power from the input shaft which comes from the transmission (directly off the tranny's output shaft/s for a FWD car or via drive shaft for RWD). When the input shaft turns, the ring gear turns and the entire differential housing turns. But I'm getting ahead of myself. Let's see what the differential does all by itself.
Example 1:
So you're holding this thing in your hand by the outside housing. If you grab the right side output shaft and turn it, it'll turn the right drive gear. The drive gear will spin the spider gears, the spider gears will turn the left drive gear and the left output shaft on the opposite side spins in the reverse direction.

That is the "open" part of an open differential.

So how is power applied?

Example 2:
When torque is applied to the input shaft, it turns the entire housing as I've said. The housing is attached to the axles of the spider gears. I have to repeat that. It's attached to the axles of the spider gears, so it's pushing the spider gears sideways such that the spider gears are forced to move around and around (actually end over end.. whatever makes sense to visualize). If the resistance on both output shafts is the same, then the spider gears do *not* themselves rotate as they did above. They simply remain fixed to the side of the housing, and push equally on the teeth of both drive gears, and both drive gears turn at the same speed.

Example 3:
Ok, now grab the right output shaft and hold it fixed. Continue to rotate the input shaft. The outside housing continues to rotate at the same speed, as it did for Example 2. However, now the spider gears can't make both output shafts turn at the same speed (as one is being held stopped). Here's where you need a hands on demo of what happens.
Wacky Demo 1: Grab a computer or audio CD. Stick your finger through the hole in the middle and roll it slowly across a table or desk. While you're doing that let the fingers on your other hand rest gently on the top edge of the disc, and move with it. The disc represents the spider gear. Your finger is the axle attached to the housing moving at a fixed speed. The table represents the non-moving right side drive gear, and your other hand is the left side drive gear. Note that as you roll the disc at a constant speed X, the top edge of the disc is moving forward at speed 2X.

That's what happens inside the differential too. If you hold one side fixed, and continue to apply torque, the other side of the differential rotates at twice the speed it normally would (twice the speed of the ring gear and housing).

When you're driving around a turn, this all works together. The inside tire must turn slower than the outside. With constant throttle the housing speed remains fixed, but the spider gears rotate very slowly which allows the wheel on the inside of the turn to rotate a little slower than it normally would and the wheel on the outside of the turn to rotate faster than it normally would. The housing rotational speed is always the average of the two sides. Great for going around turns at slow speeds.

So what's wrong with the open diff?

The problem is an open diff always tries to balance the torque. That's a hard statement to get a grasp on, but it means that if the spider gears are pushing on both drive gears and one of them offers lots of resistance (tire sitting on pavement) and the other side offers no resistance (up in the air, or sitting on a patch of ice), then it will find a happy balance where both sides are receiving almost no torque at all. All the rotational energy is guided to the side with the least resistance. In the end, that side spins very fast and the pressure on each drive gear is the same.. Almost no torque is needed to spin one wheel, and since the open diff always sends the same amount of torque to both output shafts, almost no torque is going to the other side as well. Anyone who's driven on snow or ice knows this trick.

So.. Back to the original question. What's a limited slip diff?

Let's start with the opposite of the open diff first.
The Locking Differential:

Go back to the diagram. Look at the spot where the line from the label "Right Drive Gear" touches the drive gear.
Drill a hole there all the way through it, and through the left drive gear on the other side. Stick a steel pin through the holes. Now both sides of the differential are locked together. This is a simplified "locking differential". The housing turns, the spider gear pushes on both drive gears, and no matter what the traction situation is, they are forced to turn at the same speed. Real locking diffs use a pneumatically or hydraulically activated sleeve that slides across between the drive gears out near their edge to lock the drive gears or spider gears in place, but the effect is the same. This is great when you have no traction on one side, because no matter what, both sides turn at the same speed, and if one side offers lots of resistance, and the other none, then effectively all the "usable" or "useful" torque goes to the side where there is resistance. It's getting 100% of the available torque. The side with no traction doesn't need torque to spin helplessly, so it's not really getting 50% of the torque as you might think, but closer to zero %.

[Bytemax]

aqui la continuacion.....


Problem with a locking diff, is of course why we don't all just have solid axles. When you go to drive around a corner, both tires are forced to turn the same speed. Because the path of each tire is of a different length, either one drags while the other spins a little, or probably the outside matches the ground speed (as the weight transfers outward) and the inside tire spins on the pavement (shorter distance to travel, but it's spinning as fast as the outside tire which has farther to go in the same time). Either way it tends to make the vehicle want to go straight all the time, and puts a lot of stress on the drivetrain..
Limited slip differentials.

