Valentin, nu mai ai dreptate cu STI-ul. STI-ul anul acesta primeste un LSD mecanic.

Cel de pe STI, cum am mai spus, este similar xdrive, 4matic si haldex. Ce are in plus? Faptul ca se poate ajusta tractiunea de catre sofer, la ceilalti fiind numai automat. Ce importanta are, nu cred ca are. Ar trebui sa intrebam un pilot de raliuri

pe de alta parte tu accentuezi elementul teoretic. ti-am exemplificat ca la 225CP o impreza este mai rapida decat un TT quattro. iar un A4 3.2V6 255CP este mai incet decat un Legacy GT cu 250CP. este greu sa ramai intepenit cu FWD ( mie in 5 ani de condus mi s-a intamplat 1 data) si iti spun ca daca bagi A4 quattro in balarii o sa-ti para tare rau de el. quatro nu este un sistem off-road ci on-road.

iar graficele despre tractiune sunt valabile exclusiv pe asfalt. pe zapada sau nisip ori noroi " dig for traction phenomenon" este f. important. asta e exemplificat si de alegerea cauciurilor cu crampoane pe off-roadere.

Valentine, man...you're losing it...

In primul rind...pui atit accent pe situatzie de asfalt (uscat) incit...e clar ca nici tu nu realizezi ce sustzii.

Masinile alea trebuie ca aveau lantzuri de tractaj pe dedesupt. Panta de 80% = 72 grade ? Pai in curind ne vei spune ca pot sa mearga pe perete ?

Press Coverage :
The new midsize 2005 Subaru Legacy, debuting in Spring 2004, has sharper new styling boasting a very aerodynamic Cd is 0.28 for the sedan and 0.30 for the wagon. The chassis changes slightly, with a 20mm longer wheelbase. The lighter new Legacy is also 35mm wider, 30mm longer and 15mm taller than the outgoing model. But the big news is the huge power upgrade for the top model.
The US-spec Legacy GT model will now have a turbocharged 2.5L 4 cylinder boxer engine featuring AVCS variable valve timing. Essentially the same engine used in the Impreza WRX STi, but detuned in this application, it has more than 80 extra horsepower over the weak outgoing model. This US-spec engine is larger than the Japan-spec 2.0L turbo engine, but the Japanese engine has a higher power output of 280 hp, versus the 250 hp of the US-spec engine.

On April 23, 1998 a Subaru Legacy set a new world speed record for mass-produced turbo station wagons (1600 cc–2000 cc class), clocking 270.532 km/h over one kilometer on Highway 10 in La Junta, Colorado. [1] (http://www.subaru-global.com/about/history/1998-001.html) This record was previously set by a Generation II Subaru Legacy in 1993.

The suspension is helped by 18-inch wheels and Bridgestone RE050A rubber - of Ferrari Enzo fame - with the rubber compound tuned for the Legacy. Although the Legacy's 2.0-liter bears a strong resemblance to the 2.5-liter STi motor on paper, it's in fact the motor STi appropriated for the WRX STi 8 (not sold in America). And it makes the same amount of horsepower as that car, but not quite the same amount of torque -250 lb-ft vs. 285 lb-ft.

Iulian, ceea ce spui tu aici am mai discutat. Performantele unei masini, in ansamblui ei, nu ne pot arata performanele unui sistem AWD. Daca Subaru sau Audi ar folosi aceleasi sistem atunci da. Un motor turbo este mult mai bun decat unul aspirat datorita distributiei mai largi a cuplului, in plus Audi este cu peste 100 g mai greu, plus cutia. Tie ti se pare corecta comparatia? Daca discutam de performante, este clar peste A4, peste quattro ma indoiesc. Pretul este normal sa fie mai mare, este o marca premium. Lexus de ce costa mai mult?

