When it comes to safety, say "No!" to shortcuts and inferior solutions.
 
GMS Carbon harness bar is the lightest (1090g), strongest (3x stronger than Ti6Al4V Grade5 Ti) and safest (FEA simulated decceleration force of up to 50g) harness bar available for the 4C on the market. It features a specific, oversized 40mm, thick wall, prepreg, carbon fiber tube with unsurpassed strength. This specific carbon fiber tube boasts 11x higher (1100%) ultimate tensile strength (3500 MPa) compared to T6-6061 Aluminum alloy (310 MPa), 5x higher (500%) ultimate tensile strength (3500 MPa) compared to 4140 CrMo (650 MPa) and 3x higher (300%) ultimate tensile strength (3500 MPa) compared to Ti6Al4V Grade5 Ti (1200 MPa). However, even being one of the strongest constructional materials in the world, this material is also undisputed champion of its own league, when it comes to the weight. This particular carbon tube has a specific density of only 1.5g/cm3, the T6-6061 Al 2.8g/cm3 (186% heavier), Ti6Al4V Grade5 Ti 4.42g/cm3 (295% heavier) and 4140 CrMo 7.85g/cm3 (5x heavier). Of course, to achieve the same strength as this carbon fiber tube has, the mentioned materials (Alu, Ti, CrMo) would have to be significantly thicker to provide comparable strength, which means to achieve a Aluminum tube that would be as strong as this carbon fiber tube is, it would have to be significantly thicker and therefore also heavier. If we conclude the given facts, the GMS carbon harness bar, utilizing this specific carbon fiber tube, has far superior strength / weight ratio, compared to any other harness bar on the market.
 
The mounting brackets of the carbon tube are CNC machined from high strength T6-7075 aluminum monoblock to ensure safe and strong attachment to the chassis / monocoque. Due to the safety reasons (tearing of attachment points in case of crash), the entire assembly is rigidly mounted behind the rear firewall (requires cut in the firewall) and secured to the chassis with 4x M10 bolts to the OEM roll bar attachment points. This are the only attachment points on the car which are strong enough not to fail under deceleration forces of your body being stopped by the safety belt in case of serious crash.
 
Why? In case you have 70kg and you're crashing with speed of 50km/h, head-on into the solid object, this translates into 41G of deceleration for a few milliseconds, which means over 3000kg of force rendered on your body. Of course, cars have crumple zones designed to absorb the impact force and with 4-point or 6-point harness, this force is then even further reduced and distributed accordingly to the belt attachment point on the chassis, still a force in excess of 500kg is easily exceeded on the harness bar in such case. Most of aftermarket harness bar solutions rely on strong harness bar, but are unfortunately mounted to undersized attachment points or utilize inadequate adapters. Remember, the chain is only as strong as its weakest link is, and having the harness bar mounted M6 or M8 bolts is the weak point of the assembly, regardless of the harness bar strength. 
 
We strongly suggest not to interfere with car's safety equipment, unless the upgrades are engineered with a decent safety margin. Your life depends on it.
 
GMS lightweight rear firewall cover (sound insulation) available as an option.
 
Requires drilling in the rear firewall!