The A4 is rwd biased?

[Nor_Cal_Driver]

I searched drive bias and rear wheel drive bias and found nothing. The only reason I ask is because the base model A4 is FWD.

Since the motor is mounted long ways like a RWD car, I assume the A4 is RWD biased, is this correct?

[F16HTON]

No, it is FWD Bias, the torsen diff provides traction to the wheels that need it.

Torsen

[mook]

incorrect. the engine configuration does not declare drive wheel bias, that's done with the center diff. most AWD cars are 60/40.

[offroader1006]

yeah, most are slightly rear biased because of the straight shot to the rear axle, and that acting like a RWD car until encountering a traction loss is the idea of the system.

[mook]

Originally posted by offroader1006
yeah, most are slightly rear biased because of the straight shot to the rear axle, and that acting like a RWD car until encountering a traction loss is the idea of the system.

watchu talkin' bout, willis?

[F16HTON]

In stock conditions, the Torsen is close to a 60/40 bias, this can be corrected to close to 50/50 with shimming of the center diff. STaSIS Engineering can do this, ask Jet Jockey, he has performed this modification.

[LEDFoot]

Torsen quattro is 50/50. not 60/40.

[Daft]

Originally posted by b6quattro
In stock conditions, the Torsen is close to a 60/40 bias, this can be corrected to close to 50/50 with shimming of the center diff. STaSIS Engineering can do this, ask Jet Jockey, he has performed this modification.

The Torsen diff is 50/50. Fact. Call Torsen and check for yourself.

Yes, you can add washers to the larger end of the torsen to modify TBR but, you would effectively change the TBR under positive and negative loads.

Here's the bottom line.

There are 2 versions of the Torsen diff in Audi cars.

T-1: This model is used in MT cars only. It has been the same model since quattro was first brought to production in 1986. There was one subtle change in late 1997 where a needle bearing on the rear end was swapped in favor of a teflon inpregnated washer set. Standard ranges of TBR are: 2.5:1 - 3.5:1

T-2: This unit was added in 1995 for Audis with Automatic transmissions. Before 1995, there were no Audi cars that had both an automatic transmission and quattro. Standard TBR ranges are: 1.5:1 - 2.5:1

The hard facts of the Torsen diffs used in Audi cars:

In standard part throttle driving, the Audi A4/A6/A8 drivetrain is a 50/50 split. If you are under load via throttle, your rear wheels can receive as much as 65-70% of the engine's output. When you are in a negative load condition such as downshifting, the torsen can direct as much as 80-85% t othe front wheels. This was a requirement from Audi because you don't want your torque bias to high in the rear under deceleration. This can cause the rear wheels to drag the car into a left/right yaw and will send you off the road.

[EVIL-AUDI]

^^ Believe him ^^

[offroader1006]

with an avatar like that, you'd be crazy not to

[Greyhound Guy]

I was gonna say I swore it was 50-50. When I am straight line on the snow and hit it, I can hear/feel the power go to the back more.

And Daft, I thought you might like this, I had it on file.

[DarkkstaR]

Definately RWD bias based on driving.

Thanks to Daft for good information.

[JMG]

Daft is the man. Excellent post.

[Daft]

Originally posted by Greyhound Guy

And Daft, I thought you might like this, I had it on file.

Hehe, That's pretty cool. It reminds me of one of those giant stone heads on Easter Island.

[Nor_Cal_Driver]

Daft, you totally awnsered my question beyound doubt. Thank -You.


DarkkstaR, I agree, it does feel RWD biased when driving, much more fun the WRX's IMO.

[white fish]

makes a lot of sence
you can kinda feel it when I'm doing donuts in the snow

[aks986]

Stupid Question:
I was recentily thinking about the idea of making a rwd a4 from a quattro a4. How much work would this be? Has any one done it? Any idea of cost?
I live in Tucson, AZ and dont really need the quattro, and miss the feel of my other rwd car, plus i could deff use the extra hp to the wheels. Any insight would be great.

Shea

[mike-2ptzero]

Originally posted by aks986
Stupid Question:
I was recentily thinking about the idea of making a rwd a4 from a quattro a4. How much work would this be? Has any one done it? Any idea of cost?
I live in Tucson, AZ and dont really need the quattro, and miss the feel of my other rwd car, plus i could deff use the extra hp to the wheels. Any insight would be great.

Shea

Stand alone tuning and if you want 100% rwd you will need to install a normal rwd tranny.

[aks986]

i was just thinking that with my dads 996tt when they put it on a 2wd dyno they just disconected the drive shaft, and i understand that would be diffrent with a front engined car, but i was hoping it wouldent be all that complex. So there is no some what simple way of doing it? you couldent just disconnect some parts or make a few part replacements?

Shea

[mike-2ptzero]

Originally posted by aks986
i was just thinking that with my dads 996tt when they put it on a 2wd dyno they just disconected the drive shaft, and i understand that would be diffrent with a front engined car, but i was hoping it wouldent be all that complex. So there is no some what simple way of doing it? you couldent just disconnect some parts or make a few part replacements?

Shea

Dont think its that easy with the quattro setup. We cant dyno on a single roller and at the drags I have seen S4's break half shafts, rear diffs and the drive axle. When this happened the S4 could not drive on its own.

[offroader1006]

you would have to beef up the rear to handle 100% of the power,

find a way to disengage the center differential that puts power to all 4 axles. may just be as easy as bolting a flange where the front axle shafts go in that makes the power flow to the rear.

but then youll have to put a mock CV shaft end into the knuckle to keep the preload on the front wheel bearings. because the hub nut is what keeps the bearing loaded.