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Sisteme AWD, care e cel mai bun?

This topic is about Sisteme AWD, care e cel mai bun?, the author, f1anatic, wrote about: Originally Posted by RobY There are many types of Subaru AWD systems the most advanced being the 5eat and the STI DCCD which are offshoots of the WRC ... To read more just scroll down

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> Sisteme AWD, care e cel mai bun?
f1anatic
post Nov 19 2005, 02:41 PM
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Originally Posted by RobY
There are many types of Subaru AWD systems the most advanced being the 5eat and the STI DCCD which are offshoots of the WRC Rally car. Using a planetary gear center differential slip limited by electromagnetic cam locking clutch packs. The STI having torque sensing differentials in the axles in addition. It is in fact the most advanced and performance oriented system currently available. This system allows individual wheel movement while using steering and yaw sensor to proportion torque front or rear to where it sees fit. In the STI the bias is variable and driver definable through a selector switch.

The torque proportion is done through true electronicly variable limited slip differentials and works at all speeds.

This is not to be confused with Haldex which is merely a coupling see link below...

How does it compare to the current generation quattro AWD? There is really no comparison the above system is better in almost every way.

It works completely unloaded the electromagnetic cam locking clutch pack lsd has locking capability.

Whereas the quattro has one 2.3:1 bias ratio torsens. If you ever get your front wheels stuck in a low tractive condition the quattro torsens can send a maximum of 2.3 times the force that cause the front wheels to spin. If your front wheels spin at 10lb/ft of torque because you are on ice the maximum your rears will get is 23 lb/ft. The rest of the power will leak out through the front wheels that are stuck. If one set of wheels become completely unloaded the torsens wont work all the power will leak out the unloaded wheels.

The newest Quattro system uses brakeforce psudo differentials that simply use the brakes and ABS system to apply brake force to bias power side to side. seems like a great idea but unfortunately these brakeforce psudo diffs only work under 25mph. If you use it too much you will overheat the brakes.

Performance wise it can bias power based on computer controlled attributes and is not set to a preset torsens bias ratio.


The 5mt subaru is continuous AWD with a 50:50 torque distribution slip limited by a viscous coupling. Brutally effective as it allows each set of wheels to receive an absolute torque split of 50:50 while still allowing each wheel to move independently of each other. Under normal conditions the viscous coupling is stationary and does no work. If one wheel becomes unloaded slip is limited by a viscous coupling differential that works in any condition even if the wheels are completely unloaded.

This system works through differentials slip limited by viscous couplings and works at all speeds.

This system is NOT to be confused with a much simpler viscous coupling it is very diffrent. Whereas primary torque transfer in a viscous coupling is through viscous fluid. The primary torque transfer in the Subaru Viscous Copling Locking Differential System is through mechanical differentials whose slip is limited BY viscous differentials.

Compared to quattro it has a disadvantage because it does not have variable torque distribution through a center torsens.

However this system like the above sytem has viscous locking LSD capability and can work with the wheels completely unloaded. Side to side bias in performance models work through real viscous differentials and will work at any speed and completely unloaded.

The lower line automatic transmission subarus use a haldex type coupling.

Ive commented on this topic before....

http://www.legacygt.com/forums/show...p?t=8474&page=2


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Valentin50014
post Nov 20 2005, 01:48 PM
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Mersi f1anatic am zabavit mai mult timp pe forumul recomandat de tine. Am aflat multe lucrui interesante, cum ar fi faptul ca Legacy are cate un diferential normal (open) pe fiecare axa. :shock: :shock: :shock: Pentru cei mai putin obisnuiti cu denumirile aste, open diferential inseamna banalul diferential care se gaseste pe orice masina, numai ca sunt 2. Cu alte cuvinte, in cazul in care pierde tractiunea cu o roata pe fiecare osie, Subaru are nevoie de un tractor s-o scoata... blush.gif

George, ai grija cand te duci la peste, ia un prieten cu quattro cu tine... nu se stie niciodata


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Valentin50014
post Nov 20 2005, 02:01 PM
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Daca ieri mai aveam un dubiu, acum nu mai am niciunul smile.gif quattro e mult mai performant.

