The other German car company marketers stress ideal weight distribution and superb balence. I am curiuous how much this really matters in the real world and on the track? Please help me understand what it all means. Thank you

 

both braking and acceleration. Ideally cars should be a 50/50 split in weight. The more neutral a car is in handling the easier it is for a skilled driver to utilize its potential traction and power effectively. THis is critical on the track and equally important on the street. Often times by effectively corner weighting a car you can manipulate the vehicles weights and increase positive aspects of handling or try to decrease negative aspects as well. but keep in mind suspension both in type and geometry as well as tire type and pressures utilized can also greatly effect hanndling....the key thing is to have a full package where everything is tuned to either the track conditions or your particular driving style.... theres a multitude of different racing events that all require different settings....sorry to many variables to give you a full answer.

 

Well said BuLLit....

 

Thanks ).... lol now all I need is some good coilovers and a scale.

 

It's deeper when you consider polar moment of inertia (low or high).

 

Actually (4) scales!!!!!

 

especially during cornering. To do this you need approximately equal front and rear weight distribution (so-called 50-50 or 50% front and rear). We are starting with a 60-40 or 63-37 or so vehicle platform in the TT, so we make the front tires work very hard during cornering, and then ask them to accelerate the car also. 2 strikes.

That heavily overworks the fronts before the rears resulting in "push" or understeer as we approach the limit of adhesion. By adding quattro we take some of the drive work off the fronts and make the rears work harder (and add a little weight to the rear also). This helps balance the work we are asking the tires to do.

Another problem with front-heavy cars with the engine at or ahead of the front wheel centerline (Audi) is polar moment of inertia, or simply the cars reluctance to start a turn, and its reluctance to stop the turn. The standard analogy is the barbell on a long shaft supported on your shoulders: it's more difficult to start spinning your body and to stop than if you had the same amount of weight strapped to your belt (or were built like me).

If one had to make one end heavier, a rear-drive vehicle with rear weight bias (Porsche 911) lets the fronts do lots of the cornering ewhile letting the rears mainly put power to the ground.
With high power-to-weight ratios (F1, Cart, etc) weight is biased to the rear and rear has larger tires mainly to get the power down.

Balancing by adjusting corner weights on a street car can have only a minor effect. You can't move weight from the front to the back by adjusting spring heights, but only by physically moving parts of the car or ballast. You can transfer weight diagonally, but TOTAL front/rear and TOTAL left/right won't change.

Some folks won't believe this. One exception: if you raised the front 4 inches and dropped the rear 4 inches, you could move about 25 lbs from the front to the rear on a 30000 lb TT. A 1 inch rake (instead of 8) would reduce that to about 3 lbs., and you'd be raked the wrong way for aero.

Yes, all else being equal (which it never is), balanced is better than massively front heavy.

BTW, during hard braking, TT has about 80+% of its weight on fronts while a 40-60 Porsche 911 is almost 50-50 or just slightly front heavy. That explains why 911's have big brakes all around, and why TT doesn't.

My $.02

 

Yep, high polar gives the TT (and most Audis) a stable initial "feel".