Center Differential Upgrades for B5 rallycross car

[enginerd]

I am looking for center and rear differential updates for the Audi quattro system in my 2001 A4.
I race the car in SCCA rallycross competition and having just a torsen center differential is a disadvantage in low grip ice/snow events. Typically the car swaps from severe understeer to severe oversteer and back and forth with the torsen just spinning one end like crazy.

I noticed in 2010 there were some updates to the center differential

A new " With the new "Crown Gear" center differential, up to 70% of the torque can be applied to the front wheels while up to 85% can be applied to the rear wheels if necessary. The net result of this advance in quattro is the ability of the vehicle electronics to fully manage the vehicle dynamics in all traction situations, whether in cornering, acceleration or braking or in any combination of these."

I have run with locked differentials in the coupe quattro's and the understeer was pretty bad. Rather than go to a locking differential I was thinking this might be an option.

Does anyone have any details if this swap is possible? Does the new center diff require a controller? like a haldex unit?

Would this diff, or complete trans fit in a B5 A4? would the ratio's match my existing rear end- or could I swap the whole driver train in? I haven't really kept up to speed on the new audi's so I am not sure what is compatible anymore.

As far as the rear diff - I have machined a "phantom grip" diff insert with die springs to add 400 lbs preload to the spider gears, but it's far from a real lsd. are there any affordable options out there? OEM swaps?

PS - my co driver and I kick the crap out of the subaru's in awd modified class !!!!

[boost is better]

Stasis high bias diffs. click on learn more at the bottom.http://www.stasisengineering.com/pro...late-1996-2001

[TBT-Syncro]

Stasis high bias diffs. click on learn more at the bottom.http://www.stasisengineering.com/pro...late-1996-2001

i dont believe the OP is looking for a center diff, but is looking for an actual rear-end differential.

does Quaife or Peloquin have any options?

[boost is better]

He asked for center and rear here is a link to for quaife rear. http://www.quaife.co.uk/shop/products/qdf4q-0 also there is a rear lsd option http://www.034motorsport.com/chassis...i-p-17562.html

[enginerd]

thanks for the info guys. The stasis rear diff is way out of the budget. 2700 is just nuts for the type of racing I am running in.

The center diff looks like a stock oe diff that they change out the teflon coated washers for carbon steel washers and a higher bias ratio. If I am wrong please correct me.

I can see how a higher bias ratio would be good for pavement, but for the mud/ice i am looking for something with more of a locking feature, clutches. A high bias ratio wont help if ice = no grip in the rear. 0 x 10 = zero so its not going to help much.

I am most interested in learning if the newer a4 trans/rear has any benefits and if it can be swapped into the older cars. I can get junkyard trans/diff for half the price of the stasis setup.