Baiatul asta, pe care l-ai citat tu aici, face ceea ce a facut Nissan mai devreme. Compara cea mai noua versiune AWD de la Subaru cu o versiune mult mai veche de quattro.

QUOTE(f1anatic)
Originally Posted by RobY
Whereas the quattro has one 2.3:1 bias ratio torsens. If you ever get your front wheels stuck in a low tractive condition the quattro torsens can send a maximum of 2.3 times the force that cause the front wheels to spin. If your front wheels spin at 10lb/ft of torque because you are on ice the maximum your rears will get is 23 lb/ft. The rest of the power will leak out through the front wheels that are stuck. If one set of wheels become completely unloaded the torsens wont work all the power will leak out the unloaded wheels.

Tipul ori nu cunoaste modul de functionare al diferentialului torsen, ori e rau intentionat. Problemele aste le avea quattro demult, nici vorba de asa ceva acum.

QUOTE(f1anatic)
The newest Quattro system uses brakeforce psudo differentials that simply use the brakes and ABS system to apply brake force to bias power side to side. seems like a great idea but unfortunately these brakeforce psudo diffs only work under 25mph. If you use it too much you will overheat the brakes.
Dar de EDL nu a auzit? Parca si Golf-ul 3 avea EDL. Si iar e simpatic.... Adica se uzeaza si/sau se incalzesc placutele de frana? Franarea se face doar la pierderea aderentei, energia degajata este nesemnificativa in comparatie cu energia degajata la o franare normala. Daca placutele rezista la franare nici nu se vor incalzi in timpul functionarii diferentialului. Acest sistem se foloseste la multe din masinile off-road adevarate. (Hummer-ul militar, Land Rover etc). Dar repet, acum se folosesc dispozitive elctronice de blocare.

QUOTE(f1anatic)
The 5mt subaru is continuous AWD with a 50:50 torque distribution slip limited by a viscous coupling. Brutally effective as it allows each set of wheels to receive an absolute torque split of 50:50 while still allowing each wheel to move independently of each other. Under normal conditions the viscous coupling is stationary and does no work. If one wheel becomes unloaded slip is limited by a viscous coupling differential that works in any condition even if the wheels are completely unloaded.

This system works through differentials slip limited by viscous couplings and works at all speeds.

This system is NOT to be confused with a much simpler viscous coupling it is very diffrent. Whereas primary torque transfer in a viscous coupling is through viscous fluid. The primary torque transfer in the Subaru Viscous Copling Locking Differential System is through mechanical differentials whose slip is limited BY viscous differentials.


Diferentialele LSD (prin viscocuplaj) au si avantaje si dezavantaje. Cel mai important avantaj fata de torsen este acela al costului, sunt mult mai ieftine datorita simplitatii lor. Ca dezavnataje, ar fi urmatoarele:
1. O intarziere in reactie. Pentru ca ele sa devina eficiente, lichidul trebuie sa se incalzeasca (datorita frecarii cauzata de vitezelor de rotatie diferite).
Cu alte cuvinte, roata trebuie sa patineze destul inainde ca diferentialul sa intervina.
Este adevarat, ele functioneaza si cand lichidul este rece, dar diferenta de tractiune pe care o indrepta catre o osie sau alta in acest caz nu este foarte mare. In cazul torsen, viteza este mult mai mare. Este necesar ca o roata sa se invarta cu doar 15 grade mai multa decat cealalta si intregul cuplu necesar este indreptat unde trebuie.
2. Dependenta fata de temperatura exterioara. Cu cat este mai rece, cu atat se incalzeste mai greu lichidul.