A limited slip differential is a compromise. We'd like a full locking diff in specific instances of extreme traction imbalance but otherwise would prefer operation closer to an open diff, so that the tires can turn at different speeds around corners.

Disclaimer: I'm making up some of the implementation details below to illustrate a concept. The real construction details of these devices are most certainly different. My intent is to allow you to visualize how a limited slip diff differs from an open or locking diff. Some of the designs I've heard, of but don't know where or if it's been implemented. See the AWD page for more detailed information.

Viscous Coupling: (Syncro)
Go back to the diagram and put some intermeshing fins in the space between, and attached to, the drive gears. Make the fins all move close to each other, but let them pass without touching so both drive gears can still rotate at different speeds. Now enclose the space around the fins and fill it all up with a thick fluid. Now as long as both sides are turning the same speed the fins also move at the same speed, and the difference between their speeds is zero. But go back to Example 3 where one side is held still. As you rotate the housing at speed X, the difference in speed between left and right sides is 2X. That's enough to get the fins all moving past each other through the oil and the fins of one side impart some energy to those on the other side via the liquid, which typically is designed to heat up and become more viscous in this situation.. Now some percentage of torque is transferred to the right side that you're trying to hold still.

This is a speed sensitive limited slip. If you turn it very slowly very little torque is transferred to the fixed side. As the input speed increases, it becomes harder and harder to hold the right output shaft still. As the speed difference increases, so does the torque transferred. Eventually enough torque will transfer through the viscous coupling to get your car out of whatever predicament it's in.

The downside is that you're constantly turning all these fins and liquid and if you're driving around tight corners a lot, it is transferring torque across to the other side, perhaps when it doesn't need it. You may still get some wheelspin on the tire on the inside of a turn, for instance. Also, you may find, after getting stuck that the side that's spinning ends up spinning so much that the tire digs a hole in the ground out of which you can't climb, even when torque is transferred over to the side with traction. A VC diff is rarely used at the front or rear axles.

The VC is most often used as, or part of, the center differential in an AWD system. The VW Syncro system was originally developed by Audi and then discarded in favor of a torsen diff, but VW incorporated the viscous coupling into their Syncro AWD system. That has since been replaced by the 4motion system. Some AWD systems simply put a VC in the center of the car and nothing else. When the VC is tied to a differential, then the power is normally split between front and rear axles equally. Without the differential, and only using the VC, power normally goes to only one end of the car and the other end just floats along with the VC absorbing any speed differences. If it's normally a front wheel drive car, and the front wheels start to spin, then the pure VC starts transferring torque to the rear wheels. Others, like Porsche and Lamborghini, have done it the other way around, transferring torque to the front only when the rear tires slip. You'll see these described with something like a 90/10 torque split because they design them to always slip a little bit even when driving straight, to keep the viscous fluid warm, so that the VC will activate quicker.

One big problem is that VC interferes with the operation of the ABS brakes. The VC keeps the wheel speeds linked together, while the ABS may need to brake one side (or end) of the car harder than the other. The VC may cause a tire to lock and slide while the ABS is trying to prevent it from sliding. Most VC AWD systems have some sort of disengage mechanism that takes the VC out of commission as soon as you step on the brakes.
Clutches (Passive, Hydraulic, and Electronic):
Most of the more popular LSD systems fall into this category. I'll just get this out of the way up front. The biggest problem with all clutch systems is that they wear out over time, but it can be a very long time. And like all clutches they generally have a fixed upper limit on their torque carrying capacity.

Anyway, how do we get rid of all those fins, liquid, and weight from the VC?
Passive Clutch:
Let's try a passive clutch. To the back of one drive gear is attached a set of metal clutch plates, and to the outside housing are clutch pads. Back this clutch pack with heavy springs that squeeze the plates between the clutch pads and so on. Again, nothing happens in normal conditions with equal traction, as both drive gears turn at the same speed. When one side loses traction and the diff tries to spin that side, the spring loaded clutch simply imparts a fixed amount of torque back to the other side. With a passive clutch, it doesn't get better with speed either. If anything it transfers less torque at higher differential speeds, (dynamic versus static friction). You might be tempted to add bigger springs to make the clutch engage harder but then you'll end up with some of the same bad traits of a locking diff under low traction conditions when just driving around corners at normal speeds when one side will drag and the other spin.

