I have a 2011 GTCS, lots of power upgrades, recently went with a Steeda lowering set up, springs, struts, shocks, LCA, etc..
Two months ago I had the front LCA replaced with the Boss 302 version, Steeda bump steer kit installed. Before you change to a stiffer set up, there is a TSB for the electronic shudder, mentioned above. Get it flashed, not sure if it is a guaranteed fix. I was unaware of the issue, guy at Steeda forgot to mention the possibility of this scenario. Wife picked up car, shudder kicked in first at 80mph! Luckily didn’t wreck her!! Bottom line, Get it checked. I ended up upgrading to the Boss 302R steering rack. Expensive but fixed the problem. I was leery about taking car to a dealership since it S/C with a custom tune. Btw, I love the Steeda suspension.
2011 GTCS, 3.42 6sp ARH LT headers, race cats, x-pipe, FR SVT mufflers, Roush Stage 1 Supercharger, Axle Exchange 4" Aluminum DS, SPEC stage 2 clutch, JLT Cold Air intake, FR Short Shifter, Tune by Breenspeed, Kenny Bell BAP, Blowfish shifter bracket, JLT PCV, FR forged wheels 19"x9, 19"x10, FR GT-500 Bremo brake kit: 15"front/ 13.8"rear, Steed LCA, Steeda tower brace