KYWes

Are there any downsides to installing LCAs on my 95 Z28 Vert? Cornering vs straight traction etc. If you relocate the rear lower control arms do you need an adjustable panhard rod? I've read an adjustable panhard rod in necessary if you lower the car but what about just relocating the LCA? Also have you seen a definite improvement in traction and launch with LCA relocators?

Injuneer

The LCA's can have a negative affect on cornering. If you opt for rigid polyurethane bushings, the LCA's can "bind" when the body starts to roll in a corner and the front bolt that holds the LCA to the body is no longer parallel with the rear bolt that holds the LCA to the axle assembly. For cornering applications, you need to make sure the LCA "ends" incorporate a means to allow the front and rear bolts to rotate out of parallel. That can be accomplished with 1) a poly bushing on the axle end and a softer rubber bushing on the body end, 2) a spherical rod end on the axle end and a poly bushing on the body end (minimal noise transmission to the body) or spherical rod ends on both ends of the LCA (will transmit noise to the body, and spherical rod ends vary in quality, and can wear out quickly).

For straight line racing, the poly on both ends does not present any problems.

If you don't mind the harshness and a bit of noise, I'd recommend the spherical rod ends, using high quality components. I have the Spohn Performance LCA's with rod ends.

No need for an adjustable panhard rod when you add LCA relocation brackets. The location of the lower holes are radiused so nothing changes except the angle the LCA makes with the ground.

You might want to ask the guys who drive their cars around corners (auto-x, road racing) if the LCA relo brackets affect handling and braking in their applications.

KYWes

Thanks for the info Injuneer.

Norm Peterson

Don't know if you've done anything with this in the meantime, but you may still be able to use this . . .

You wouldn't need an adjustable PHB just because you added relo brackets for the LCAs, but you might install one as a separate consequence of lowering the car. Lowering the car will cause the axle to shift laterally a little, and an adjustable PHB allows you to correct for that. As well as for any errors in getting the axle properly centered during production. Either way, this lateral axle location thing tends to become more visible when you swap out the original rear wheels and tires for wider ones.

LCA relo brackets do have some effect on handling, as any time you alter the side view inclination of the LCAs you also affect how much (and which way) the rear axle steers as the car rolls in a turn. Once you lower the rear of the car, you've generally changed the amount of axle steer to make the car understeer a little more. Some notice this, many probably do not, and at least it's in the "safe, stable" direction. You can get the original amount of axle steer back if that's what you want by carefully relocating the axle side LCA pickup holes.

Let me emphasize "carefully" here, because when you drop the axle sides of the LCAs too far the axle steer goes oversteerish (probably not heavily so, but perhaps enough to feel a bit uneasy in hard cornering or accident avoidance maneuvers). Offhand, as a corner-carver kind of guy with at best limited interest in drag racing I wouldn't want the relo bracket holes to be much further down from the OE holes than the amount I lowered the car. IOW, lower 1", drop the LCAs 1" at the axle. Most relo brackets probably don't have a high enough hole setting for mild drops, like that 1" or less, but fortunately there is a little slack here and it's not exactly a pass-fail boundary that you cross if the axle steer goes a tiny bit "loose". Worst case, you can crutch it with stiffer front springs or a thicker/stiffer front sta-bar.


Norm