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Jacer has developed its design over 10 years, resulting in the recently debuted F2k6 model.
There were a number of design factors that Jacer wanted to address
carrying over from the evolution of the V2k series cars.
One of those factors was thermal dissipation, the previous Jacer models has high engine oil temperature issues, and Jacer has worked hard in designing the F2k6 to allow heat to be expelled from the rear of the engine cowling, along with better cool airflow under each side of the engine. The factory car that raced at the 2005 FV Nationals peaked at 118 degrees C, somewhat lower than cars competing against it.
Another factor was combining a modern Formula One styling with increases in aerodynamic efficiency. The design took on a raised nose profile, allowing air to travel under the H Beam, and be “split” out each underside of the car. The frontal area of the F2k6 has been reduced by 25% from the V2k series. The cockpit is 55mm lower than the V2k , and the frontal section maintains its narrow profile for 80mm further from the nosecone.
The chassis has been made stiffer and stronger, to aid in both helping keep its occupant safe, and also to allow the suspension to do more of its job, providing more tuning opportunities.
The front suspension has also been modernised, now featuring a twin inboard bell crank system, utilising Polar adjustable Gas shocks. The Jacer rockers sit out from the front of the chassis to increase the ratio of the pushrods to the bellcranks, better utilising the geometry of the VW front torsion arms.
The rear suspension has been refined to take away the complicated rocker mounting system that the previous Jacer models utilise. Whilst still under development, the new rockers have worked well, and combine with a lighter and shorter rear shock, helping to reduce the mass high above the rear of the car, helping with rear roll centre characteristics.
The changes to the rear suspension have allowed the exhausts and gear linkage to be neatly packaged in front of the axles and under the diff, providing better airflow, and a tidier rear end. Along with the narrower rear chassis, the exhaust can now also be shortened to allow options for engineers to play with shorter or longer exhaust primaries.
Styling changes also have incorporated some functional advantages. The main body section that the V2k series uses has been split into two separate sides and a bonnet, allowing the sides to stay on the vehicle more often, and the bonnet is able to be removed for access to the front suspension, brake and clutch reservoirs, steering, electrics and pedals. Another styling change is the addition of the fibreglass rainlight / rear body mounting panel.
The car is very much within reasonable weight limits. The new design had a driver of 70kg, and required 14kgs of ballast to be added to reach 491kg. In other words, an 84kg driver will be right on min weight.
The final major consideration that has gone into this design is the rigidity of the engine bay area. The engine bay is now braced in four directions and has two tiers of chassis rails to strengthen the entire rear area. The F2k3 design added 100mm of length to the V2k design, however this proved to cause some twisting in those cars, which has now been rectified on those models. The F2k6 has taken the full length a step further and ensured that the engine bay is much stronger, resisting twisting and being able to withstand more impacts.
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