QUOTE
Comparison with other types of differentials

Primul exemplu de diferential de pe Subaru, postat de f1anatic
Other means are also known for modifying the operative connection between drive axles to provide for the transfer of additional torque to the drive axles collectively. For example, many limited-slip differentials provide for preloading friction clutches to oppose the transfer of torque between drive axles. This frictional pre-load represents a particular minimum magnitude of resistance which must be overcome to permit any relative rotation between drive axles which may interfere with the operation of anti-lock braking systems. Also, since frictional forces are continually active to resist differentiation, the friction clutches tend to wear, resulting in a deterioration of intended differential performance.

In contrast to the limited-slip's continuous magnitude of frictional resistance to differentiation, the
torque biasing characteristic of the Torsen differential provides for a maximum ratio of torque
distributions between drive axles. For instance, as the amount of torque being conveyed by the
Torsen differential decreases, the amount of resistance to differentiation also decreases. That is, even though the bias ratio remains relatively constant, a proportional division of a lower magnitude of torque being conveyed by the differential results in a smaller torque difference between drive axles. In braking situations where little or no torque is being conveyed by the differential, a four to one apportionment of torque between drive axles amounts to little or no torque difference between drive axles. Thus, the Torsen differential will not support any appreciable torque 'wind-up' between drive axles during braking and so does not interfere with the operation of anti-lock braking systems.

Al doile tip de diferential LSD de pe Subaru, din nou Torsen este mai performant
Another known approach to modifying the operative connection between drive axles is to provide for resisting differentiation as a function of the speed difference between drive axles. It has long been appreciated that undesirable wheel slip is associated with very high rates of differentiation. Differentials have been designed using fluid shear friction, which respond to increased rates of differentiation by increasing fluid shear frictional resistance to differentiation. The obvious problem with such 'speed sensitive' differentials is that undesirable wheel slip has already occurred well in advance of its detection. Also, the fluid shear friction designs generally rely on the changes in fluid temperature associated with high differential shear rates to increase resistance to differentiation. However, similar temperature changes may be associated with extended periods of desirable differentiation, or may be influenced by changes in ambient temperature, so that resistance to differentiation may vary throughout ordinary conditions of vehicle use.

The bias ratio characteristic of the Torsen differential instantly reacts to unequal traction conditions by delivering an increased amount of torque to the drive wheel having better traction before the other drive wheel exceeds the limit of traction available to that wheel. The bias ratio characteristic also remains substantially constant over a wide range of torque conveyed by the differential, and is not sensitive to changes in ambient temperature or conditions of vehicle use.


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Valentin50014
post Nov 20 2005, 02:11 PM
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QUOTE
Now what happens if one of the drive wheels has good traction, and the other one is on ice? This is where the problem with open differentials comes in.

Remember that the open differential always applies the same torque to both wheels, and the maximum amount of torque is limited to the greatest amount that will not make the wheels slip. It doesn't take much torque to make a tire slip on ice. And when the wheel with good traction is only getting the very small amount of torque that can be applied to the wheel with less traction, your car isn't going to move very much

Deci daca o roata pe fiecare osie patineaza, Legacy 2.5 ramane blocat. La quattro este suficient ca doar o singura roata sa aiba tractiune din cele 4.

QUOTE
Another time open differentials might get you into trouble is when you are driving off-road. If you have a four-wheel drive truck, or an SUV, with an open differential on both the front and the back, you could get stuck. Now, remember -- as we mentioned on the previous page, the open differential always applies the same torque to both wheels. If one of the front tires and one of the back tires comes off the ground, they will just spin helplessly in the air, and you won't be able to move at all


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Valentin50014
post Nov 20 2005, 02:23 PM
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Aici este descrisa functionarea primului diferential LSD (cel amintit de tipul citat de f1anatic de pe forumul subaru)

QUOTE
This type of LSD has all of the same components as an open differential, but it adds a spring pack and a set of clutches. Some of these have a cone clutch that is just like the synchronizers in a manual transmission.

