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The Warwick Racing Electric Vehicle Grand Prix (WREVGP) is a team of 8 final year engineering students from the University of Warwick, U.K., who have developed an electric go-kart to compete in the EVGP 2013. We aim to build upon our success from the EVGP 2012, and are back this year to defend

our title through powertrain optimisation, mass reduction and increased protection.

WWWARWICKARWICKARWICK RRRACINGACINGACING EEELECTRICLECTRICLECTRIC VVVEHICLEEHICLEEHICLE GGGRANDRANDRAND PPPRIXRIXRIX Chassis DivisionChassis DivisionChassis Division Lightweight materials

Results Use of CADCAM and tests to ensure high quality components and reducing material waste and manufacturing time Optimised handling through movement of cells to allow best weight distribution ratios. Use of Magnesium to significantly reduce weight of kart, thus increasing fuel efficiency and acceleration. Use of Tritek to create lightweight, impact resistant structures, reducing potential pit stops and improving green credentials of kart.

Computer Aided Design

Sustainable Composites

Lightweight materials

Weight Distribution

Every component on the kart was modelled to have a complete digital model of the kart, this included reverse engineering of standard karting parts.

CAD was used to ensure designed parts were safe and compatible with other components

Finite Element Analysis (FEA) were carried out to ensure designed parts were able to sustain loads that occur in typical racing conditions.

CAD allowed right-first-time manufacture. This led to reduced manufacturing time and material waste.

CAD models allowed usage of Computer Aided Manufacture (CAM) for highly detailed

The team explored lightweight materials as alternatives to common materials used in industry, including magnesium and titanium. Magnesium is a high strength material that has a density 35% lower than aluminium. This makes it ideal for reducing the mass of the kart. Lap shear test results ensured the strength in magnesium welds. Showing great potential as an alternative material for the battery cases. Titanium was investigated as material to use for the floor tray, track rods and stub axle due to its high strength to mass ratio. Using extensive CAD and FEA, a complex stub axle was designed and manufactured using an advanced manufacturing process: Selective Laser Sintering.

Weight distribution of the kart greatly affects the handling of the kart. The team aimed for an equal (50:50) weight distribution ratio between the left and right side of the kart and a 60:40 ratio between the rear and front wheels. This was successfully achieved through the placement of cells; the left case contained more cells and was

located towards the rear to compensate for the weight of the motor.

Sustainable materials greatly improve the green credentials of our electric vehicle. A 100% polypropylene composite, Tritek, was investigated and used as a material for our crushable structures. This material provides many benefits, including:

Lightweight, impact resistant and non-conductive protection structures.

Fabrication optimisation of a revolutionary full-recyclable material to

Weight Distribution Ratios (%)

Left : Right Back : Front

50.6 : 49.4 59.4 : 40.6

WWWARWICKARWICKARWICK RRRACINGACINGACING EEELECTRICLECTRICLECTRIC VVVEHICLEEHICLEEHICLE GGGRANDRANDRAND PPPRIXRIXRIX Powertrain DivisionPowertrain DivisionPowertrain Division

Battery Optimisation

Reliability

Dynamometer Testing

Throttle System

Results Putting the system improvements into action has resulted in one second per lap improvement on the 2012 kart. Reliability improvements allow the kart to run safely and continuously without failure for long periods. Understanding of system knowledge allows the kart to be quickly adapted to suit the race conditions.

Battery Selection: Testing of all 93 of our individual GBS-LFMP60ah cells has

allowed us to select the best 44 cells required to power the kart (2 full batteries). Characterisation of cell voltage under discharge and cell resistance allows the best cells to be selected. This process has allowed an improvement of 1.5% in available energy between the randomly picked 2012 kart cells and the matched 2013 cells which will transfer to valuable power to drive the motor on track.

Actual Motor Performance Analysis: Test rig allowed drivetrain testing using dynamometer. Experiments conducted under strict conditions such as an independent fixed voltage supply have allowed efficiency, reliability and power to be improved. Additionally system knowledge has been gained which allows the system to be adapted to suit the required performance.

Bosch WP120: replaces our

standard throttle. This provides superb linearity, light-weight and motorsport industry quality.

Reliability Improvement: Use of

high quality connectors allows the system to be quickly un-assembled and re-assembled without damage. Improved covering of electronic components makes the system less exposed to damage by debris and precipitation which improves the safety of running the kart. This has allowed us to run the kart in rain and even snow without issue.

On-track Testing: Tests completed in

the laboratory and workshop put into practise on the track. Use of data logging equipment has allowed selection of optimal kart setup and gearing, race strategy testing and driver training. Parts manufactured to adapt the standard kart chassis for electric drive given full race length tests to prove race worthiness.

ESC: Sevcon Gen4 72V 350A

Motor: Motenergy PMAC-DS

Batteries: 22 GBS-LFMP60ah cells

BMS: Elite Power Solutions

Throttle: Bosch WP120

Performance:

Over 10kw of continuous power

Almost 90% efficiency

Durability allows extended running

periods

System Specification

On-track Testing

WWWARWICKARWICKARWICK RRRACINGACINGACING EEELECTRICLECTRICLECTRIC VVVEHICLEEHICLEEHICLE GGGRANDRANDRAND PPPRIXRIXRIX OutreachOutreachOutreach

Imagineering

Local School Careers Event

IMechE-Nissan FS Event

MIA International Low Carbon Racing Conference

The WREVGP team has participated in numerous outreach events throughout the academic year. These activities aim to engage and educate the local community and students on engineering and technology areas. The team was able to share their experience and knowledge to promote the future for green, efficient and sustainable technology; reaching an approximate total footfall of 20,050. Major events, including future events are described below.

Cheltenham Sustainable MotoExpo

Footfall: 10,000 The Imagineering fair held in Coventry, aims to promote Science, Technology, Engineering and Maths to local school children aging from 6-16 years of age. The team gained high levels of interest from children and parents from showcasing our battery powered go-kart. The team also had the opportunity to meet the mayor. Children were able to take a seat in the kart and learn about battery powered vehicle

Footfall: 300 Our kart was exhibited at Bedford Modern School, where the team met children, parents as well as fellow engineering university students.

The projects aims for encouraging a green future for motorsports were well received and followed with eager questions on the development and engineering of the kart. The team was also able to meet some leaders in the Formula 1 industry.

Footfall: 300 Our team participated in the prestigious annual conference. At the event were some of the biggest names in low carbon racing such as Drayson Racing, TTXGP, Ricardo and of course WMG. The event is designed to promote trade for low carbon racing business including promotion of low

carbon racing and its future part in creating low carbon transport systems. A large focus of the event was to push the excitement that can be found in low carbon racing and the Warwick EVGP kart got plenty of attention from enthusiasts, as our kart is a great example of the excitement that can be had with low carbon racing.

Footfall: 150 WREVGP and the kart supported a WMG careers event at Cardinal Wiseman School, a local school. A presentation was given to children aged 12-14 to encourage science and engineering through the promotion of our project.

The team have worked with Cheltenham Motorsports, Coventry University and Sutherland Campbell Marketing to plan the UK’s first EVGP race. The competition will be held at the Cheltenham Sustainable MotoExpo in September and the team have assisted in planning the required facilities, competition regulations and track layout.