Apropo de cuplu la turbo: TFSI-ul tau are curba de cuplu extraordinara imposibil de atins pt. un aspirat: 180Nm@1800-5000Scuza-ma, arata-mi un motor aspirat de cu aproximativ aceeasi putere si acelasi cuplu si care sa iaba o astfel de distributie a cuplului...
3.2 comparat de tine are 330 Nm@3250. Este o mare diferenta...

Acura, R32, BMW, TT ce cauta in mesajul tau? Ce legatura au cu quattro (torsen)

Tu ai citit ce scrie in acel film? Chestiile alea erau pentru securitate, data oprita masina aceasat aluneca inapoi si se facea praf. Prin faptul ca au arata exact ceea ce au facut dovedeste faptul ca au jucat cinstit, era foarte usor sa le ascunda in film. Si stai linistit, cei de la Audi nu erau singuri acolo, era plin de lume pe acolo, oficiali sau gura casca... Apropo, a repetat figura de 11 ori...
Mai multe detalii aici...
http://www.germancarfans.com/news.cfm/newsid/2050308.004
Acesta reprezinta clar un record mondial. Daca ar fi fost la indemana tuturor, multe firme ar fi repetat performanta ceea ce le-ar fi adus o reclama extraordinara...

fanatic, eu am cerut un link in care sa se vorbeasca de aceasta limitare la ESP 8. Tu-mi aduci link-uri de acum 10 ani (cel de pe forumul audi). Oricum, misetrul meu a fost dezlegat chiar de catre situl Audi. Intr-adevar, la quattro EDL-ul functioneaza pana la 80 km/h.

MR, tu confunzi ASR-ul cu EDL-ul. EDL-ul nu reduce nimic, nu trebuie sa deconectezi nimic, pur si simplu functioneaza si te scoate...
Geroge, repet. tu ai acelasi sisetm de blocare de pe Audi gata stricat

fanatic, ce zici, facem o comparatie intre AWD Subaru si Audi pe clase? Incepe tu.
Legacy (european) vs A4
Legacy GT vs A4
Outback, Forester vs Allroad, Toareg (Q7)
STI vs R32 (nu mai e nevoie, STI-ul este mult deasupra)
Ce zici? fara multe detalii, doar ce are + sai - fiecare, pe scurt
Iulian, tu ce spui?

Pe Paul Hansen il stiu prin reputatzie si de pe forumul nostru cu Subaru (e japonez...)
http://www.sportcompactcarweb.com/roadtests/0306scc_legacy/

Mie nu mi-e clar daca bugatti are motor vag sau audi are motor bugatti

Since the launch of the original Audi quattro (also known as "Urquattro"), the Volkswagen-Audi Group have developed, tested and deployed various four-wheel drive systems for their cars.

For years, the systems and the brand names were interchangeable. This changed when VAG introduced the Swedish Haldex clutch as a part-time 4WD solution for their smaller cars with transversely mounted engines. From that moment on, quattro was no longer a system but a brand name for Audi 4WD cars. Conversely, 4motion was introduced as a brand name for VW's 4WD cars. Depending on engine lay-out, quattro and 4motion can now point to both Quattro IV and Haldex systems.

Here's a rundown of VAG's 4WD systems and brand names used over the years. This is followed by a brief explanation of the various types of differentials used by 4WD car manufacturers.

Brand names

Audi: quattro
VW: syncro, followed by 4motion
Seat: 4
Skoda: 4x4

Systems

Quattro I: open front diff, open center diff (manual lock), open rear diff (manual lock). No ABS when locked.

Full-time manually engaged four-wheel drive.

Was on: original Audi quattro (also named "Urquattro"), Audi 80/100 quattro.

Syncro: open front diff, viscous coupling acting as the center diff, open rear diff.

Part-time automatically engaging four-wheel drive.