The spring pack pushes the side gears against the clutches, which are attached to the cage. Both side gears spin with the cage when both wheels are moving at the same speed, and the clutches aren't really needed -- the only time the clutches step in is when something happens to make one wheel spin faster than the other, as in a turn. The clutches fight this behavior, wanting both wheels to go the same speed. If one wheel wants to spin faster than the other, it must first overpower the clutch. The stiffness of the springs combined with the friction of the clutch determine how much torque it takes to overpower it.

Getting back to the situation in which one drive wheel is on the ice and the other one has good traction: With this limited slip differential, even though the wheel on the ice is not able to transmit much torque to the ground, the other wheel will still get the torque it needs to move. The torque supplied to the wheel not on the ice is equal to the amount of torque it takes to overpower the clutches. The result is that you can move forward, although still not with the full power of your car.

Nu cred ca mai sunt necesare comentarii suplimentare...


QUOTE
Viscous Coupling
The viscous coupling is often found in all-wheel-drive vehicles. It is commonly used to link the back wheels to the front wheels so that when one set of wheels starts to slip, torque will be transferred to the other set.

The viscous coupling has two sets of plates inside a sealed housing that is filled with a thick fluid, as shown in below. One set of plates is connected to each output shaft. Under normal conditions, both sets of plates and the viscous fluid spin at the same speed. When one set of wheels tries to spin faster, perhaps because it is slipping, the set of plates corresponding to those wheels spins faster than the other. The viscous fluid, stuck between the plates, tries to catch up with the faster disks, dragging the slower disks along. This transfers more torque to the slower moving wheels -- the wheels that are not slipping.

When a car is turning, the difference in speed between the wheels is not as large as when one wheel is slipping. The faster the plates are spinning relative to each other, the more torque the viscous coupling transfers. The coupling does not interfere with turns because the amount of torque transferred during a turn is so small. However, this also highlights a disadvantage of the viscous coupling: No torque transfer will occur until a wheel actually starts slipping.

Acesta este despre cel de-al doilea exemplu de diferential performant de la Subaru. Este performant, dar nu mai mult decat torsen


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Valentin50014
post Nov 20 2005, 02:35 PM
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Locking and Torsen
The locking differential is useful for serious off-road vehicles. This type of differential has the same parts as an open differential, but adds an electric, pneumatic or hydraulic mechanism to lock the two output pinions together.

QUOTE
This mechanism is usually activated manually by switch, and when activated, both wheels will spin at the same speed. If one wheel ends up off the ground, the other wheel won't know or care. Both wheels will continue to spin at the same speed as if nothing had changed.

The Torsen differential is a purely mechanical device; it has no electronics, clutches or viscous fluids.

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.

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
Ultima afirmatie este perfect adevarat, dar a fost depasita demult de Audi. A fost aleasa solutia franarii automate a rotilor care patinau, sau mai nou, EDL-ul. Adica cand intreaga osie patineaza o varianta electronica si automata a lock-ului manual este folosita pentru a bloca osia respectiva. Din acest motiv la quattro este suficient sa ai doar o singura roata cu tractiune si cuplul va fi indreptat acolo.


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Valentin50014
post Nov 20 2005, 02:43 PM
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Inca un fragment interesant:

QUOTE
Unfortunately, limited slip differentials (LSD), available as options for many 4x4 in the US are offered by sales people as "locking differentials". A confusing term because nothing on these differentials is LOCKING. They are by far inferior to a differential that is truly lockable.
If you have to decide whether to get a "locking differential" (LSD) or not I would still recommend getting it because it is still better than not having anything at all.

To repeat: "locking differentials" are limited slip differentials that are not to be confused with differential lock!

Differential lock = differential locks = differential locker = diff lock
= diff locks = diff locker


It seems to me, that manufacturers and dealers prefer to use the term "locking differential" over the correct term "limited slip differential" because it sounds more like the real thing - even though it is not. Is this already consumer fraud?


