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Audi
Audi 80/90 quattro, Audi Quattro, Audi UrQuattro 1981-1987 - First quattro generation. Full-time all wheel drive with free
differentials. Manually locking
(by 2 rotating switches on the console) rear and center differentials.
Figure: Audi 80 B3 quattro
Figure: Audi 100 C3(?) quattro
Figure: Audi Quattro
Figure: quattro I transmission. On the top picture: center differential (5), center differential locking fork shaft (6), differential locking actuator (7)
Figure: Audi 100 quattro rear differential
Figure: Audi 100 quattro rear differential locking mechanism (arrow)
Figure: Audi 100 quattro center differential locking mechanism
Audi 80/90/100/200/S4 quattro 1987-1994 -
quattro II. Full-time all wheel drive. Torsen center differential
with automatic distribution of torque between front and rear axles.
Manually activated (electro-pneumatic system) rear locking differential
which automatically unlocks when speed exceeds 25 km/h.
Figure: Audi 80 B4 quattro
Figure: quattro II transmission with TorSen center differential
Figure: Audi 100 rear differential and differential lock fork(13)
Figure: Audi 100 rear differential locking vacuum pipes
Audi V8 Automatic 1988-1994 - quattro
III - Full-time all wheel drive. Torque distribution via electronically controlled multi-plate
hydraulic transfer clutch in the center. Torsen differential in
the rear axle. Quattro was for the first time used with automatic
transmission. The gearbox was the source for high pressure oil,
that was used to activate the clutch.
Audi A4/A6(C4)/A6(C5)/A8/S4/S6/Allroad quattro 1994-2007, S4/S6 quattro 1994-2005 - quattro IV - Full-time all wheel drive. Torsen center differential.
Electronic traction control (EDL) on front and rear axles that applies
brakes to spinning wheels, which has effect of locking front and
rear differentials. Works at speeds up to 40 kph (25mph). On more
powerful versions S4/S6 - up to 80 kph (50mph). A8 uses EDL and
ASR, which reduces engine output. It is almost impossible to lose
traction with this system under any circumstances, except if one of the axles is raised in the air.
Audi Allroad can feature low gearing (optional).
Figure: Audi A4 B6 quattro
Audi RS4 B7 manual/Q7 2005-..., S4 B7 manual 2006-..., A5 2006-..., A6 2006-...(verify), all A4 B8 2007-... - quattro V. Full-time all wheel drive. Torsen type III planetary type differential with a 40/60 front/rear split for improved handling.
Audi RS5 (2011-...) - quattro VI. Full-time all wheel drive. Crown gear differential with a 40/60 front/rear split.
Audi A3/S3 quattro (1998-2003) - Haldex Generation Iautomatic all wheel drive system - electronically controlled Haldex multi-plate hydraulic clutch, located near the rear differential. Normally front wheel drive vehicle. It detects the need of all wheel drive at 1/8 of the wheel spin and transfers up to 100% of torque to the rear axle.
Yes - George thanks for the correction. It is a max of 65/35 f/r. As far as weight distribution....they 4cylinder (like the wagon) is more balanced in the sedan than the V6.
Amidat
January 10, 2010 - 02:12
Subject:
I see you updated the page - but you didn't include a diagram for the B8 chassis. I do believe that generally the weight distribution front/rear is now 54/46.
Also as you indicated - the new front/rear torque ratio is a default 40:60 but you left out the variables. If I'm not mistaken (from a rep at Audi) it can vary depending on conditions between 70:30 and 15:85
Reply to Amidat
awd.ee
January 10, 2010 - 11:42
Subject: B5
Do all B8's have the quattro V system with 40:60 torque distribution, not just the S-versions?
Reply to Amidat
Amidat
January 10, 2010 - 23:04
Subject:
awd.ee - yes they do. Even a normal A4 2.0T has it.
Reply to Amidat
George
January 11, 2010 - 02:58
Subject:
The torsen3 center differential can vary +/- 25% from 40/60 nominal, 15/85 while the front are overrunning the rear, 65/35 while on rear overrun.
I have seen 54/46 on the A4 wagon [Avant] with manual transmission, and 56/44 in the sedan with V6 & automatic.