Progressive/Locking Clutch (Positraction or Salisbury type):
This is probably the most common type of LSD. Here there are a set of clutch plates attached to the inside of the housing just outside of each drive gear, and a set of clutch disks attached to the output shafts, but also still inside the housing. There are two thick pressure rings which attach to the inside of the housing near the spider gear shafts. The pressure rings push outwards against the clutch packs. The space between the pressure rings forms an opening that is wedge shaped, and the spider gear shafts themselves, form the wedge. As power is applied to the ring gear, and transmitted to the housing, and down into the pressure rings, they start to push on the spider gear shaft which (depending on traction conditions) wedges itself toward the end of the opening between pressure rings, which forces the rings away from each other, which applies pressure to the clutch packs, which locks both drive gears to the outside housing and under very high power the differential locks up nearly solid.

So this one is power sensitive. Note, there must also be some preload built in, for use in low traction conditions. This system relies on there being some resistance to the applied power to cause the pinion gear (spider gear) shaft to wedge open the pressure rings. If you started with no static clutch pressure, then under very low traction conditions (one side on ice), there won't be enough resistance to wedge the pinion shaft in place and it'll remain an open diff. As a result there's usually enough static load added to provide some constant torque split to both sides, and then if you hit the gas, it'll lock up the diff and you get torque down to whichever side can use it. I gleaned much of this information from a Semi Technical Discussion of an LSD made for Datsun/Nissan trucks. This type of LSD is popular in the 4x4 community as a compromise between open and full locking, but full locking (air lockers) are still preferred for serious wheeling. Drag racers also use this type, because it locks up under high power and keeps the car pointed pretty straight.

Simple Hydraulic Clutch:
Put the same clutch pack in, but put a hydraulic actuator behind it instead of the springs. Now, pumping oil into the innards of a rotating mechanism is possible (and I'm sure has been done) but is hard so instead it's often done in a clever fashion. You attach a small hydraulic pump to one or more of the spider gears, or a floating gear that spins at the same speed as the spiders but without carrying the load. The pumps simply scavenge the oil from wherever they can inside the case and pump it into the actuators behind the clutch. Remember the spider gears only rotate when the drive gears are rotating at different speeds. As you can guess, this system is also speed sensitive as the hydraulic pump only works when one side is spinning faster than the other, but the hydraulics offer much quicker activation than the viscous coupling from above, and the clutch pressure can be maintained with less speed differential. We may still have the clutch wear problem. Also the activation rate is basically fixed by the designers.

Electronic Clutch (or electronically activated hydraulic clutch):
Getting electricity into the center of the diff isn't much easier than getting hydraulic fluid in, but it's possible. So electronic actuators may put inside to either directly drive the clutch, or to run an electric hydraulic pump, or simply to regulate the rate of the hydraulic pump in the previous system. Alternately, it usually just uses a electronically activated hydraulic pump outside the housing but inside the transaxle (or differential case) that pumps oil to a hydraulic actuator that pushes against a sliding ring around one or both of the output shafts which ultimately reaches through holes into the clutch pack. In this configuration one can apply a large amount of pressure to the clutch pack inside the diff. The nice thing about this system is that it's infinitely tunable. You can lock the clutch up at any speed to transfer from 0% to 100% of the torque to the side that can use it most. The VW 4motion system (based on Haldex coupling) uses electronically activated hydraulic bypass valves, and can be tuned via software to send from 0 to 100% of the input torque to the output shaft on the fly. . Basically it's a simple hydraulic system as above, but the pressure can be regulated via electronically controlled valves. The old Mercedes 4matic system used electronically activated hydraulic clutches first at the center diff, and then later at the rear diff dependent on wheel speed measurements taken from the ABS wheel speed sensors.



I

[Bytemax]

y por ultimo....

These systems are often fairly complex as they require a computer to keep track of it all, and they must usually apply pressure to the clutch pack in the differential via sliding bearings. Those bearings are at risk of increased wear along with the normal clutch wear. The most complex system ever developed was that on the Porsche 959 which didn't even wait for wheel slip before transferring torque. It monitored everything.. steering angle, lateral acceleration, throttle position, yaw rate, and wheel spin, to constantly shift the torque where required. The ultimate goal was to cure the rear engine RWD tendency to lift throttle overseer that the 911 suffered until 1993. (They eventually fixed the overseer problem with simply a new rear suspension and fatter rear tires.)