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Valentin50014
post Nov 20 2005, 03:09 PM
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QUOTE(Iulian HondaFan)
ATTESA-ETS, sistemul AWD al Nissan care e original prin faptul ca variaza cuplul transmis fata:spate de la 0:100 pana la 50:50.

spre deosebire xi al BMW transmite pe spate maxim 62%, 4matic al Mercedes 60% iar quattro numai 50% din cuplu.
Aici cred ca faci o confuzie. 50% spate reprezinta distributia normala a cuplului, atunci cand toate rotile au tractiune si se ruleaza cu viteza constanta. Chiar tu ai spus in primul link ca quattro permite transferul a 66% din cuplu pe spate.
In noua versiune de quattro, distributia normala de cuplu este de 40% fata si 60% spate. In conditiile pierderii aderentei, transferul poate ajunge pana la 100% pe oricare dintre osii. Revin imediat cu detalii


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Valentin50014
post Nov 20 2005, 03:30 PM
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Noua generatie de quattro
QUOTE
The challenge, of course, is to get all this power on to the road in perfect style and with optimum handling. And for no less than 25 years, Audi’s answer to all the particular requirements in this respect has been that magical name “quattro”. Now the latest generation of Audi’s permanent four-wheel drive featured for the first time in the RS 4 offers asymmetric/dynamic torque distribution and a self-locking Torsen centre differential, making a significant contribution in enabling the RS 4 with its sports suspension to enter new dimensions in driving dynamics. Indeed, Audi quattro technology still provides traction when other drive concepts have long reached their limits. And in this case quattro drive is further enhanced by Audi’s DRC Dynamic Ride Control, significantly reducing both body roll and dive.




QUOTE
The S4 25quattro features the latest generation of quattro drive specifically designed for the sportiest Audis with asymmetric/dynamic distribution of engine power and torque. The Torsen power divider delivers the output and torque of the engine individually to the front and rear axle as required, thus ensuring optimum traction at all times: reflecting even minor changes in road conditions, the flow of power is re-directed immediately as a function of torque, with up to 100 per cent of engine power and torque going to just one axle whenever appropriate. This new distribution of drive power makes the Audi S4 quattro an even more dynamic performer on the road. The term “Torsen” comes from “torque” and “sense”, which, taken together, quite literally means “sensing the development and build-up of torque.” The Torsen differential is a self-locking worm gear system building up its locking action only under power, while allowing differences in speed both when applying the brakes and in bends.

http://www.autoblog.com/entry/1234000670054157

Si iata ce zice audi:
QUOTE
On the permanent all-wheel drive quattro® power is distributed as needed to all four wheels. This system provides high levels of active safety, and dependable traction on virtually all surfaces as well as excellent road holding, even in cross-winds. It is superior to manual all-wheel-drive systems because of this “permanent safety advantage”. The Audi RS 4 and S4 quattro® drive, with asymmetric/dynamic distribution of torque, transfers up to 100 percent of available driving torque to the front or rear axle if required


Am sa revin cu detalii si despre Haldex


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Iulian HondaFan
post Nov 20 2005, 04:43 PM
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QUOTE(Valentin50014)
Mersi f1anatic am zabavit mai mult timp pe forumul recomandat de tine. Am aflat multe lucrui interesante, cum ar fi faptul ca Legacy are cate un diferential normal (open) pe fiecare axa. :shock: :shock: :shock: Pentru cei mai putin obisnuiti cu denumirile aste, open diferential inseamna banalul diferential care se gaseste pe orice masina, numai ca sunt 2. Cu alte cuvinte, in cazul in care pierde tractiunea cu o roata pe fiecare osie, Subaru are nevoie de un tractor s-o scoata... blush.gif

George, ai grija cand te duci la peste, ia un prieten cu quattro cu tine... nu se stie niciodata


din cate stiu Forester, Legacy si Impreza au limited slip differential (LSD) pe spate. STI are LSD si pe fata si pe spate.

precizari:

1)diferentialele blocabile (locking diffs) nu sunt de dorit. acestea sunt cele folosite in sistemele 4WD care in efect impart cuplul 50-50 intre cele 2 axe.

