Triple Eight Race Engineering, based near Silverstone, was formed in 1996, primarily to design, build and race the Super
Touring Vectra on behalf of Vauxhall Motors.  A close working alliance developed and Triple Eight has now become Vauxhall's technical partner in UK Motorsport.

 

Whilst Triple Eight have their own in-house design department with state of the art drawing office facilities, they currently outsource all their carbon fibre work.  This involves the machining of complex tooling prior to the production of their carbon components, which can result in long lead times.  The Motorsport industry demands fast turnaround and new designs of components need to be built and tested in extremely short timescales.  Triple Eight’s designers therefore decided to explore Rapid Prototyping as an alternative method.  Wanting to identify the potential benefits of using Selective Laser Sintering (SLS) technology in the development of their prototype race car engines, they embarked on a testing programme in conjunction with 3T RPD Ltd.

To enable Triple Eight’s Engineers to understand SLS technology further, it was concluded that confidence would need to be gained by analysing a traditionally manufactured Carbon Fibre component, and comparing performance data against a fully Laser Sintered prototype model of the same part.  The component identified for this purpose was an Inlet Manifold:-

 

 

To evaluate tolerance issues that may arise from the process and identify areas that could benefit from post-processing such as machining, metal inserts and surface finish improvements, it was agreed that a ‘snap shot’ sample part of the Inlet Manifold would be produced in Glass Filled Nylon using the SLS technology.  3T produced the Flange (as illustrated below) so that the Engineers could measure the sealing areas.  The outcome was positive, as they concluded that seal features could be left in the model but that location holes would be machined in afterwards.  This gave the best possibility of the full prototype succeeding and gave the Engineers initial exposure to the technology. 

 

Having proved the viability of SLS, Triple Eight’s Designers supplied 3T with 3D data for a fully detailed prototype of the Inlet Manifold to be built in Glass Filled Nylon.  With the UK’s largest SLS facility and some of the world’s largest Laser Sintering machines, 3T are able to produce prototype parts with extremely lean leadtimes.  The Manifold was shipped to Tripe Eight just four working days from receipt of data.

3T’s team of Engineers are experts in their field and their knowledge of both their CAD systems and Laser Sintering machines ensures that they consistently produce accurate, functional parts with the best surface finish and mechanical properties possible.  Prior to building the component, 3T’s CAD Engineers determined the best orientation for the part to built in to ensure that the surface finish generated would be of the highest quality within the flow outlets.

 

Triple Eight’s Engineers analysed the Manifold on a fully built race engine on a dyno, therefore subjecting it to extreme vibrations and required chemical resistance to fuel.  They reported that the Manifold initially saw a pressure drop (power loss) at the very peak rpm as air speed was approaching maximum.  They assumed this was due to internal tract surface finish.  As the majority of the power curve remained the same when compared to its carbon equivalent and highest rpm figures are not high usage in a circuit condition, they considered the Manifold acceptable for dyno testing.  The Manifold was fine under vibration and heat cycles, even withstanding a back fire.  The Test Engineer said the tract glowed momentarily as it shone through the Glass Filled Nylon tract wall of the SLS component.

 

 

Triple Eight’s inspection of the manifold on a CMM (Co-ordinate Measurement Machine)

 

Manifold built up with injectors, fuel rail and loom

 

The SLS process produces extremely functional parts, some of which have been found to be durable enough to be used as direct production components on race car engines.  The major advantage of the process is that a part can be built in a choice of materials directly from the designer’s 3D CAD data, without the investment in time and money of conventional tooling, thereby making it a fast, flexible and cost-effective manufacturing method.

Graham Lawrence, Design Engineer at Triple Eight Racing says “This project with 3T has given us the confidence in geometrical conformity and material strength when using rapid prototyped parts on the engine dyno.  The advantages of this become very clear when you can have a number of parts from conception, through the SLS process, inspected, built up and on the dyno within 2 weeks.  The nature of SLS components gives freedom of design for development work, as complex tooling can be discarded until final race systems have to be produced, reducing design time and manufacturing costs.  The next stage will be the use of rapid prototyped parts in dynamic application on the circuit.”

 

Further information on Triple Eight Race Engineering can be obtained from www.tripleeight.co.uk.