EDL (often referred to as Electronic Traction Control.)
This system is used by most VW models today, many Audis and several other car models, and was first introduced for offroad use in the Mercedes ML320 (AWD) and is undoubtably used by many others today.
It's what I call the poor man's LSD. (Some people dislike my characterization of it, as it can be very finely tuned, but it's still very cheap to implement and has some reliability and torque handling problems.)
This is an electronically regulated speed sensitive system using the two independent ABS channels. Start with an open differential and go back to Example 3. You're holding onto the right output shaft while the input shaft turns. Now add a disc brake and rotor on the left input shaft.
Activate EDL system. When the computer senses a speed imbalance between left and right, (remember the left shaft is spinning at 2X and the right is not moving at all), it simply applies the brakes to the left side output shaft. The open differential immediately tries to balance the torque. You will feel it trying to turn the right side immediately. If it can grab the left harder than you're holding the right (which it most certainly can and will) then it would immediately transfer some rotation to the right output shaft and it will twist out of your hand. If you could hold onto the right side hard enough (weld it the side of a tractor trailer truck) , it would be forced to slip the left brake disc, or stall the engine.

In practice, the engine will not stall because the maximum resistance is simply whatever it takes to move the mass of the car, or spin the other tire. So if one side is spinning and the other side has traction, then the EDL will brake the spinning side, and the torque transfers to the side with greater traction and either that side spins or the car moves.

Now, all my examples have been pretty extreme. The EDL doesn't actually stop anything. It simply slows it down until the speed difference is equalized, and it does this by pulsing the ABS channels maybe a dozen times a second. It switches off when the speed differential is low enough.

Also note, it does not try to prevent wheelspin! If both sides lose traction at the same time and spin at the same speed then EDL has no idea anything is wrong. A more advanced system measures the difference between the speeds of all 4 wheels during acceleration and assumes that anything spinning faster than the slowest rotating wheel is slipping (often referred to as ASL today). A cheap system will apply the brakes. An expensive system will reduce the throttle until the problem goes away. BMWs and new VWs use this method to prevent wheelspin.

The problem with the way EDL works is that it's pretty harsh. The pulsing of the ABS isn't progressive. If the ABS is on, it applies full braking power followed by zero braking power.. full, zero, full, zero.. The torque from the engine that's being transferred repeatedly all the way across the drivetrain from wheel to wheel a dozen times a second, puts stress on everything. Brakes, rotors, axles, U joints, output shafts, and the differential itself. The left and right halves of the differential in the VW 02A transmission are held together with rivets which if forced to take this pounding too long will eventually fail. Neat huh?
Did I mention EDL uses the brakes? Perhaps "uses up the brakes" would be more appropriate. It's really designed for emergency low traction situations and not drag racing or rallying or other long duration, low traction situations. Most EDL systems today only operate at speeds under 20mph.

So why use EDL if it's so bad?
Well, the torque transfer is only really bad if the input torque is high and the resistance at the side where it's being transferred to is high. Such as.. When you're spinning one tire on the pavement and the engine is cranking out maximum torque, which is then multiplied by the tranny's gear ratios, but an order of magnitude. When it kicks that torque across from one side to the other, it finds that the other side (also on pavement) initially has lots of traction and therefore a lot of resistance which means that the drivetrain takes the brunt of the stress all at once. Worse case, is when the side that is slowed, slows enough to regain full traction, while the other side starts spinning. Then the EDL compensates and brakes that side.. and the whole process repeats back and forth many times.. Only reasonable solution.. take your foot off the gas.
On the other hand, if one tire is on snow, and the other is spinning on ice and the EDL has you accelerating slowly, the engine is producing little torque and if you tried to gas it hard, the torque transfer from the EDL meets with little resistance on the snow so the torque "escapes" as wheelspin on the snow side. If it's ice and pavement then yes, you want to avoid mashing on the gas, but pulling away smoothly shouldn't present a problem as each pulse of the ABS transfers into a small bit more acceleration of the car.

Should I worry when the EDL kicks in?. The ABS and diff can't transfer any more torque through the drivetrain than the engine supplies and the best case traction resistance allows. If traction is low on both sides, and power is high the traction is the limiting factor to how much drivetrain stress is induced. Otherwise, if one side had good traction on only one side, then just don't hammer the gas. If you're spinning the tires on dry pavement, expect TFS. Simple.

Quattro, Quaife, Torsen, Peloquin: (Torque Biasing Differentials)
Audi's Quattro (Audi's marketting name for all their AWD systems) using Torsen and the popular aftermarket Quaife systems use a set of worm gears inside the differential in place of the simple bevelled spider gears, which bind up when there's a resistive torque imbalance. That means, as long as both sides show equal resistance then they are free to rotate at different speeds, such as when going around a turn.