Was originally developed by Audi, but sourced to VW as "syncro". Similar line of thought to the Haldex system, with the VC engaging rear drive when needed. Crude system with serious drawbacks, such as a lack of ABS integration, which needed the 4WD system to be switched off under braking, using a secondary clutch. Volvo also went on to use it on their earlier Cross-Country models, adding a TC system at the front and an LSD at the back - complicated and flawed. Also on 911 Carrera 4, but then that's originally a RWD car...

Quattro II: open front diff, torque sensing ("torsen") center diff, open rear diff (manually lockable for "those" situations in the rough). No ABS when rear is locked, auto de-lock when speed exceeds 15mph.

Full-time automatically engaged four-wheel drive.

Was on: the Audi quattro ('88-'91, still nicknamed "Urquattro"), Audi 80/90 quattro, Audi 100/200 quattro, Audi Coupé quattro, Audi S2/RS2, Audi S4, Audi S6 (all until '95). Usually seen as the quattro system.

Quattro III: open front diff, torsen center diff (auto version: planetary gear center with electronically controlled multi-plate locking clutch), torsen rear diff.

Full-time automatically engaged four-wheel drive.

Was on: Audi V8/A8 between 1990 and '94. Quattro II further perfected. The ideal all-mechanical system.

Quattro IV: open front diff with Electronic Differential Lock (EDL), torsen center diff, open rear diff with EDL.

Full-time automatically engaged four-wheel drive.

Is on: all VW/Audi cars with longitudinally mounted engines, so A4/A6/A8 quattro, S4/S6/S8, RS4/RS6, Passat 4motion. Quattro with a blend of electronic wizardry, with ABS/ASR sensors acting to detect slipping wheels (the EDL system). First 4WD system which theoretically needs to have all four wheel slipping before it's rendered unmovable.

Haldex: open front diff with EDL, electronically controlled Haldex clutch center, open rear diff with EDL.

Part-time automatically engaging four-wheel drive.

Is on: all VAG cars with transversely mounted engines, so Audi A3 quattro, S3, TT quattro, VW Golf/Bora 4motion, Seat Leon 4, Skoda Octavia 4x4. Normally FWD but Haldex directs torque to the rear when slip occurs to a maximum torque split of 50/50. Is also the system of use in the latest Volvo AWD models (S60, V70, XC70).

Differentials/clutches

Open diffs are the most common type of diff. Wheels (or axles on a 4x4) can turn freely relative to each other. They have no means of balancing power delivery if one wheel has less traction than the other.

Limited-slip diffs (or LSDs) allow the two wheels to turn relative to each other, but limits the rate at which they are allowed to do so (usually either by some sort of friction or fluid coupling). This ensures that, even if one wheel loses traction, some power is still delivered to the other.

Lockable diffs (not to be confused with EDL) physically lock the two half-axles together. This is fine for off-road travel, but can cause problems when trying to turn on high-grip surfaces - one wheel gets "dragged" around.

The electronic differential lock (EDL) employed by VAG is not - as the name suggests - a differential lock at all. Sensors monitor wheel speeds, and if one is rotating substantially faster than the other (i.e. slipping) the EDL system momentarily brakes it. This effectively transfers all the power to the other wheel.

Viscous coupling: invented by British firm Ferguson Formula Developments (FF), the brainchild of Tony Rolt and Freddy Dixon. Silicone liquid in a casing. Increased slip will lead to increase in the liquid's viscosity, thus locking up the coupling. Used by Subaru in conjunction with a regular center diff, so only as a locking device, as opposed to the syncro system, in which it was used as the center diff itself, creating a part-time system. The main problem with VC locks is that they work by sensing rotational differences. Thus they risk not allowing the wheels to run free and seperately under braking. You can see that the integration of ABS, which is relying on precisely that characteristic, has been an engineer's nightmare. The syncro system was simply disconnected during braking. Others reduced the viscosity of the fluid, but this rendered the system less effective, though good enough for 4WD performance road cars. It is much cheaper than torsen, and that's where its main attraction lies. Is found in some form or another in many 4WD cars, Subaru its foremost exponent.