2)LSD (diferentialele autoblocabile) sunt cele de dorit. acestea trasmit cuplul de la rotile care patineaza la rotile care nu patineaza. toate sistemele AWD au un diferential central autoblocabil.

diferentialele obisnuite fac opusul. daca o roata patineaza atunci cuplul este transferat de la roata cu tractiune la cea fara tractiune.

EDL-ul (electronic differential lock) franeaza roata care patineaza in felul asta diferentialul simplu transfera cuplul catre roata opusa. EDL e util la un diferential obisnuit dar nu se compara cu un LSD mecanic.

sistemul quattro de pe RS4/S4 nu este acelasi cu quattro de pe A4.

diferentialele centrale mecanice (torsen sau haldex) sunt teoretic superioare celor prin vascocuplaj. incalzirea siliconului respectiv este insa foarte rapida si viteza de reactie este f. buna chiar daca nu este cvasi-instantanee ca la cele mecanice.


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Valentin50014
post Nov 20 2005, 04:51 PM
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He he he. Intreaba-l pe George, el stie mai bine.

Arunca o privire pe aici...
http://legacygt.com/forums/showthread.php?t=18723


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Iulian HondaFan
post Nov 20 2005, 05:28 PM
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e posibil. varianta GT are rear axle LSD:

QUOTE
ROADABILITY: As mentioned, the fourth-generation Legacy's unibody structure has greater rigidity than that of its predecessors. Use of aluminum in the hood and the wagon's tailgate lowers weight a little, and, as importantly, helps centralize mass for better cornering ability. All of the MacPherson front suspension components, and most of the multilink rear, have been redesigned, resulting in improved ride comfort and excellent cornering manners. Road manners are also helped by full-time all-wheel drive. Manual-transmission Subarus like my test car use a system with a mechanical system with a viscous-coupling locking center differential to distribute torque 50/50 between the front and rear axles. Wheel slip at either end will send torque to the opposite set of wheels; side-to-side torque distribution is helped at the rear by a viscous limited-slip differential. GT models get slightly quicker steering for better response. Handling is delightfully neutral, with none of the massive understeer (``push'') commonly exhibited by front-wheel cars. Powerful four-wheel antilock ventilated disc brakes stop securely.


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f1anatic
post Nov 20 2005, 05:32 PM
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Ma pregateam sa plec la vinatoare cind am postat link-ul si textul. Nu l-am citit complet si atent...dar ori aluia ar trebui sa ii fie luat-a Legacy or tu intzelegi si interpretezi rau voit si gresit.

Subaru Legacy GT are diferentziale LSD (limited slip differentials - pe centru si pe spate. STi-urile au si pe fatza...si in plus au DCCD - Driver Controlled Center Differential (care permite blocarea diff. central intr-un raport fix ....ex. 30% fatza si 70% spate). Cei mai multzi mesteri cu STi il lasa pe control automat...in care caz, masina se comporta ca sistemul VTD.

Daca citesti...CU ATENTZIE...sistemul VTD reprezinta diff. controlate de electromagnetzi care variaza distributzia cuplului fatza spate ...deci variabil cu raportul normal 45%F-55%S. Ce s-a chinuit omul acela fara success sa explice este ca sint diferentziale mecanice al carei raport este limitat de fluid viscos. Nu este fluidul viscos care le angreneaza.

Al punct de vedere valid este treaba cu frinele si ABS-ul care incearca sa creeze tractziune prin blocarea rotzilor. Daca esti pe gheatza...tu s-ar putea sa itzi prajesti frinele stind pe loc. La mine, rotzile se vor invirti.

