Envirage has been involved in WTAC since 2010, firstly with the Lotus Exige GT3 driven by Warren Luff then with the Autotech Engineering Subaru STi - Hulk and with the Sutton Bros Silvia. In 2014 RP approached Envirage with the aim to produce a Porsche 968 for Open class. After attending WTAC in 2014 as a spectator RP fell in love with the Pro class car concept and the result of one year of passion for engineering is the RP968.

Front Upper and Lower Control Arm Design

The images illustrate the control arms designed by Envirage. Both controls arms are quite unique, and this is due both mechanical and aerodynamic considerations. The lower control arms are designed out of aero tubing due to its placement in direct airflow. This meant the upper control arms were required to carry the tire loads to the struts. CNC machined sections were integrated to the round tubing to provide the strength required.

Suspension Design/Uprights

The suspension geometry of the RP968 was designed by Envirage through specific engineering calculations and simulations. The final suspension pick up points from these simulations were employed to design the RP968 Uprights. The upright connects the tire/wheel and brake package to the chassis and is a vital component of the car. The uprights were designed by a new Sydney based company called Brypar. It went through several iterations as the mechanical and aerodynamic loads increased and hence required structural analysis at each evolution.

Aerodynamic Bodywork Structural Design

Front Splitter/Canards

The aerodynamics package and bodywork designed by Sammy Diasinos (Dynamic Aero Solutions) required specific structural design and analysis. The aerodynamics components were manufactured employing light weight carbon fibre composites. The software package Strand7 enabled the engineers at Envirage to model the composite laminate schedules and run finite element analysis to evaluate the strength and stiffness of the components.

The front splitter was a significant component that required analysis and optimisation due the loads it would experience. The front wing that extends from the splitter section is loaded in a cantilevered manner and had large aerodynamic loads acting on it. Therefore it was vital that the front wing had the necessary strength and stiffness to support the loads. The second image illustrates the different lay-up sequences employed in the front splitter. There is also an internal structure that was inspired by aeronautical wing sections, and hence incorporate structural spars and ribs.

Undertray/Floor

Similar to the Front Splitter the Undertray/Floor section required several iterations of structural design. It was vital to provided significant stiffness at the centre of this component as the maximum loads are experienced at the entrance of the diffuser section. The mounting solutions (T-Bracket) also required analysis and verification as this would transfer the aerodynamic loads to the chassis.

Rollcage Design and Analysis