Norm Peterson

Room for discussion on this point. Actually, the '08 GT coupe comes with that sort of brace. What it does is reduce to some extent the deflection that happens in the control arm chassis side brackets. Once you get the cornering load into the control arms, it flexes the stuff behind the control arms, starting with the CA brackets.

The S197 probably has somewhat stiffer brackets than some cars, but they still deflect. I have it on the word of an honest-to-God OE suspension engineer that suspension brackets are not nearly as rigid as you might think. As I recall, he tossed out a stiffness number in the 20,000 lb/in range, maybe a little lower. That's not all that stiff where suspension accuracy is involved (for reference, those OE rubber bushings that folks are willing to swap out without a second thought can be 10,000 lb/in or higher). Bottom line is that it's a compliance effect that can and does affect handling.

Any given individual may or may not notice it though.


Norm

clintster77

This is a more accurate statement than the previous one on post #18

When you lower your mustang the pinion angle is changed because it puts the Lcas and the Uca at a different point in their travel. Since the upper and lower are different lengths it puts the pinion out of alignment.
When you lower your mustang the inclination on the UCA and the Lcas are changed . When the inclination on the UCA or the Lcas are changed it effects the anti-squat of the vehicle. From the looks of it the lower the mustang is lowered the less anti-squat will be present .There are several ways to correct the anti-squat and pinion angle. Not all cars need the same amount of anti-squat. The amount of anti-squat needed for a drag car is different than that of a Road racer . In general a drag car needs anti squat . But a road race mustang needs a different amount of anti-squat because the Lcas are responsible for the roll steer on the back axle . Anti-squat can give the rear outside tire on corner exit the bite to accelerate out of a corner.

UCA
1. The UCA is partly responsible for the pinion angle .
2. An adjustable UCA can be useful on a lowered mustang because you can set your pinion angle back to specs .
3. I have yet to find a bracket that lets you change the UCA inclination on the 05-09 mustang. But if there is an adjustable bracket you could change your inclination and that has an effect on anti-squat ( See Lcas below for how to change anti-squat.)

Lcas
1.Lcas are to contribute to anti-squat, roll steer and pinion angle .
2.Adjustable Lcas can correct the pinion angle on a lowered mustang.
3. Lca Relocation brackets can put a extremely lowered mustang back into correct geometry by correcting the Lca inclination back to spec inclination.
4.Changing the Lca inclination with adjustable brackets can make changes in the amount of anti-squat a mustang has.

clintster77

+1 on Norms assessment

On some cars it is not only the brackets that deflect but also the frame the brackets are attached to. To a certain extent deflections and frame flex cannot be 100% overcome . But it can be factored in . Take for example a pre packaged aftermarket suspension kit that is all the rave because it is so balanced in the results it handling it gives . Now if you start adding all kinds of braces and gussets to the front suspension and you have the kit of all kits. Suddenly when you add the stiffening to the front chassis ( POW! understeer shows its ugly face ). What happened is that the chassis that the kit was designed for has been altered .To a point, chassis flex is part of the suspension . One of the problems that flex can produce is the chassis life can be shortened due to cracks produced by flex.
A G-track brace will have some effect on the cars stiffness even if it is small one way or another. Remember that anytime you stiffen up one spot on the car it has the potential to make more of a flex at some other point on the chassis . If not the chassis ,the suspension will have to absorb the forces.

an example of chassis flex from a mounting point shortening the life of one of my vehicles is . I had 2 1984 camaros both of them developed a crack right behind the steering box. One of them almost tore off the frame because after a very hard on cars teenager (me) drove it so hard. the repetition of flexing back and forth and back again took its tole on the unibody frame.
A simple $25 dollar bolt in gusset that was standard on the Z28s would of prevented this . The moral of this story is just because something cant be felt during driving when you bolt it on doesn't mean it's not doing something .