Asa ca good luck.

EDIT: NU STIU CUM SA STERG IMAGINEA...A FOST ATASATA PRIN FORUM.


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f1anatic
post Nov 20 2005, 05:51 PM
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QUOTE
The all-wheel-drive system in the Legacy models differs in technical details by drivetrain: When fitted with the manual transmission, the all-wheel-drive system uses a viscous coupling, a locking center differential that splits the engine's power between the front and rear wheels; if the tires at one end begin to slip, the system sends more power to the other end; optimally, the split is 50/50, but power transfer can reach 100 percent to either end under extreme conditions. The four-speed automatic is matched with an electronically managed, continuously variable transfer clutch that distributes the power where it's best used, but no more than 50/50. The five-speed automatic transmission brings with it the most technologically advanced of Subaru's all wheel-drive system, the VTD, for Variable Torque Distribution. An electronically controlled, continuously variable hydraulic transfer clutch manages the power distribution through a planetary center differential. Under normal conditions, the VTD splits the power 45/55 front/rear to give the GT more of a rear wheel-drive feel, but adjustments, to a maximum of 50/50, are made as road conditions dictate. All of these systems give the Legacy a sure-footed feel and greatly improve grip and handling stability in slippery conditions.

http://www.woio.com/global/story.asp?s=2969795

I don't know man. Crezi ce vrei. OK...orice ar fi...sa stii ca AUDI e mai fraiera ca BMW si bineintzeles....Subaru este uin Groapa Marianelor (sau cum se numeste naibii) iar BMW este pe Everest. Iar AUDI este la nivelul marii.

Crezi ce vrei...sustzii ce vrei...este o lume libera. Atita doar...masina mea saracacioasa si amarita...poate trimite puterea fatza spate ...ad libitum si dreapta stinga ad libitum. Nu are traction control...deci pe gheatza...frinele nu imi vor fi actzionate...iar senzorii vor simtzii ce rotzi se invirt in gol si trimit puterea la alea care au mai multa tractziune. Si cind nu am sa mai pot merge mai departe...chem un tractor...si pe urma merg cu el sa te scoata si pe tine din zapada in care esti intzepenit.

BMW rulzzz ! AUDI rulzzz too dar mai putzin. Subaru deeply sucks until it hurts. Toata lumea e happy. Peace...am lucruri mai importante de facut.


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Iulian HondaFan
post Nov 20 2005, 05:55 PM
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pai, da se pare ca Legacy-ul 2.5 american nu are LSD pe spate. acesta este oferit numai pe varianta GT. e posibil insa ca varianta europeana sa aiba autoblocabil pe spate.

STI rules! are LSD fata spate si centru!!!

si Outback vine cu LSD pe spate.

o concluzie: NU VA LUATI DUPA RECLAMA!!! daca vreti sa cumparati AWD interesati-va de tipul de diferentiale folosite!!!. un sistem AWD care nu are macar LSD pe spate nu prea se merita ( ex. rotile de pe dreapta sunt in namol, nu va veti putea misca de acolo fara un LSD chiar daca transferul fata spate se poate face).


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Valentin50014
post Nov 20 2005, 06:14 PM
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1. Mr f1anatic, cred ca ai o problema... Nu poti discuta normal? Nu ma intereseaza prea mult persoana ta si o pot ignora daca iti provoaca mai multa placere. Nu am vrut decat sa intelegem fiecare mai mult despre cele doua tehnologii...
2. Unde am spus eu ceva de Legacy GT? Vorbeam de 2.5-ul lui Gerorge.
3. Citeste inca o data ultimul link pe care l-ai pus tot tu si fa o comparatie cu quattro. Se pare ca unul dintre noi intelege diferit limba engleza. Sunt sigur ca vei intelege unde torsen este superior.
4. Ocorda o mai mare atentie cuplului disponibil pe cele doua axe...


