JBS K04 Cast Manifold  

Over the last 6 months JBS Developments has been busy working on a new cast K03 manifold, and now that the new K03 is heading into the final stages of production we have moved onto the K04 turbo application.

From what JBS has learnt from the development of the K03, the design process for the new K04 OEM performance upgrade manifold became a lot simpler.

Casting the new manifold gives better quality mass production and for such a constraint bound design as the K04 manifold casting gives fewer constraints on the pipe bend radiuses, allowing the runner to flow freely.  The most obvious improvement over the standard cast manifold being the increase in bore (diameter) of the runners all the way into the collector.

Like the new K03 design, the manifold has been designed in CAD to optimise the design, flow capabilities and to enable easier fitment. The CAD process allows the designers at JBS to manipulate the part quickly, while allowing information and measurements to be taken easily.

JBS K04 SPEC

The main work has taken place increasing the diameter of the runners all the way to the collector and the design of the collector to achieve best flow. The manifold has been designed to have maximum material around the bolt holes to prevent cracking, found on the OEM and competitors manifolds.  The collectors design also separates the runners to reduce port sharing of combusted gasses, aiming them towards the turbine in the turbo.

The box collector features cooling fins to minimise the effects of EGT’s on the manifold, preventing the manifold from warping and thermal fatigue.

Fitment of the manifold was also a large consideration, the area around the head studs and nuts was maximised to enable fitment.

The cylinder head flange uses the same design as the K03 to allow greater thermal expansion and movement between the runners. As it was found that a too restrictive flange forced stresses back through the runners of the manifold which lead to crack propagation.

Once we were happy with our design it was sent off for rapid prototyping to give us a physical model to evaluate before any design finalisation can take place. The rapid prototype is a highly accurate model taken straight from the CAD data.

The RP (Rapid Prototyping) gives a huge advantage in being able to fit the part to an engine and turbo, to test and ensure that the product achieves its specification. We are also able to physically flow test our design and compare it to our CFD (computational fluid dynamics) data before being sent for casting.

Recently there has been a lot of talk about performance manifolds cracking due to poor design, weak materials and the stress the manifolds are under due to high exhaust gas temperatures.  JBS JBS Developments are confident in the design of the new manifolds due to the hours spent on CFD (computational fluid dynamics) analysis and prototyping.

So to ensure the manifolds don’t suffer from poor material choice and casting quality, JBS has chosen to cast its manifolds in a very high quality foundry which is used by many OEM turbo suppliers and OEM vehicle manufacturers such as BMW and GMC to ensure the castings are of the highest quality.

Also to reflect the high quality casting; JBS has spent a great deal of time researching the latest high temperature resistant cast irons. These cast irons have a high nickel content, having the following properties makes them ideal for our performance manifolds: resistance to corrosion, resistance to oxidisation and high temperatures (up to 1050 ^oC), resistance to wear and erosion.

This is to ensure a minimal amount of thermal expansion and an equal rate of thermal expansion to the turbo housing, this again minimises the potential for thermal fatigue (cracking).  The bolts for the fitment of the turbo to the manifold shall be supplied as they are a specific size and material to prevent stretching which leads to blowing gaskets.

JBS Developments are now waiting for the pre-production sample to be delivered for a quality check and initial testing.

Once the first batch of manifolds are produced, they shall be thoroughly tested and dyno’d. At which time all power and flow figures will be released. Once all testing is completed and we are happy with the results we aim to release the manifolds at £470 including bolts and VAT.

We also have an IHI stage one/ Garrett GT28 cast manifold going into production and the K03 will be released soon.  As well as having our new range of tubular equal length manifolds for IHI, T2, T3 and Twin Scroll on sale now.

JBS Developments

We have now recieved the first sample of our cast K04 upgrade manifold:

JBS Developments

 The pictures show the best view of the whole manifold and show a slightly distorted view of some of the runners due to the angle the manifold has been cut through.

The runners have been designed to control the flow into the collector. The cross sectional area of all the runners is constant all the way up to the collector to direct the flow out "in" to the turbo, rather than "at" the turbo.

When designing the manifolds we not only had to look at the individual flow of runners, but also the space around the manifold and how it fits into the engine bay. If you look at a standard manifold attached to a turbo you will see the lack of space, meaning the options for increasing the cross sectional area of the runners are few, whilst also trying to keep access for fitting.

We will fit this sample manifold to our test car and hopefully have some real world performance figures for you soon.


JBS Developments

Hi All,

We are very sorry for the delay in supplying performance information for the JBS K04 Manifold.

We have finally managed to dyno the TT with the JBS manifold on.

The TT was dyno’d running a FMIC with no other modifications other than swapping the standard manifold for the High flow JBS k04 cast manifold.

We are very happy with the results, the graph shows the JBS manifold vs the standard manifold. As you can see from the graph we have achieved between 10-12Bhp increase in power and a 5% increase in torque across the rev range. With a very noticeable difference past 2.8k across the revs, this is due to the JBS design and concentration of eradicating port sharing and flow disturbance.

The manifold is showing excellent potential for running the JBS 05 turbo and with additional modifications like Forge TIP, Green Cotton Filter and sports exhaust, downpipe and sports CATs we think the bigger gains will be achievable.

We have also run the TT and manifold with a Phase 1 map.

We will get some peak figures up soon. We will also be testing the TT with the full stage 2 kit which includes the JBS 05 turbo.

After our initial testing of the standard K04 manifold we found that the manifold had cracked, with the fault lines propagating deep into the manifold, it had also split the gasket in 2 spots.

As you can see from the pictures these cracks are on the narrowest runner, that ports 2 and 3 share and they are due to the extremely high exhaust gas temperatures caused by the narrowing of the runners. The collector has also cracked due to the flows direction into the collector. The design of the JBS K04 manifold should help avoid these issues.

Regards

JBS Developments

Hi Guys,


Just thought I would give you an update on the ETA of our next batch of these K04 manifolds.

We are expecting a delivery in the next 7 - 10 days, so if you are keen for one, please let me know as they will go fast!

PM me, give us a call on 01246 455005 or get in touch via email at office@jbs.co.uk.

If you have any questions about the manifold, direct them my way also!

I look forward to hearing from you!


Many thanks


Kind Regards,

Jonny Close

Customer Relations Manager.