We could say that the GMS performance rear control arms are the ultimate handling improvement for your 4C, available on the market. Or are the GMS front control arms? Well, both together, surely make for one hell of a ride.We have designed GMS performance front control arms from ground up, with one goal in mind - ultimate performance. A set (4x) of 25CrMo4, TIG welded, non parallel, unequal length, double wishbones, GMS roll correction kit and legendary GMS uniballs for razor sharp handling, unfiltered response and optimal geometry on lowered cars.
Isn\'t stock good enough?
4C has spot on most of the geometry specs for standard (non sport) suspension height (120mm ground clearance). Positive caster is a bit low making the car prone to tramlining and the rubber bushings make the front end a bit numb, but other than that it\'s very good. Bump steer is good, control arm angles are good, kingpin inclination angle is good, scrub radius is good, roll center is good. OEM setup provides a very good setup for standard suspension height (non sport, non lowered cars) and standard low grip tires. It provides neutral geometry during suspension stroke up and down which provides stable and neutral setup with minimal tire wear. Not much to improve here in terms of casual driving. Outstanding work from engineers, so leave it be or...get me going lower and faster? If yes, is your answer, then we have more for you further down...
If you are in to performance driving, we have a good news. It\'s all about the grip and optimal geometry is the key. There is always a room for improvement and GMS performance front control arms are here to fill that gap. We have improved 6 very important handling characteristics.
First - Roll center. Lowering the car without correcting the roll center, severely effects the body roll and most of 4C\'s are lower than stock height, run stiffer springs, thick swaybars and yet they are plagued by significant amount of body roll, taking away the precious grip. The solution is here. Revised geometry of GMS performance front control arms utilize special GMS ball joints which provides corrected roll center on lowered cars and decreases body roll during cornering.
Second - Dynamic negative camber gain. On stock control arms, if during cornering your 4C\'s body rolls for +3° and your run -2° of static negative camber, without any dynamic camber change, you are effectively, running +1° of positive camber that moment, which means that the car now runs only on the outer edge of tire, reducing the grip. As a solution, GMS performance front control arms are designed with inbuilt dynamic negative camber gain which means, that when the car\'s body rolls, also negative camber is gained, so if your body rolls for +3°, while you run -2° of negative camber and we add additional -1° of dynamic negative camber, you are at effectively at 0°, now running on entire tire patch, extracting the optimal grip out of your tires.
Third - Steering response. Front end in stock format feels quite numb. By replacing the rubber bushings with GMS uniballs we have eliminated any flex at the front end, making the car provide you all the required, unfiltered response to tell you exactly how close to the limit are you. On the other hand, your steering input will be much more precise, so the car will go directly where you point it to.
Fourth - Steering precision. Front end on 4C feels light, is prone to tramlining and hard to drive precisely. By replacing the rubber bushings with GMS uniballs we have eliminated any flex at the front end, making the car much more precise to your inputs. Point it the way you want to go and it will go.
Fifth - Weight distribution. By running front end a bit lower than the rear end, a weight distribution is shifted slightly more to the front, which is a very welcoming benefit on a rear heavy 4C.
Sixth - Positive rake angle. By running front end a bit lower than the rear end, creates a positive rake angle, making entire underbody of the car acting like a huge diffuser, providing the much needed downforce at high speed cornering.
Still not convinced? Check out the POV onboard of the full road blast run to secure the 1.st place in hill climb event with our GMS tuned 4C. Enjoy!