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Valentin50014
post Nov 20 2005, 06:18 PM
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Iulian, ai perfecta dreptate. Un open diferential "de ultima generatie" am si pe Golf-ul din semnatura. Acest tip de diferential este util daca una din roti nu pierde aderenta.
De asemenea, LSD-ul rulz in comparatie cu celelalte variante de diferentiale de pe Subaru, in fata concurentei.... nu prea

De asemnea, fiti atenti la termenii folositi in articolul postat de f1anatic. iar se ascunde ceva sub binecuvantarile marketingului. Sunt curios, cate off road-ere adevarate folosesc LSD? Oare de ce?

Mr f1anatic, imaginea atasata de tine nu are nici un rost aici luand in considerare discutia de aici si nu-ti sustine punctul de vedere. Eu nu vorbeam de masina ta ci de cea a lui Geroge. Fi bun si sterge imaginea ca nu face decat sa strice alinierea topicului...


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Iulian HondaFan
post Nov 20 2005, 06:28 PM
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pai, marea majoritate a FWD vin cu diferentiale deschise. unele au EDL. doar unele modele sport au front LSD.

apropos, stie cineva daca ESP-ul Bosch include standard si EDL? din cate stiu traction control (TC) este automat inclus in ESP, dar intrebarea este daca TC si EDL sunt compatibile?

da si eu zic sa pastram discutia pe acest topic pe termeni tehnici.

Valentin quattro de pe A4 are LSD? dar la generatia precedenta?


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G e o r g e
post Nov 20 2005, 06:55 PM
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legacy 2.5i are diferentiale deschise fata / spate . asa si ?

ps tocmai am venit de la munte smile.gif 2 masini nu au avut nici o problema in a se deplasa prin zapada : un X5 si un ... legacy

S-uri 3 trase pe dreapta , unul a intrat in parapet chiar langa mine blink.gif
passaturi , octavii , A4, muuuulte care dansau intr-o veselie .

si chiar cu anvelope de iarna aveau ceva probleme in a iesii din acele de par blush.gif

asa ca , troaca mea , face fata cu brio chiar cu diferentiale deschise .


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f1anatic
post Nov 20 2005, 08:13 PM
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QUOTE(Iulian HondaFan)
o concluzie: NU VA LUATI DUPA RECLAMA!!! daca vreti sa cumparati AWD interesati-va de tipul de diferentiale folosite!!!. un sistem AWD care nu are macar LSD pe spate nu prea se merita ( ex. rotile de pe dreapta sunt in namol, nu va veti putea misca de acolo fara un LSD chiar daca transferul fata spate se poate face).


Vrei sa zici BMW 330 xi ?

De pe Edmunds.com, m-am dus la BMW 330 xi sedan si apoi am comparat-o cu AUDI A-4 respectiv 2006 Legacy GT

Drivetrain 3 Series A4 Legacy
Driven Wheels all wheel drive all wheel drive all wheel drive
Center Differential Not Available mechanical viscous
Limited Slip Differential - Rear Not Available Not Available Standard
Limited Slip Differential - Center Not Available Standard Standard


2006 BMW 3 Series
325xi 4dr Sedan AWD (3.0L 6cyl 6M)

2006 Audi A4
2.0T quattro 4dr Sedan AWD (2.0L 4cyl Turbo 6M)

2006 Subaru Legacy
2.5 GT Limited 4dr Sedan AWD w/Black Int. (2.5L 4cyl Turbo 5M)

Pai e clar. In priviintza sistemelor AWD, BMW este fara nici un dubiu pe primul loc, urmat de AUDI si pe locul 4 (intr-o comparatzie de 3 masini) este Subaru Legacy - masina saracului.

http://www2.uic.edu/~bcatal1/etcetera/suba...AUDI.SUBARU.pdf

Comparatzile si voi si vedetzi de ce Subaru e a mai fraiera si BMW a mai buna. Mai ales la AWD.


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