Torsen: invented by American firm Gleason Corp. Stands for TORque SENsing differential. Mechanical device of worm gears and a worm wheel that will split torque 50/50 in a no-slip situation. When one axle slips, the gears will send more torque to the axle with most grip, thus working in the opposite way of a conventional diff. Locking is instantaneous because it's a fully mechanical device. The gears work by sensing differences in torque instead of differences in rotation. This means it will prevent wheelspin instead of reacting and curing it. Also, it won't inadvertently lock under braking, as it will only lock under power. So torsen had all the advantages of the VC but none of its disadvantages. Not only used as a center or rear differential, but also as a "trick" LSD for a sporting FWD car such as the Honda Integra Type-R.

Haldex: developed by Swedish firm Haldex. Electronically controlled multi-plate clutch. Part-time, but fully automatic solution, directing torque to the rear axle when slip occurs. Compared to syncro, it negates the need for an extra clutch to disconnect the system under braking, so it's much simpler and lighter. Acts within 1/8 of a wheel rotation. Electronics control the precise distribution of torque split. Easy integration with ABS - in fact, ABS is an integral part of the system.

A similar clutch concept using ABS sensors can be seen on 4WD cars with a RWD bias. The original Mercedes 4matic system used a clutch to send power forward, as does the system in the Nissan Skyline GTR (with a no-slip 30/70 split). A computer-controlled center clutch is also the basis for most 4WD cars with an automatic transmission, such as all Subaru auto' cars and the auto' Audi A8/V8. The Honda CR-V has a part-time clutch system as well.

Porsche's Allrad system on the 959 version of the 911 is the most sophisticated variant of the center clutch concept, allowing for variable (instead of fixed) torque split under no-slip conditions, shifting between 20/80 and 40/60, depending on acceleration and straight lining of the car. This was followed by the 964 system, which went back to fixed torque split in no-slip conditions but added a clever computer-controlled lockable rear diff to counter the 911's natural oversteer. Here, the 4WD system wasn't introduced for better traction - a RWD 911 gets off the line pretty good! - but to wipe out the dangerous oversteer that more learned drivers call fun. For the Carrera 4 versions of the 993 and 996 guises of the 911 Porsche went back to a simple VC center diff while retaining the trick rear diff and adding some ESP-style car-balancing computer tweaks. This is a technologically less advanced system than the second Allrad generation.

Finally, the all-electronic 4WD - with an open center diff - has found its way into SUVs like the Mercedes M-class, equating to something like "four-wheel traction control". This is a very simple and cost-cutting system placing excessive demands on the brakes.

The electronic differential lock (EDL) employed by VAG is not - as the name suggests - a differential lock at all. Sensors monitor wheel speeds, and if one is rotating substantially faster than the other (i.e. slipping) the EDL system momentarily brakes it. This effectively transfers all the power to the other wheel.

The main problem with VC locks is that they work by sensing rotational differences. Thus they risk not allowing the wheels to run free and seperately under braking. You can see that the integration of ABS, --- ca de altfel si ESP --- which is relying on precisely that characteristic, has been an engineer's nightmare. The syncro system was simply disconnected during braking.

Eu am ramas cu o nelamurire inurma articolului proaaspat postat de iulian :angel:
Pana acum pe threadulasta s-a zis ca Audi are torsen central si torsen spate cu EDL fata. Acum apare doar torsen central si 2 EDLuri..Pana la coada cum e treaba??

The BMW xDrive, now standard on the X5 and the new X3, can deliver
100% torque shift in 0.1 s, and there is no fixed torque distribution. So in the zero-traction situation described above, the rear axle does not spin and the entire engine torque is delivered to the front axle.

100% variabil

Pai Edmunds zice ca au LSD pe spate si EDL pe fatza. BMW-urile au EDL pe ambele puntzi.

masinile Subaru WRC ( care nu sunt produse comercial dar sunt cele care au dominat WRC in ultimii 5-10 ani si au adus renumele firmei) folosesc diferentiale centrale Torsen.