The whole thing is often called a "Torsen" system as in "Torque Sensing" (Torsen is actually a registered trademark, and the more generic term is Torque Biasing Differential or TBD) because it instantly reacts to torque imbalance transferring torque to the wheels that can use it most. There's a difference between the two main types of torque biasing diffs. Quattro's Torsen diffs used something developed by Gleason called invex gearing which is is really all about worm gears. A torque imbalance causes it to *try* to turn the low traction output shaft faster than the higher traction side, but that would cause the invex spider gears to turn, and they drive worm gears which have a greater mechanical advantage (due to the angle of the teeth) than the output sun gears have on the worm gears. That means that a multiple of the torque that would have gone to the low traction side actually goes to the high traction side. So if 20 ft-lbs of traction is at the low traction side, something like 80 ft-lbs goes to the side that can actually use it. A ratio of 4 to 1 or 5 to 1 is common but changing the gear teeth angles changes the ratio. The Quaife unit uses helical gears to accomplish very much the same thing, but the actual operation is not nearly as easy to understand. The helical gears float in pockets on the inside of the housing and apply radial and axial forces generated by the angle of the gear teeth. It can be tuned just like the invex gears to vary the torque ratio. Note however that without significant preload either torque biasing diff will not work well with a wheel completely off the ground. 0 ft-lbs time 4 is still 0. A simple braking trick helps though. (Note, the EDL system discussed above, actually works pretty well with a torsen diff. It activates rarely, but allows for much greater torque transfer when it does.) For this reason, they're rarely found on offroad 4x4 vehicles, the notable exception being the original Hummer H1, which has a note in the owner's manual explaining how to use the brakes and gas at the same time, should one or more tires be off the ground (as is not uncommon while offroading).
t is capable of going from an open differential to say 60% locked differential condition absolutely instantly (zero lag), so many would argue that it's about as close to perfect as it gets for performance driving. There are no clutches to wear out. Several AWD systems like the Audi Quattro system put a torsen diff in the center of the car to control slip between front and rear wheels. This system does not have the problem the VC does with the ABS. A torsen diff only distributes torque when it's under load. When it's freewheeling all the wheels can turn at different speeds as the ABS may desire.
(Note: The current Audi Quattro system only uses the torsen diff in the center, and some other LSD or just EDL at the axles. )

The disadvantages are that the mechanism is a bit heavier (in rotating mass, where it counts more), more mechanically complicated than some, is expensive, and can't be tuned or adjusted dynamically. Plus, it reacts so fast and is so even handed that it literally makes a torque biasing diff equipped AWD car a little boring when you'd really like to hang it all out. If you want to go 100mph in the snow nothing beats Quattro. A system that'll let you change the torque bias between front and rear dynamically will usually be more fun though.

BTW, I do think that a Torque Biasing Differential in a front wheel drive car is a good thing. If you plan on putting a blower on your engine, get a Torque Biasing Diff . . If you worry about EDL hammering and TFS a lot, get a torque biasing diff. It'll help you put down power on a twisty road, and reduces torque steer. I finally bought a TBD from the machinist Gary Peloquin (mechanically similar to the Quaife) that made my FWD GTI VR6 a joy to drive fast around sharp corners while full on the throttle, which is not normally fun in a higher powered FWD car.

[GOU]

jajaja che rafa.. y me dices "caliente" a mi :risas

Yo le puse el quaife lsd a mi civic..... y si se nota mucho el cambio, pero mas q nada fue por q traigo otro motor y un desmother en mods...

yo creo q ya meterse en el 135 con un quaife.. pues mmm :fight, que digo ahi en el foro ya 2 q 3 se lo metieron y dicen q muy bn.... pero asi stock esta bien yo creo...

primero lo basico:

1.- INTAKE
2.- REPRO
3.- B.O.V
4.- DOWNPIPES
5.- CATBACK
6.- COIL OVERS
7.- F.M.I.C

etc....-

[CARO]

muy buena info, as always......

[Raflekt]

Goü en cuanto los filtros?

Un saludo

[Lucky Luciano]

Con el Quaife en el jetta, las llantas jalaban las dos en el mismo sentido con el coche levantado, en el evo, giran las 4 llantas en el mismo sentido 100% seguro.

