Tractiunea 4x4 La Octavia 2

[2.0MPI]

Poate s-am mai discutat, dar eu nu am gasit unde....

Inteleg ca are tractiune 90% fata iar diferentialul Haldex (un fel de ambreiaj) cupleaza mai mult spatele spatele cand fata pierde aderenta. Dar cat trimite maxim la spate? Si in ce timp reactioneaza?

Cum se repartizeaza tractiunea pe acceasi punte (fata sau spate)? Sunt diferentialele de pe punti tip LSD?

In final, daca raman cu cate o roata de pe fiecare punte fara tractiune, mai pleaca masina?

Poate face cineva comparatie cu sistemele Quattro si cel de la Subaru (asta din urma parca are 2 sau 3 LSD-uri)?

Sa stiu pe ce ma bazez cand situatia devine roz!

[72THX]

Din cate am stiu eu (sper sa nu fie eronat) ca ai tractiune fata 100% ier cand simte ea trece la 50 - 50.

Din spusele unui coleg (care a condus o Octi2 4x4) nu apuca roata sa faca o jumatate de tura si a intrat 4x4.

[DORU_14]

Distributia intre punti este 90-10 implicit. In caz de aderenta slaba, spatele intra repede si f puternic, 50-50 dar sunt si momente in care trage mai mult decat fata. Era un material pe un site care explica acest lucru, pacat ca nu-mi mai amintesc unde l-am citit (era unul cehesc daca nu ma insel).

[2.0MPI]

Dar pe punti ce diferentiale are? Daca o roata este fara aderenta, cealalta se mai invarte?

Am avut cateva experienta contradictorii:

1. la trecerea oblica a unui sant am incrucisat puntile in asa hal incat au ramas doua roti (diametral opuse) in aer, cate una de pe fiecare punte. Masina s-a transformat intr-un balansoar :D ! ma gandeam ca nu mai plec dar, surpriza: masina a plecat fara cea mai mica ezitare. Intamplarea asta mi-a dat sperante, ca am LSD + chestii electronice destepte dar......

2. in doua randuri, la urcare, am ramas pe loc cu rotile patinand. Sunt sigur ca patinau cel mult 2 roti, poate chiar una (pe fata). In ambele cazuri rampele erau decente, nu credeam ca am probleme. Dupa ce i-am dat putin elan le-a urcat fara probleme (probabil ca s-a destepta vre-un micro-cip ceva :wacko: ).

Pacat ca cei de la Skoda nu au inclus in manualul masini o descriere a sistemului 4x4 si nici dealerul nu stie mai mult decat de diferentialul Haldex si de 90;10 si 50:50.

Probabil ca pe zapada o ma lamuresc mai bine .

[72THX]

Hai ca am gasit eu ceva pe net.

Link:

http://www.haldex-traction.com/technical_i...n_qualities.htm

http://images2.rdefined.com/v/GabeDibble/t...Layout.jpg.html

[DORU_14]

" With the OCTAVIA 4 x 4, SKODA is enlarging its production range with a vehicle offering the most modern permanent all-wheel drive technology.

Classical all-wheel drive concepts - still found today in a large number of off-road vehicles - in many cases make use of a rigid connection which is engaged by means of a handshift. A new technical feature for permanent allwheel drive with an additional connection at the rigid through-drive to the rear, operated independently of the driver, was the viscous coupling, as fitted for example to the VW syncro.

This was in the position only to detect wheel slip, but not the cause of it. To ensure reliable braking in such cases, both axles had to be decoupled by means of a freewheel. When reversing, the axles were again connected by means of a lock.

A significant advance in modern all-wheel technology has been achieved with the development of the Haldex coupling.

The Haldex coupling can be controlled.A processor analyses additional information during the control cycle. It is no longer the wheel slip alone which is decisive for the

distribution of the tractive forces, but also the dynamic state of the vehicle.

The processor accesses the ABS wheel speed sensors and the engine management system (accelerator pedal signal) through the CANBUS.

These data provide the processor with the information which is required regarding vehicle speed, cornering, deceleration or acceleration, and enables it to react optimally

to the particular situation.

Advantages of the Haldex coupling

– Permanent all-wheel drive with electronically controlled multi-plate coupling

– Front-wheel drive characteristics

– Rapid response (power transmission)

– Instant decoupling of both axles

– No stresses in the drive train when parking and manoeuvring

– No restrictions when towing vehicle with front wheels raised

– Can be fully combined with wheel slip control systems such as ABS, EDL, TCS, EBD and ESP

– Possibility of simple test of brakes and performance on roller dynamometer "