Shark_V8

Well that leads into the next question I had about the A8 rear diff. Is that A8 an open diff rear?

It feels like my V70R - Haldex system. As the R rocked through the corner, torque was sent rearward it was awesome. The 2006 car felt like it had like an F1 active susp/driveline, very cool. The 2004 R not so much, more conventional ride, as its Canbus and programming were older rev and 1/2 the speed.

'93 Audi V8Q had the torsen rear diff, electric clutch center. Monster grip off the line. But yes strange behavior coming off say low curbs in turns. Porsche 928GTS has PSD, or clutch rear diff. Least noticeable of all of them, since the car haS a ton of grip anyway.

One last try here. Lets move axle spacing from X to 0. Let's take the front axle of the A8 and bring the two front tires together ala the Delta Wing. Now turn the car right, and what will happen? The right rear wheel will start to lift off, like a kid's tricycle, leaving one rear tire to fend for itself. In fact it will keep lifting until airborne and if the outboard rear doesn't slide the car will flip due to improper weight distribution. Is this understeer?? Hell NOPE, it's classified as oversteer.

Now let's take the car and move the rear axle to 0, both rear tires together. Turn right, and what will happen? The inside front right will start to lift off, leaving one tire to fend for itself, yielding understeer. Got it?


OK mixed bag from Kraus Racing:

To CORRECT Oversteer (ie take out oversteer & tighten up back-end)

Lower front tire pressure. --BACKWARDS? INCREASES CONTACT PATCH & HEAT = GRIP.
Raise rear tire pressure. -- REDUCES CONTACT PATCH & HEAT SEEMS BACKWARDS....
Stiffen front shocks. -- REDUCES FRONT DIVE
Soften rear shocks. -- INCREASES REAR COMPLIANCE
Raise front end. -- WEIGHT TO REAR
Lower rear end. -- WEIGHT TO REAR
Reduce rear track --OF COURSE
Install taller front tires. -- WEIGHT TO REAR
Install shorter rear tires. -- WEIGHT TO REAR
Install narrower front tires. -- LESS FRONT GRIP
Install wider rear tires. -- MORE REAR GRIP
Stiffen front sway bar. -- LIFT INSIDE FRONT WHEN OUTSIDE FRONT IS LOADED (KEEPS AXLE MORE LEVEL)
Soften rear sway bar. -- KEEPS TIRES IN CONTACT DURING BODY ROLL
More front toe in. -- NOT SURE THIS IS CORRECT AS TOE-IN WOULD INCREASES FRONT BITE, INCREASING OVERSTEER. OR DOES IT CAUSE MORE SLIP DUE TO SIDE SCRUBBING
Increase rear toe in. -- AS PER WEISSACH AXLE? HAS TO BE ONE OR OTHER NOT BOTH
Reduce front negative camber.-- CORRECT MORE SLIP LESS BITE
Reduce positive caster.-- OK
Stiffen front springs.-- YES LESS WEIGHT TRANSFER TO FRONT
Soften rear springs. -- AS ABOVE
May need more rear suspension travel. OK TO MAINTAIN CONTACT
Install wider rear wheels. -- SURE
Use harder front compound if possible. -- INCREASE SLIP (DULL FRONT EDGES OF SKI)
Use softer rear compound if possible. -- INCREASE GRIP( SHARPEN REAR EDGES OF SKI)
Add weight to front of vehicle. -- OK
Remove weight from rear of vehicle. -- OK EG SPARE TIRE!!
High Speed. Increase rear wing down-force. -- ADD REAR GRIP, ALSO REDUCE FRONT WING
Too much rear brake. -- BRAKE FORCE + CORNERING INCREASES TIRE SLIP

mishar

I know, but that is impossible.

That just complete the story. In order to sell cheep concept and keep FWD in the picture, they spent tons of money on senseless additions like Thorsen and ridiculously complicated sport rear differential. Only thing that saved, actually launched Audi, was other guys late development of AWD.

mishar

I enjoy reading your posts like reading poetry. I just don't understand most of it.