Corner balance help

[pfanning]

The rear shocks on my '06 Exige with track pack were replaced under warranty. The dealer also had the car realigned and corner balanced as part of the service. My question is around the corner balance. This shop stated it was more important to have the front tires evenly weighted than cross weights even. This is different than I've heard previously. Should I be concerned?

Mixed use but most important for track use, most fun with driver only but regularly have passengers/students.

Measured Corner Weights w/ driver
LF 423
RF 422
LR 715
RR 616
Measured Weight Distribution
Total Weight 2176
Front-to-Rear
Front 845 38.83 %
Rear 1331 61.17 %
Side-to-Side
Left 1138 52.30 %
Right 1038 47.70 %
Diagonal Weight
Left Front / Right Rear 1039
Right Front / Left Rear 1137

[apk919]

Originally Posted by pfanning

The rear shocks on my '06 Exige with track pack were replaced under warranty. The dealer also had the car realigned and corner balanced as part of the service. My question is around the corner balance. This shop stated it was more important to have the front tires evenly weighted than cross weights even. This is different than I've heard previously. Should I be concerned?

Mixed use but most important for track use, most fun with driver only but regularly have passengers/students.

Measured Corner Weights w/ driver
LF 423
RF 422
LR 715
RR 616
Measured Weight Distribution
Total Weight 2176
Front-to-Rear
Front 845 38.83 %
Rear 1331 61.17 %
Side-to-Side
Left 1138 52.30 %
Right 1038 47.70 %
Diagonal Weight
Left Front / Right Rear 1039
Right Front / Left Rear 1137

Hmm... I wonder why they'd say that... "corner balanced" means, well, balancing the diagonal corner weights, not L/R or F/R. Your cross % is 1137/2176 or 52.3%... it should be much closer to 50.0%

Of course, it matters a bit whether the car is ballasted for one or two occupants... (was it ballasted properly?)

EDIT: Did they measure ride height, by the way? I usually measure/set ride height first, then corner balance...

[pfanning]

Originally Posted by apk919

Hmm... I wonder why they'd say that... "corner balanced" means, well, balancing the diagonal corner weights, not L/R or F/R. Your cross % is 1137/2176 or 52.3%... it should be much closer to 50.0%

Of course, it matters a bit whether the car is ballasted for one or two occupants... (was it ballasted properly?)

EDIT: Did they measure ride height, by the way? I usually measure/set ride height first, then corner balance...

The car was ballasted for the driver. Ride height is LF 125, RF 126, LR 128, RR 128.

The diagonal is the issue I'm concerned about.

[fishguy]

you want your cross weights to be %50 or really close+-1% to that, with you sitting in the car, and gas level at about the average of when you are tracking it.
also set your tire psi where you set them at the track. if you know the hot temps on track thats best also.
make them redo it correctly.

[apk919]

Originally Posted by fishguy

you want your cross weights to be %50 or really close+-1% to that, with you sitting in the car, and gas level at about the average of when you are tracking it.
also set your tire psi where you set them at the track. if you know the hot temps on track thats best also.
make them redo it correctly.

+1

My '07 S is a bit heavier than your '06, but here are my corner weights:

LF: 467# RF: 442#
LR: 715# RR: 682#

Cross: 1157/2306 = 50.17%

[EricH]

My cross weights are off about that much, it is a problem. It oversteers in tight right handers and understeers in tight left handers.

[fishguy]

Originally Posted by pfanning

This shop stated it was more important to have the front tires evenly weighted than cross weights even. This is different than I've heard previously. Should I be concerned?

you should be concerned only if you care that the people who are working on your car have their heads up their A$$e$.

I wonder what other great things they have done to your car to "improve it".

[pfanning]

Originally Posted by fishguy

you should be concerned only if you care that the people who are working on your car have their heads up their A$$e$.

I wonder what other great things they have done to your car to "improve it".

Yeah, this shop hasn't done any work for me. It was part of the warranty replacement of the rear shocks.

I talked to the owner, he's certain this will work well so I'll give it a try. I asked specifically about the cross weight effect on left vs. right turns. He claimed that's more a function of the alignment than corner balance. Not sure I believe him.

At least worth the experiment. Worst case I take to my preferred shop and pay for an alignment/corner balance.