For those who want to understand what corner weighting is about: http://www.grmotorsports.com/cornerweight.html

http://www.hadamotorsport.com/tech/howto/c...ghts/index.html

 

Chris, the effect of having a pre-loaded swaybar connected while cross-balancing is the same as the effect of having one spring perch higher than the others.

There is a fixed difference between the height of the right and left corners for which the swaybar is not exerting a force. If the body of the car is not at exactly that angle, the swaybar compresses the suspension on one side and stretches the suspension on the other side (just on the end of the car where it is attached). The diagonal which includes the compressed corner loses weight, and the diagonal which includes the stretched corner gains that weight.

The total weights for each side of the car are independent of the suspension.

The total weights for each end of the car are independent of the suspension.

The cross-balance is dependent on pre-loads, whether they are on the springs, or on the swaybars.

A swaybar with no preload will have no effect, but as soon as you start adjusting the corner weights/heights, the swaybar is no longer unloaded.

 

Guys I am not stupid.. this is what I posted:
1) The weight on each corner is exactly what the scale says.
2) A sway bar will not make that much difference.
3) Of course you would disconnect the sway bar before adjusting.

What did I say that required so much explanation?.. Obviously if the car is so jacked up with a swaybar preloaded off to one side (which is NOT the recommended way to balance the corners, possible with the stock endlinks, or normal that I know) it could change the cars stance slightly and therefore the balance.. but dammit.. the weight on each corner is exactly what the scale says!

 

The weight on each corner is of course exactly what the scale says. But if there is a preload on the swaybar, then disconnecting the swaybar will change the weight on that corner. Call the effect slight if you want, but the very idea of cross-balancing is to eliminate such slight effects! The effect of swaybar preload is the same order of magnitude as spring perch height, and spring perch height is what you're adjusting.

The fact that the side-side balance and front-rear balance are not affected by suspension does not mean that the balance between the two diagonals (RF+LR and LF+RR), or the weights on each specific corner are not affected. The cross balance is the only thing that's affected, and that's what you're trying to adjust when measuring the corner weights.

Example:

100 100
100 100

90 110
110 90

In both cases, the right-left and front-rear balances are 50/50. However, all four corner weights have changed. This type of difference could be due to a swaybar preload (although I doubt you'll see this magnitude of an effect due to a swaybar orspring mismatches in real life).

 

Welp, it's obvious to me that I need to lose about 100 lbs to get the car's left and rear balance to 50/50.

Nah - I'll take the penalty...

 

After adjusting spring perch height, or using the height adjustment as on a Mugen N-0, wouldn't reconnecting nonadjustable sway bar endlinks upset the acheived weights somewhat?

 

Yep, that's why people use adjustable endlinks. I guess if you're stuck with non-adjustable you should leave 'em connected, or maybe just not worry about cross-balancing in the first place. If you've gotta do it that way, try to eliminate all the free play in the swaybar by making sure everything is tight and using stiff bushings.

Adjustable endlinks are what -- $60 or so? How much does it cost you to get cross-balancing done?

 

[QUOTE]Originally posted by Orthonormal
[B]Yep, that's why people use adjustable endlinks. Adjustable endlinks are what -- $60 or so?

 

My latest with me in the car, 4/5 tanks of gas:

740 699
742 700

 

LF: 676 RF: 681
LR: 650 RR: 647

2654 lbs full tank of gas and without me in it...