The ARC R8.4LCG – 1/8th On-Road Racing Car Kit is based on the R8.4 but with a low center gravity chassis design. The front and rear upper arm bases are all new parts, with the lower arms and steering blocks molded in hard composites to increase overall traction and corner speed.
LOW CENTER GRAVITY DESIGN – The new R8.4LCG chassis R842026 is now standard and, together with the R822025 LCG engine mounts, the engine is lowered by 2mm compared to the R8.4. The LCG chassis not only lowers the engine mount but also increases flexibility in the rear end of the chassis and increasing the steering response of the car.
HARD COMPOUND PARTS – The front steering blocks and lower arms are now molded from harder composites. The hard arms are also lighter than the standard arms and this combination increases traction and handling consistency under all conditions. The use of hard composites significantly improves the corner speed of the R8.4LCG.
ADJUSTABLE UPRIGHTS – The front and rear uprights on the R8.4E are designed with eccentric inserts. This allows the axle height and direction to be changed for fine tuning the wheelbase and roll center. Both uprights can use big (12x21mm) and small (12x18mm) ball bearings with insert.
NEW FRONT AND REAR UPPER ARM POSITION – The R8.4LCG features front upper arm holders that are 1.2mm higher compared to the R8.4. This changes the roll center in the front end and delivers quicker handling response with reduced exit steering. This reduces the tendency for the car to oversteer when exiting corners under hardacceleration. The rear upper arm plate is also new and features a horizontal plate with three adjustment positions. The inner most positions gives more rear traction and higher stability while the outer most position delivers a quicker response thatflows with the front end.
ALL NEW BIG BORE SHOCKS – The shock height has been lowered and positioned further outboard, delivering significantly improved steering response and corner speed to the R8.4LCG. NEW BIG BORE R8.4LCG Shock absorber Front 64.5mm 13mm. With the R8.4LCG, ARC introduces new 13mm big bore shocks to its 1/8th platform. 13mm bore shocks have been successfully utilized in our 1/10th electric cars for a number of years. With its larger 13mm bore, they hold a larger volume of silicon oil which improves consistency and reduces maintenance.
ALL NEW BIG BORE SPRING – A new big bore spring set features 20mm front springs with 5 different hardness from C7.6 to C9.9, and 25mm rear springs with 4 different hardness from C6.5 to C7.7.All springs are finished in a black coating with colored markings for easy identification.
ALL NEW LOWER SUSPENSION ARMS – The new front and rear lower suspension arm design is a result of extensive R&D during the 2022 racing season in various traction levels around the world. The new arms are thinner all around but features reinforced areas in the rear lower arm for better impact resistance. The new arms bring significantly more corner speed and makes the car much easier to drive. These improved characteristics have been proven across various traction levels and at varying tire diameters.
NEW MIDDLE BELT TENSIONER – With the middle belt being the longest belt, this can result in the belt flipping over the rear pulley under super high traction conditions. The new middle belt tensioner features an additional ball bearing just above the rear pulley for significantly reduced belt deflection and prevents the belt from disengaging even under the harshest racing conditions.
NEW FRONT AND REAR BULKHEAD – The new front and rear bulkheadsnow featurerecessedmountings for the anti-roll bar ball bearings. This increases the contact surface area for the anti-roll bars, bringing more precision to the chassis‘ handling response.
NEW ANTI ROLL BAR STOPPER – There are 5 different anti-roll bar stoppers for R8.4-2.2mm, 2.4mm, 2.6mm, 2.8mm, and 3.0mm – with each stopper being tailored specifically for each anti-roll bar thickness. Doing this ensures precise suspension operation, reduce tweak and greatly improved handling consistency, especially during long finals.
NEW MAIN SHAFT BULKHEADS – The new main 2-speed shaft bulkheads are designed to move each side ball bearing as far outside as possible to reduce stress on the ball bearings. Combined with a carbon fiber stiffener above the bulkhead, flex in this area is significantly reduced, the stiffener can increase shaft rotation stability and increase the efficiency of the transmission.
NEW BUSHING FOR MAIN SHAFT BALL BEARING – The new bushing design for the main shaft comes with two dimplesthat slot inside the bulkhead. This prevents both the bushing and the bearing from spinning at the same time, further improving drivetrain efficiency and the overall durability of this assembly.
IMPROVED ADJUSTABILITY AND NEW ARMS – For added tune ability, theR8.4LCG features adjustable front and rear suspension arm lengths and roll center via changing the pivot pin inserts. Racers can choose from 3 different front low and upper arms length, The rear low arm roll center can settle in middle or low and rear upper arm lengths also can adjust. Racers can setup their car to the best geometry according to track conditions. The default setup places the front lower arms in the center — with a longer front low arm can generating more traction while a shorter arm delivers better steering response.
WHEEL DISK – The optional wheel disks are available for both front and rear upright, the wheel disk can reduce the turbulence inside the rim can improve the stability, especially in high-speed corners.