MAN VI

Chassis

After experiencing weight issues with the Man05 chassis, the Man06 chassis was designed to overcome this particular problem to ease manoeuvrability and reduce the overall weight contribution to the car.

The Man06 chassis consists of a steel tubular space frame with an overall weight of 30kg. The design utilised a stressed engine with all load paths optimised to transfer loads into the engine through efficient triangulation.

The steering rack has been positioned below the natural arc of the driver’s legs as this space would otherwise be unused and allows a direct line along the steering linkages. The front suspension components have been placed either side of the drivers legs to keep the centre of gravity low whilst minimising the angles through which the suspension forces are transmitted.

The suspension forces on the rear chassis have been directed almost straight into the engine. They are positioned above the drivetrain to minimise interference between the moving components. The chassis has been manufactured in-house employing a tubular jig that allowed each component to be positioned prior to welding. The fire wall and floor have been manufactured from lightweight aluminium and composite panels to minimise weight.

Engine

The intake manifold was designed with the use of CFD software Fluent and GTPower Engine Simulation software for maximum volume flow rate. This was achieved by incorporating smooth flowing faces and gradual changes in cross sectional area within the manifold.

The intake runners were tuned to use the pressure waves generated, to provide power boosts at desired RPMs. The incorporated twin plenum chambers improved the throttle response of the car, which is an important feature on the tight FS track.

The intake was made out of a nylon 12 polymer, impregnated with a silicon rubber for general protection, using Selective Laser Sintering to achieve the desire shape of the intake.

The engine was upgraded to a hydraulic clutch on a bespoke three-pedal pedal box.

Drivetrain

The main aim for the drivetrain on the Man06 was reduction of weight to that of the Man05. The drivetrain for the Man06 consisted of a spool arrangement which replaced the typical differential set-up. A spool is a type of locked differential, which, unlike a standard open or racing limited-slip diff, ensures that both driven wheels rotate at the same speed.

The Tsubaki Alpha 520 chain, a Renthal Ultralite sprocket and hollow 7075-T6 aluminium alloy driveshafts, all helped contribute to the dramatic weight loss on the car.

The heavy CV joints used on the Man05 were replaced by four flexible composite disc couplings manufactured from GKN which offer very low weight and inertia without compromising performance.

The discs are mounted between 2 aluminium flanges – one bonded to the driveshaft and the other bolted to the spool, employing an arrangement of steel dowels to transmit the driving torque. An identical flange/dowel arrangement is used to transmit the torque to the hubs, reducing the complexity of design and manufacture.

Electronics

The wiring loom for the Man06 was designed around the DTA manufactured E48 EXP ECU. The car has an electronic fuel injection system which is controlled by the ECU. For the injection system to work, a range of sensors were wired to the ECU (e.g. fuel and temperature sensors), which also included electronic fuel and ignition maps which have the ability to be changed remotely with a computer to tune the engine.

A steering wheel obtained from Farringdon Instruments has the capability of measuring the following variables: speed of the car at the wheels; engine RPM; water temperature; oil pressure; battery voltage; gear number; number of laps completed past a remote beacon; fastest Lap time. The system also incorporates accelerometers in the longitudinal and lateral planes and allows for data acquisition of all the parameters discussed.

Tyres

The Man07 will be using Keizer 10″ SAE rolled aluminium rims imported from California, with hubs and wheel centres designed and manufactured in-house. The design of the wheel centres will be optimised by carrying out intensive FEA to ensure they will be long lasting and robust for the length of the competition. The light weight Keizers will prove to be advantageous during acceleration.

The tyres used are Hoosier 18×6-10 R25A, selected using data from the FSAE Tyre Test Consortium.

Brakes

A four wheel braking system was utilised on the Man06 with the use of two different sized AP Racing brake calipers. The front brake calipers were larger, where a greater braking force is required – the four pot CP4227 model, whereas the rear calipers were smaller – the CP4226 double pot model. The in-house manufactured and designed brake discs were laser-cut from 4mm thick mild steel and were used for all four calipers.

Brake balance adjustment had been integrated on the car which allowed the driver to control the brake distribution at the rear and front by means of a switch on the dashboard.

Bodywork

The bodywork on the Man06 is made from carbon fibre, with a total weight of just 2.4kg. A master plug was made using blue foam and pieces of MDF, to which clay was applied to help create the desired shape. A mould of the master plug was then created using Glass Fibre to which carbon fibre sheets (twill weave E644 resin based) were laid.