Do you see the scales under each wheel? It was done.

 

Yes I do. I am sure it was done. I'm just saying
that 'corner balance' means LEFT FRONT =XXXlbs,
RIGHT FRONT = YYYlbs, LEFT REAR = ZZZlbs, and
RIGHT REAR = XYZlbs. I hope they kept the notes
on where you ended up, or at least the cross weight
differences. A short-hand for a corner balance target
is that LF + RR needs to be as close to RF + LR as
possible. My last one was to within 5 lbs. If there is
any significant difference, the car will be less stable.
One important step in a serious corner balance is that
it must be done with each sway bar detached at one
end, and ideally with the driver weight in the car, so
when they re-attach the sway bar there is no preload
under the conditions you'll be driving.
Joe

 

In my conversations with Robert he most certainly does use ballast for the driver and likes to do the setup with a half tank of gas in the car.

 

whats the price for the wheel and tire set up that you have on the car?

 

Mitchell Sack - you can call me at the number below for a quote.

 

It is my understanding, and it has been confirmed on this thread, that corner weighting (balancing) is to be done before alignment is done. I have heard others say that it is the opposite, in that you first align and then corner balance. Am I correct with A. corner balance and B. align?

 

I think you want to set ride height first, corner balance second then 4 wheel align with a slightly more aggressive than stock alignment and you should be on rails.

 

Joe, this was all done. The corner balance results is done free hand on my own worksheet seperate from the Biessbarth printouts. I don't have a printer hooked up to my scales. I will post the sheet tomorrow. I was able to achieve a perfect balance on Dan's car with less than 1% difference on the cross weight. His front to rear was a typical 40% front and 60% rear.

Everything Joe has said is correct. Proper corner balance is done with operation weight with sway bars disconnected. Porsche requires the gas tank to be full but I have always done them with the tank half full. Correct hot tire pressures are very important, not factory cold pressures. Factory cold pressure are ok when only an alignment is done. If a car is equiped with ride height adjustable suspension then a corner balance should be done even if the car is never tracked. All that money spent on coilovers is wasted when they are installed with only a static height adjustment and a simple alignment. In short, a balanced car will handle the same turning right or left...neutral. Of course, there is much more involved with the dynamics of car handling...spring rates, damping, swaybars, tires, wheels, brakes, etc....

Robert

 

Neither is correct. A proper corner balance can only be done WITH a full alignment done at the same time. Every change made with the alignment effects weight on that tire which effects the contact patch. This is why a full corner balance with alignment takes so long to do correctly. On my customer's Porsche cup cars, full setup can take me as long as 8 hours to do. EVERYTHING I do or change effects something else, that is why it must be done at the same time.

Robert

 

Dan's car is mostly a street car. If the values you are talking about is the overall difference between the front right and front left camber, this was done on purpose. Our Arizona highways and local road have excessive road crown due to our Monsoon seasons for drain runoff. I run a little less negative camber of the left front and a little more negative camber on the right front to countermeasure the road crown so that the car will track straight. Anybody that has driven any late model Porsche (all 993, Boxster, all 996, 997, Cayman and Cayenne) and get a slight drift or pull to the right will know what I am talking about. Our cars are so sensistive to road crown. Sometimes I will do the same to the rear settings but to a lesser extent. Toe is always set to spec on street cars.

Robert

 

Robert

As I had mentioned, there are slight variances that are rather meaningless, I was not talking about camber but Castor for instance. Being someone who does his own alignments and corner balancing before every race, I know how irrelevant these differences are on a car with rubber bushings. I use excellent new state of the art MAHA equipment that the local dealer graciously lets me use at will (against some $$$ obviously!) By the time you put the car on the ground, many of the settings will have changed by a few minutes already, unless you have solid bushings etc..I take a couple of laps around the block and put it back on the equipment again, and start all over again. It is a royal PITA.

Taking into consideration local road specifics for the alignments is very insightful indeed. The tramlining in my car is solved by reducing toe out, but that is counterproductive for the track where I dial aggressive toe out rather.

It is good for you to chime in and clarify, the title of this thread was confusing to me, as what was posted had little to do with corner balancing. I also agree with going back and forth between alignment and corner balancing, I have to do it back and forth quite a few times before it works out as I need it.

Cheers
Jean

 

Robert, thank you very much for taking your time to speak about your
best practices! I have a question. Do you ever target the corner weights
to be LF/LR=RF/RR? The reason I ask is because for autocross (what I do),
cornering is paramount, even to the possible trading off of some braking
or acceleration. Our AWD cars can never lose much acceleration traction,
but ideal braking config (in the dry) would tend toward LF=RF, but I would
likely accept a little more difference in my front weights, even beyond the
natural balance of LF+RR=RF+LR, if it got me significantly closer to LF/LR=
RF/RR. This is because everything we do in the car; spring rates, equal shock
valvings and settings, and for track, equal alignment settings, all these tacitly
assume the car will behave the same when turning left or right. It seems to
me that if a car is 60/40 on the left side and 55/45 on the right side, then if
we tune the car to be neutral for left turns, it will will never be precisely
neutral for right turns. For me, there was fortunately not too much difference
between the natural neutral corner weights and my cornering optimization, and
in fact the slight bias made the fronts more equal for better max braking, at the
cost of a little more imbalance of the two rear wheels.
thanks again,
Joe

 

The Beisbarth aligner is one of the best machines on the market if not the best machine period.

We were one of the first shops in the USA to use this machine and partner with Beisbarth many years ago.


Just out of curiosity how did they corner balance a car with the alignment heads attached to the cars wheels? That has got to be another 10 lbs per corner?



Secondly I see they are using conventional mounting heads... Is there a reason for that?

We have the Porsche Factory version of the Beisbarth aligner and it offers a mounting head that attaches to hub.. Which gives the most accurate reading..

Not saying that this is inaccurate... Just curious..


I do want to clarify that the Beisbarth machine is light years ahead of any BEAR, Hunter or other conventional aligner out there.


Kudo's guys!

 

I just do a little math on each corner and subtract the added weight.

I can't at this time afford the hub adapters, but very soon.

I have been using my Beissbarth Microliner since 2000 when I was with Technodynne, we where the first in AZ to have one. We have just completely upgraded all the software which required replacement of just about everything short of the alignment heads. The Beissbarth is light years ahead as mentioned, nothing even comes close. They are used by the Porsche factory for the street and race cars.

 

It never fails to amaze me on how knowledgeable Porsche owner/driver's are about there cars. Very well said Jean.

Robert