I have a set of bmr lcas waiting to be installed and i'm considering getting some roush lowering springs for just the rear of my car. what i was wondering was, do i need relocation brackets for the lcas to keep them 'aligned' right when i lower just the rear? or will the oem placements work? thanks


**edit** i think i already answered my own question, but if anyone would still like to respond, feel free

 

If you still have any questionsa this link might help answer them http://www.cherod.com/mustang/HowTo/LCA%20_adj.htm

 

great Job

 

that's actually what i read when i 'answered' my own question earlier. thanks, though

 

OE placements will work, just not as well as with the lowered axle pivot points.

The linked description is OK as far as simplified explanations go, but a couple of things were left out.

The inclination of the upper arm also has an effect on launch traction - actually it's a combination of UCA and LCA inclinations that taken together define the side view instant center ("SVIC", or perhaps you've heard the straight line guys mention "IC" - same thing) and "anti-squat". More of this "anti-squat" means that more force planting the rear tires comes through the suspension and happens immediately. As in faster than it takes for the rear of the car to physically squat into its new position because it takes a little bit of time for the springs and shocks to compress.

There's another benefit to using relo brackets on a lowered car. Very briefly, that concerns how much (and which way) the rear axle steers as you take corners. Your rear axle does not remain at exactly 90° to the car's longitudinal centerline even though it's easy to think that it does - it "steers" as the car "rolls". In a lowered car with non-relocated LCAs, there will be more axle steer, and this tends to make the car feel clumsy when you make sudden steering inputs. At autocross, this is most noticeable in slaloms and the car will feel like it's fighting the right-left-right-left rhythm that you want it to have. On the street, a similar situation might be if you have to suddenly dodge something in the road (piece of truck tire carcass, pieces of cinder block, pothole, animal, etc.). Relo brackets can restore this sort of emergency handling behavior approximately back to OE levels for the lowered car.


It is possible to overdo anti-squat, and it is also possible to change the axle steer too far and make the car "loose" (just like it sounds, if you're pushing it hard enough). It may be fortunate coincidence that the folks looking for every last bit of help in the quarter mile aren't apt to be interested in doing lots of really hard cornering with the same car.


Norm