Si en el cupra jalan en el mismo sentido seguro que tiene algun tipo de bloqueo en el diferencial mecánico, si en el st una gira y otra no pero patinan las dos juntas, seguramente el bloqueo es electrónico mediante la bomba del abs y el control electrónico de tracción.

[vand]

Se ve muy bien el que sea específico para el coche, pero lo veo ridículamente caro. El aparato esperaría verlo en máx $1,500 usd.
Ahí vale la pena que tomes en cuenta el cambiar el paso del diferencial, para sacar más galleta al piso, aunque vas a tener un pilón menos de velocidad tope. Luciano hizo una investigación a fondo para los M3.

+1, esta carisimo.

BMW asegura que el dif electronico del 135 (fabricados despues de Mar-08) hace el mismo trabajo que un mecanico sin el contra del peso y arrastre extra. Me parece que ya tambien traen este dif los nuevos serie 3 y serie 7. En lo personal estoy un poco esceptico en esto, no creo que mande al piso las llantas como un mecánico, pero pues ahi lo trae y debe hacer un buen trabajo.

Si le pones LSD a un coche que no trae nada la diferencia es bastante grande, pero al 135 que ya trae el dif electronico la diferencia es menor (o ninguna segun BMW :bla ) y para mi no vale ese precio.

[Raflekt]

GRACIAS a todos por sus aportaciones ya aprendi mas o menos para que sirve ypor el momento esta muy caro para lo que le tengo planeado al coche,

ahorita ya le estoy comprando su oil cooler kit , sus valvulas y el chip , ya que del rio no me atendio bien jaja ardido


saludos

[Lucky Luciano]

+1, esta carisimo.

BMW asegura que el dif electronico del 135 (fabricados despues de Mar-08) hace el mismo trabajo que un mecanico sin el contra del peso y arrastre extra. Me parece que ya tambien traen este dif los nuevos serie 3 y serie 7. En lo personal estoy un poco esceptico en esto, no creo que mande al piso las llantas como un mecánico, pero pues ahi lo trae y debe hacer un buen trabajo.

Si le pones LSD a un coche que no trae nada la diferencia es bastante grande, pero al 135 que ya trae el dif electronico la diferencia es menor (o ninguna segun BMW :bla ) y para mi no vale ese precio.

Los diferenciales electrónicos sirven mejor que no traer nada y para uso cotidiano estan bien, pero no se compara a unos diferenciales mecánicos, estilo el que usan los m3.

Y pues si son caros definitivamente y tienen desventajas en cuanto a peso y a pérdida de potencia, pero también beneficios en cuanto a mejor desempeño del coche.

[MEXSYS]

Los diferenciales electrónicos sirven mejor que no traer nada y para uso cotidiano estan bien, pero no se compara a unos diferenciales mecánicos, estilo el que usan los m3.

Y pues si son caros definitivamente y tienen desventajas en cuanto a peso y a pérdida de potencia, pero también beneficios en cuanto a mejor desempeño del coche.

ok, entonces haber si entendí

el ST es posible que tenga algun bloqueo electrónico para que cuando envías cierto torque o aceleración en las ruedas las 2 aceleren iguales, esto supongo que es muy bueno para arrancar. es mejor que no traer nada, pero en una curva por ejemplo, si acelero en cualquier curva el coche por traer tanto torque en baja se va de frente al patinar las 2 llantas al mismo tiempo estas pierden traccion y bye bye.
Un coche que trae un diferencial Abierto que digamos trae buena potencia aceleras en curva y empezara a patinar como loca la llanta de adentro porque va casi volando, pero como la llanta de afuera no patina esto ayuda a que no te vayas de frente, pero esto hace muy lento el coche en una curva, estoy bien ??

creo que si es mejor traer el bloqueo electrónico ya que puedes modular el acelerador y salir más rapido que con un auto con diferencial 100% abierto.

un diferencial LSD supongo que puedes acelerar mucho mejor en una curva ya que al entrar a una curva la potencia la manda al contrario de un abierto, a la llanta de afuera ( la que trae mas tracción ) y a la llanta de adentro solo manda lo minimo para que no patine y al no patinar no pierdes tracción y no te vas hacia afuera . me imagio que practicamente te clava la dirección el carro al acelerar en una curva. al contrario de un coche normal que te vas de frente o empieza a patinar y no acelera nada de nada.

esto es correcto ?

saludos

[Pantoche]

Ya que están hablando de diferenciales, porque me dijeron en la agencia que se "daña" el diferencial del carro en caso de que lo suban a los rodillos del verificentro??
Al detectar que no giran las llantas de atras manda la tracción para atrás y daña el coche o como esta eso??
Según tengo entendido los dos diferenciales son LSD....

