Front to Rear ratio

[gtsingh91]

does anybody know the quattro front to rear wheel power ratio on an 05 A4 1.8TQM? thanks

[Exanimas]

Pretty sure it's 40 front / 60 rear. 99% sure.

Edit: 99% sure, 100% wrong.

[A4_Mike]

I thought the new B8 platform is using a 40/60 F/R ratio whereas the B5/B6/B7 platforms use a 50/50 F/R ratio?

Confirmed via wikipedia - 50:50 (F:R).

[F16HTON]

There is no true ratio...bias is based upon the specific load that the torsen sees.

[NyteEscape]

in general 50:50. when need be, up to 66% of power can be transferred to whichever side has more traction.

[vc1492a]

I thought the new B8 platform is using a 40/60 F/R ratio whereas the B5/B6/B7 platforms use a 50/50 F/R ratio?

Confirmed via wikipedia - 50:50 (F:R).

X2

[FORCE_FED_DUB]

in general 50:50. when need be, up to 66% of power can be transferred to whichever side has more traction.

x2. torque bias is constantly changing. acceleration: up to 66.6% rear, deceleration: up to 66.6% front, constant speed ~50/50

[F16HTON]

There is no true ratio...bias is based upon the specific load that the torsen sees.

^^^^

[ThatGuyAlex]

Pretty sure it's 40 front / 60 rear. 99% sure.

If that was the split you could drift the car in the wet super good. But its not.

Thank god you did not put your life on that!

[downhillracer]

Like 400HPA4 says.. it is based on the load that the torsen (center diff ) sees. Its not 50/50 or 60/40 it is constantly changing

[Charlescrs6]

Is it true the R8 is something like 70/30?

[Pothole]

Is it true the R8 is something like 70/30?

i heard 80/20, but its something like that because it can do tight doughnuts all day on dry pavement

[AudiA4_20T]

i heard 80/20, but its something like that because it can do tight doughnuts all day on dry pavement

yea, my friends STI can rip doughnuts all day with 80/20

[F16HTON]

Donuts are no big deal...they are pretty hard on the steering rack though.

[FORCE_FED_DUB]

Like 400HPA4 says.. it is based on the load that the torsen (center diff ) sees. Its not 50/50 or 60/40 it is constantly changing

but it is limited by the center differential's built in biasing ratio. no more than 2/3 of the engine's torque can be transmitted to either end of the car. torque bias is based on load and traction. when you accelerate weight transfers to the rear, the rear has more traction and load capability, so up to 2/3 of the engines torque goes there. opposite is true when you decelerate; front has more traction and load on it, so more deceleration torque is transferred to the front(not really noticed).

a lot more goes into road holding characteristics (doughnuts) than torque bias (power, suspension, tires, weight distribution, etc.)

[F16HTON]

The only thing you need for donuts is more power than traction...

This was done on dry pavement with a stock bias center diff. http://www.youtube.com/watch?v=_gIGFY7KgO0

[Pothole]

mmmmmmmmmmm i do like doughnuts

[Plasticar]

Yes, it self-adjusts to provide power to the best axle, that is what the torsen center dif does. It means TORque SENsing. The default ratio, however, IS 50/50 for all A4/5/6/8 cars up to the most recent redesigns B8/C6.5/D3.5 I believe are the designations. The R8 is probably different, and the TT and A3 uses the Haldex system based on FWD, so it is mostly or all FWD in normal and sends some to the back as needed.

[Exanimas]

If that was the split you could drift the car in the wet super good. But its not.

Thank god you did not put your life on that!

My post was edited for clarity.