Finally, a rear differential temperature sensor is used so that if the rear differential overheats, the centre differential will unlock. During extended periods of driving aggressively with the centre differential locked, the load on the drivetrain can cause differentials to overheat, so the rear axle temperature is monitored as a safety factor.

indiferent de cele de mai sus parerea mea ramane ca Legacy GT ( si cu atat mai mult Spec este superior oricarui A4 quattro, exceptie fiind numai S4, dar care la 50k este intr-o cu totul alta liga de pret.

Noile upgrade-uri la Legacy GT spec B risipesc orice urma de indoiala. singurul element pe care Audi il pastreaza in avantaj este cel de lux interior desi si acolo spec B mai micsoreaza din decalaj. designul nu-l pun la socoteala desi o majoritate ar inclina ca este mai reusit la Audi.

In rest tren motor, suspensii, frane si performante sunt de partea Legacy-ului... daca mai asteptam un an as fi luat poate un GT spec B... mie mi se pare o masina superba... a true BMW 330i killer

he spec.B won the autocross outright, finished second in the slalom while it tied for fourth around the skidpad. The Subie shows initial, rather early understeer, but because the car is so light and the chassis so responsive, this can be cured by drop-throttle, or even some brake if necessary.

Bornhop called it "the sportiest of the bunch" and Swift called it "the most neutral."

If there's a knock against the A4, it's that it's too easy to drive. While it has very high limits, once it gets into an understeering mood it's not as easy to "bring it back" as some. This is very safe, but simply not as much fun as cars like the Subie and G35x that can exhibit a tail-out nature to change direction.

This is very safe, but simply not as much fun as cars like the Subie and G35x that can exhibit a tail-out nature to change direction.

Tot in testele americane, Jetta GLI castiga detasat in fata Mazdei, nu mai vorbesc de Audi A4 in fata versiunii europene a Mazdei.

TESTUL 3
Aici este vorba de versiunile europene
AUDI A6 Avant, Subaru Legacy, Skoda Octavia, BMW 530xd, Mercedes Benz E 320 CDI T, Chrysler 300C Touring

http://www.autobild.de/test/neuwagen/artik...;artikel_seite=

la 30-32k USD Legacy GT este fara indoiala masina mai buna comparativ cu A4 2.0TFSI care ar veni la aceeasi bani ( chiar daca mai subtirel dotat). am explicat de ce si testul din Motor Trend confirma: este mai rapid si in linie dreapta si pe circuit. chiar in citatul pus de tine se zice clar:



distantele de franare sunt mai bune, specB este inca mai usor decat A42.0TFSI, mai "fun to drive". nu zic ca A4 nu ar fi "fun to drive" doar ca e un "fun to drive" de alta natura decat specB si e prea scump la ce ofera in banii respectivi.

[Iulian, fara suparare, dar unul din noi nu intelege foarte bine ce scrie acolo:

1. 0-100; 0-1/4 mila - castiga Legacy indiscutabil
2. frane (atat la cald cat si la rece) - castiga A4
3. slalom - castiga A4
5... in general castiga tot A4

De unde ai inteles tu ca Legacy castiga la frane si circuit?

"The Subaru proved to be just about every editor's fastest way around the course, ahead of the second-place Audi A4 by 0.3 sec. When watching the Subie round the cones, we were struck by how much dive, squat and roll the car exhibited. But that translated into a forgiving nature, important since it doesn't have yaw or traction control. Its extremely potent engine provides tire-shredding thrust out of corners. And, if really provoked, the spec.B can rotate with drop throttle — not a usual trait for an awd'er. A few of us found that if we got the car to oversteer under braking heading into the big sweeper (see track map), it could be 4-wheel drifted under power all the way through. Fun stuff!