[evadillo]

Ya que están hablando de diferenciales, porque me dijeron en la agencia que se "daña" el diferencial del carro en caso de que lo suban a los rodillos del verificentro??
Al detectar que no giran las llantas de atras manda la tracción para atrás y daña el coche o como esta eso??
Según tengo entendido los dos diferenciales son LSD....

Ningun tracción integral puede meterse a rodillos para dos ruedas.. desde el sistemas electronicos hasta mecanicos... no se si se lleguen a dañarse (que es lo mas logico)... pero mas bien no podrian permancer staticos durante la prueba a menos que los subieran a estanquillos en la parte trasera o delantera !!!

[Rodrigo Z.]

ok, entonces haber si entendí

el ST es posible que tenga algun bloqueo electrónico para que cuando envías cierto torque o aceleración en las ruedas las 2 aceleren iguales, esto supongo que es muy bueno para arrancar. es mejor que no traer nada, pero en una curva por ejemplo, si acelero en cualquier curva el coche por traer tanto torque en baja se va de frente al patinar las 2 llantas al mismo tiempo estas pierden traccion y bye bye.
Un coche que trae un diferencial Abierto que digamos trae buena potencia aceleras en curva y empezara a patinar como loca la llanta de adentro porque va casi volando, pero como la llanta de afuera no patina esto ayuda a que no te vayas de frente, pero esto hace muy lento el coche en una curva, estoy bien ??

creo que si es mejor traer el bloqueo electrónico ya que puedes modular el acelerador y salir más rapido que con un auto con diferencial 100% abierto.

un diferencial LSD supongo que puedes acelerar mucho mejor en una curva ya que al entrar a una curva la potencia la manda al contrario de un abierto, a la llanta de afuera ( la que trae mas tracción ) y a la llanta de adentro solo manda lo minimo para que no patine y al no patinar no pierdes tracción y no te vas hacia afuera . me imagio que practicamente te clava la dirección el carro al acelerar en una curva. al contrario de un coche normal que te vas de frente o empieza a patinar y no acelera nada de nada.

esto es correcto ?

saludos

Así es, con LSD sientes que al acelerar en curva (en un tracción delantera) el coche se mete a la curva.

[Raflekt]

Y en un trasera? Awd?

Saludos

[lordvader]

Ni hablar un Quaife es lo indicado para aplicaciones de performance en tracciones delanteras especificamente.

[Rodrigo Z.]

Y en un trasera? Awd?

Saludos

En un tracción trasera te permite, al igual que en el tracción delantera, acelerar un pilón de más a la salida de cada curva (obviamente sin perder la tracción de las ruedas).

[Raflekt]

Actualización

Quaife ATB Limited Slip Differential for 135i

--------------------------------------------------------------------------------

Quaife, The Ultimate Differential is now in stock for your 335i at HP Autowerks, Inc.


"The Quaife Automatic Torque Biasing Helical LSD Differential enables a car to accelerate more rapidly and corner faster. How?

Simply by getting the power to the ground!

With an normal open differential, fitted as standard on most cars, much precious power is wasted through wheel spin under acceleration. This happens because the open differential shifts power to the wheel with less grip - along the path of least resistance.

The Quaife differential, however, does just the opposite. It senses which wheel has the better grip, and automatically biases the power to that wheel. It does this smoothly and constantly, and without ever completely removing power from the other wheel.

In cornering, while accelerating out of a turn, the unit biases greater 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 differential also controls loss of traction when the drive wheels are on slippery surfaces such as ice and snow or mud, providing the appropriate biased traction needed to overcome these adverse conditions. Power is transferred automatically without the use of normal friction pads or plates seen in other limited-slip designs.

The Quaife ATB Helical LSD differential'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 differential is extremely strong and durable, and since it is gear-operated, it has no plates or clutches that can wear out and need costly and regular replacement. There is no maintenance required to the unit, so you can fit and forget.

The Quaife differential 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 cars towards its limits.

The Quaife differential is proven in everything from SCCA Rallying to drag racing and Formula 1. It provides autocrossers with such an advantage, it has become "required" equipment for a winning effort.

Expand your vehicle's limits with the Quaife ATB Helical LSD Differential!"

Here is a video on Quaife LSD:

http://video.aol.com/video-detail/bm...tial/538903604

Top tuners using our Quaife LSD:

Berk Technolgy's Redline Time Attack 135i

Burger Motorsport world's quickest 135i
Vishnu Tuning

Most of the automatic transmission 135i come with a bolted diff, so all you need is the Quaife and a local shop capable of the install.

For manual 135i's with a welded differential: We can offer a complete Quaife Final Drive Unit for a direct swap.

Price is $1450 plus freight.
----------


como veran ya bajo de precio , creo q tengo q ahorrar

[splub]

Algo sobre diferenciales. recuerden que son muy usados en los 4x4. Y que los hay de una o dos vias, aceleracion y desaceleracion. Los torsen, Haldex, elecrtonicos Y mas.

diferencial. Es un mecanismo que permite transmitir fuerza de giro, al unísono, a dos ejes que no giran solidarios. En un automóvil, los diferenciales cumplen una misión fundamental: compensar la diferencia de distancia que recorren las ruedas exteriores frente a las interiores al tomar una curva. El eje que mueve cada una de las ruedas, va unido a un piñón denominado planetario. La fuerza del motor llega al engranaje principal de la corona del diferencial, que a su vez cuenta con unos piñones libres denominados satélites. En línea recta, los satélites empujan a los planetarios, pero en curva además giran sobre sí mismos, absorbiendo la diferencia de giro de los semiejes. El problema del diferencial convencional es que cada semieje sirve de apoyo para que el otro haga fuerza (acción-reacción), por lo que en caso de pérdida de adherencia de una rueda, toda la fuerza del motor se escapa por ella sin que el otro semieje pueda hacer nada. Este problema se soluciona con los mecanismos de control de tracción y con los diferenciales autoblocantes.

diferencial autoblocante. Es un tipo de diferencial bloqueable en el que sólo se anula una parte del efecto diferencial, es decir, limitan la posibilidad de que una rueda gire libre respecto a la otra según un tarado fijo predeterminado. Ese tarado se expresa como una relación entre las dos ruedas en tanto por ciento, de forma que el cero corresponde a un diferencial libre, y el 100 a ruedas que giran solidarias, es decir, con el diferencial completamente bloqueado (como un eje rígido). Los hay de varios tipos, aunque tradicionalmente los más utilizados eran los autoblocantes mecánicos, en los que al detectar diferencia de giro entre los semiejes la resistencia de un muelle hace actuar un mecanismo que aumenta el rozamiento interno limitando el efecto diferencial. En la actualidad se utilizan mucho los diferenciales autoblocantes electrónicos, que utilizan los sensores del ABS y frenan las ruedas que pierden adherencia (e incluso limitan momentáneamente la potencia del motor) para que no se pierda la capacidad de tracción por ellas. Otros tipos de diferenciales autoblocantes son los Torsen y los de acoplamiento viscoso.

Diferencial bloqueable. Se utilizan para evitar que la capacidad de transmitir movimiento de un conjunto mecánico se malogre porque una rueda patina. Pueden ser bloqueables manualmente o autoblocantes. En el primer caso, el conductor puede, a través de un mando específico, hacer solidarias las ruedas de un mismo eje, anulando el efecto diferencial. Al hacer solidarios los dos ejes, sólo se puede utilizar el bloqueo manual a bajas velocidades y cuando las condiciones de adherencia sean realmente malas, pues de no ser así la transmisión se vería sometida a esfuerzos que podrían producir daños mecánicos (En una curva cerrada el eje se retorcería excesivamente). Este tipo de diferenciales ya casi no se usa en turismos, y sólo se monta en algunos vehículos para todo terreno.

Diferencial viscoso. Es aquel en el que no existe una unión mecánica entre los semiejes, sino a través de un fluido de alta viscosidad. Este fluido baña un cilindro en el que hay dos juegos de discos intercalados, cada uno de ellos solidario con uno de los semiejes del diferencial. Si la diferencia de giro entre estos dos juegos de discos no es grande —por ejemplo, la que se produce entre las ruedas de cada lado al tomar una curva— se mueven casi independientemente. Ahora bien, a medida que la diferencia de giro aumenta, los que giran más rápido tienden a arrastrar a los otros. Si se trata de un diferencial trasero —por ejemplo— y una de las dos ruedas patinan, arrastra en alguna medida a la otra, lo que mejora la tracción. Este sistema puede estar unido a un diferencial normal, como sistema autoblocante; en este caso se denomina «acoplamiento viscoso». El principal inconveniente del sistema viscoso de transmisión es que su funcionamiento está muy condicionado por la temperatura del fluido, que pierde viscosidad a medida que se calienta.