Need some help?AcceptDecline
 

Manifold Development

 

JBS Developments have been busy working on a new range of Cast Iron and Tubular Stainless Steel manifolds for the full VAG range.

The manifold has been designed using the latest high powered CAD packages to optimise the collector, runner flow capabilities and to enable easier fitment. The CAD process allows us to manipulate the part quickly, while also allowing information and measurements to be taken easily, which would be physically impossible to do by hand.

Once happy with the design, it was sent  for rapid prototyping thus giving a physical model to evaluate, before any design finalisation could take place. The rapid prototype is a highly accurate model taken straight from the CAD model data.

The prototypes are produced from SLS 3D manufacturing process. This uses an Argon laser to draw the design, one slice at a time, onto finely powdered nylon, whilst melting the layers together (sintering) to form a solid component.

Because the process is fully self supporting, it allows for parts to be built within other parts with complex geometry that simply could not be made any other way.

We also use SLA rapid prototyping - this process is similar to SLS but uses a solid state laser to draw onto a UV Photopolymer. This technique allows an impressive level of accuracy and detailing to within +/-0.1 per 100mm.

Once constructed, the model is hand finished to retain design precision and product quality.  A range of surface finishes are available to highlight and distinguish features of the model and make it look like the real thing.

The rapid prototype (RP) gives a huge advantage in being able to fit the manifold to an engine with a turbo, to test and ensure that the product achieves its specification.

Having a physical model of our manifold design means we are also able to flow test and compare the results to our CFD (computational fluid dynamics) data before being sent for casting.

Computational fluid dynamics (CFD) is an analysis tool we use with our CAD design packages. It allows us to simulate flow through the CAD model during the design process. CFD reduces the need of rapid prototypes, as it helps with the early stages of development, but it doesn't replace the physical data taken from the RP's.

Being able to flow test our rapid prototypes has helped in developing the manifold to flow considerable better than previous models and others on the market. This is due to the complex design and hours spent on CFD for individual runners, giving the exhaust gas better flow and balance throughout the runners.

Once happy with the designs and they have been tested, they are then sent for manufacturing.

During the manufacturing process we receive a production prototype/sample. This is usually the first of the batch, it allows us to check the quality of production and to run real life tests.

All the manifolds are thoroughly tested and dyno'd. At which time all power and flow figures are released.

At JBS we will only release a new manifold once all testing is complete and we are happy with the results.

Design Theory

All our exhaust manifolds, downpipes, inlet manifolds and boost pipe work are designed to give optimum flow, using the best materials and manufacturing processes.

Controlling and optimising the flow of air and exhaust gasses through the pipe work is the key part of JBS' development process.

For the manifold design, changing the direction of the flow in such a way gives better directional flow of the gas into the turbine, as well as defeating port sharing, all of which are key features.

Port sharing occurs on many of the flat manifold designs produced by other companies and leads to turbulence in the runners. Turbulence causes uneven gas flow through the pipes resulting in lower performance.

During the design process manufacturing, reliability and assembly are a necessity in producing a high performance easy to use product.

For example, the cylinder head flange has been designed to allow greater thermal expansion and movement between the runners. This prevents cracking and warping due to the exhaust gas temperatures produced. We found that a too restrictive flange forced stresses back through the runners of the manifold  leading to crack propagation.

All JBS products have been designed to fit best optimising OEM products, such as boost pipes and turbo in pipe work. Also the physical shape has been designed to help with fitting - (manifold runner paths).

All our exhaust manifolds, downpipes, inlet manifolds and turbo kit components use the best quality fixing and gaskets, many of them custom made to our own specification.