Iulian, imi amintesc de o alta discutie in contradictoriu de-a noastra: vis-a-vis de primul benzinar cu turbina cu geometrie variabila din lume. Eu am spus ca o sa fie Porsche 911, tu ai spus ca s-a amanat si o sa scoata Honda primul VTG. Iata ca au trecut cateva luni de la lansarea lui 911 cu noua turbina si inca nu auzim nimic de la Honda

I-as impusca pe oamenii de la marketing....

Subaru nu are ESP deoarece este incompatibil cu sistemul lor de tractiune. Pe modelele cu cutie automata au ESP. Orice masina are nevoie de ESP si constructorii, acolo unde pot, le echipeaza cu ESP (de exemplu Porsche are ESP)

Suby a reusit acest lucru abia dupa ce a inlocuit pe spate relicva aia de diferential cu vascocuplaj cu un torsen, adica in 2006.
Cand a avut astfel de probleme Porsche? Pana sa scoti o astfel de "perla" ar fi trebuit sa te uiti mai sus. Acolo scrie ca au inlocuit sistemul de pe 959 (amintit cu multe pagini mai inainte, in acest topic) cu o versiune inferioara, cu vascocuplaj, datorita unor probleme de comportament.

A doua gresala: confunzi EDL-ul cu TC (traction control). Sunt multe situri care denumesc EDL o forma de TC dar nu este acelasi lucru cu ce ai tu. La masina ta, TC se manifesta prin reducere puterii motorului si nu prin franarea rotii fara tractiune. Nu le confunda. Din acest motiv la ESP se decupleaza daca nu ai tractiune, dar in cazul EDL-ului nu este acelasi lucru, nu se dezactiveaza nimic...

Traction control, optional for all Venture
models, automatically activates if wheels
should spin on slick surfaces. A sensor
detects the spinning and automatically
applies the brakes while retarding fuel
flow to the engine, slowing and stabilizing
the vehicle to provide traction.

TRACTION CONTROL
Optional on Venture models with the
optional LS trim package, traction control
provides increased control during takeoff on
slippery surfaces or while driving. The system
uses electronic controls to reduce engine
power output and to selectively apply the
brakes to prevent excessive front wheel spin
on slippery road surfaces.
• The system is a powertrain management
system, controlling slippage by controlling
powertrain torque.
• When drive-wheel spin exceeds a predetermined
limit, the system will reduce engine
power by cutting off fuel delivery to a
sequence of cylinders. If this does not control
the traction loss, the system will apply
the brake to the spinning wheel to limit
its speed.
• The PCM also reduces power by retarding
the spark timing.
• Traction control is available in both forward
and reverse. It can be turned on/off
via a control on the instrument panel

Citesc comentariile tale si ma uimesti. Nu am de gind sa imi pierd vremea cu tine prea mult...dar dupa ce ai criticat un an de zile viscocuplajul din diferentzialul central acum faci o alta afirmatzie contradictorie.




Nu mi-e clar care diferentzial CREZI TU ca l-au schimbat...dar sa stii ca pe centru are in continuare visco-cuplu si pe spate Torsen.

Mai Valentine, tu ai o suferintza ascunsa...

Din audi nu iese fum atunci cand patineaza rotile fata pentru ca au gasit o solutie similara cu cea gasita de Subaru. Cand se incing franele le decupleaza pentru a se raci. :wave:


De data asta ce n-ai mai priceput?

P.S. Fanatic, i-ai omis pe cei de la Porsche (ai naibii boxeristi ) . Sa nu-mi spui ca-ti mai sunt simpatici acum dupa ce ai aflat ca folosesc EDL-ul

desi nu stiu daca mai mult de 10% din posesorii de masini integrale stiu ce hram poarta diferentialele lor

pacat ca va opreste distanta asta, ati fi fost tare simpatici la o terasa sporovaind pe tema cuplajelor astea vascoase :angel: