Bob

sorry - "known quantity".

pdw

It's completely possible you're right and I don't know what I'm talking about. However, I have noticed while doing donuts in a parking lot, if the car was already plowing it would plow more when given gas. Also, I thought Torsens sent the torque to the end that was harder to twist. In the case of an understeering car, it seems like this would be the front.

I really don't want to rehash the Qlist and in real world situations, I'm sure none of this matters.

Josh Pinkert

Erik,

> The qlist is infected with people with gen1-3
> q's overcompensating by saying that the gen4 q
> is somehow dangerous.

I was part of one of the discussions of the application of a torsen differential as a center differential. 1st...the original complaint surfaced concerning Gen 3 quattros (which uses a torsen center diff as well, appearing in the Audi 90 from '88-on and the Audi 5000 from '88/'89-on). There were experienced racers who were trying to explain the dynamics that occurred while racing Gen 3 equipped 5000/100/200 Audis. The 'spider bite' theory was applied to the A4 (gen IV quattro) as well considering it has the same basic design.

>Third, the reason why it doesn't happen is that
>the weight transfer coming out of the corner is
>either nearly neutral (with race springs) or on
>the rear tires (stock springs). Torsen transfer
>to the end with MORE traction, in this case the
>ear, (never the front). If your weight is on >the 'front you will oversteer to the outside IN
>ANY CAR.

First, you don't seem to understand the fundamental operation of the torsen. I don't care to dig up the Gleason schematics or technical documentation that people posted. But after reading and examining those (including punching numbers into mathematical formulas that describe how a torsen will act) it was determined that 1) the torsen doesn't/can't freewheel on deceleration, although it doesn't adversely affect braking in a straight line, 2) torsen DOES NOT react based on torque...it reacts based on differences in output axle speeds...just like VC diffs do (except usually quicker).

Second, you ignore the rest of the corner. What the Q-list described was a situation where the torsen hunted...causing the attitude of the car to change from oversteer to understeer and back to oversteer. When oversteering, the rear wheels of the car are often turning slower than the fronts. Thus fooling torsen.

The general concensus is that the wheelbase of the car determines how likely the car will exhibit this behavior. Long wheelbase = more likely. That's why so many 5000/100/200 owners have seen it. But there are/were reports of 90 and A4 drivers encountering spider bite.

Just because you haven't seen it in person doesn't mean it can't happen or doesn't exist.

- Josh
- '98 A4q 2.8
- '72 911T