Nizpro Nissan RB30 Intake Plenum

Nizpro designed its first intake plenum back in 1988, this was to suit the Nissan RB30 Turbo engine fitted to the Holden VL Commodore. The VL Commodore was really the first vehicle that was fitted with a large capacity fuel injected turbo engine seen in Australia. In many ways the RB 30 engine lay out was similar to the Ford BA Turbo. The throttle body was located between cylinders 3 and 4 and aimed across the rocker cover. This suited the non intercooler engine design well.

Although modification to turbo charged EFI engines was still in its infancy it quickly began apparent that the need for intercooling engines was of paramount importance. Repositioning of the throttle body to the front of the intake manifold was a logical set to accommodate the shortest possible pipe work from outlet of the turbocharger to the manifold via a front mount intercooler. However after many hours engine dynoing this modification it was proven that the stock modified intake manifold was certainly causing issues with even flow distribution.

Above: Nizpro RIT RB30 Plenum

We quickly decided a complete new plenum was needed and set about designing a completely new alloy casting that attached to the lower standard manifold. The standard Nissan lower manifold had different length runners, so the new Nizpro version adjusted these lengths internally within the plenum using alloy spun trumpets at various lengths. The top and lower section patterns were produced in house. In the first prototypes the top and lower sections were bolted together, this allowed removal of the internal trumpets so various lengths could be tested on the engine dyno. Once we had established the correct length production versions were now welded together. We left the casting unmodified from the original prototype and simply added bolts into the blank holes in the finished version.

The Nizpro RB30 intake plenum known at the Nizpro RIT {RAM INDUCTION TURBO} worked fantastically due to countless hours spent on the engine dyno perfecting its design. For the next ten years it was firstly the only plenum available and every record holding VL Turbo had one fitted, they have become very sort after since Nizpro sold the patterns and production stop in around 2000.

Nizpro Ford BA XR6 Turbo Intake Plenum

In 2002 and the introduction of the Ford BA XR6T started the complete process all over again, from the original years and design of the Nizpro RIT RB30 plenum till 2003 we had designed and manufactured many new performance plenums to suit one off racing application, however the BA Falcon Turbo called for an improved design that required Nizpro to produce a high volume production replacement as the standard unit was showing all the design issues of the RB 30 design of some 17 years earlier.

Above: Nizpro Cobra Plenum – Ford BA-BF engine

To tackle what we believed was going to be a far higher production rate we decided that an easier to manufacture design was necessary for the Barra engine. The RB30 plenum required many hours of hand assembly. With the purchase of a brand new Ford BA XR6 Turbo along with two complete turbo Barra engines for engine development work, the Nizpro Ford intake plenum project began. The car was initially used for measuring engine bay dimensions and allowed us to make sure that fitment was as easy as possible while included all necessary parts that were going to be required for fitment of a front facing throttle body design plenum. One engine was delivered to our pattern shop to start the work on producing patterns. Unlike the late eighties when we developed the RB30 plenum we now had our own designed and built in house engine dyno, the second engine took up residency on the dyno for all testing work to commence. Very similar to the original RB30 version a mock up hand fabricated version was produced for testing. All original testing was done with the turbocharger removed, this eliminates boost and air temperatures differences effecting power results.

Above: Nizpro Cobra Plenum Installed – Ford BA-BF engine

Theoretical designs were tested first and then modified before settling on a plenum that offered both faster throttle response along with a naturally aspirated power gain on 21 engine kw. With boost reapplied less turbo lag, fastest positive pressure response and a 37 kilowatt gain at 15 psi boost pressure. The project was then turned over to the pattern makers to finalize production tooling. Just like the RB30 plenum the Nizpro designed and manufactured BA-F Falcon turbo plenum has lead the way with most of the fastest and most powerful XR6T’s having them fitted for over ten years.

Nizpro Ford FG Intake Plenum

Introduction of the FG in 2008 meant back to the drawing board, the FG now had a one piece intake manifold including the plenum and throttle body flange. This meant a far more complete design was needed and would also require the manifold runners and fuel injector mounting.

Above: Nizpro Cobra Plenum – RAW after casting – Ford FG engine

Once again the purchase of a brand new vehicle was needed, this time a FG F6, Nizpro secured the forth car off the production line and immediately set about lifting the bar even higher with a new complete intake manifold and plenum. This ended up the most costly development Nizpro had taken on in regards to a single component. The first issue we ran into was the excellent job that we had done back in 2002 on the BA left us struggling to make a performance gains over the original that we were using as a base line. It became apparent we would need to go back to the future and use the same design as the RB30 plenum and use free standing individual trumpets. This time we cast the trumpets as a set of six. We also wanted to design in an option of six individual throttle blades. These added throttle blades closed off one of the intake ports on each cylinder. This effectively doubles the air speed down to one on the two intake valve per cylinder and complemented Ford’s new cylinder head chamber that was effectively adding twirl as well as tumble to the intake charge.

Above: Nizpro Cobra Plenum – Ford FG engine

We also wanted to make the complete manifold bolt on without the need for relocating the battery and air box and still being able to run the factory intercooler. Mechanically speaking the manifold was outstanding, off boost performance was night and day over the standard FG turbo manifold, the engine was considerable smoother at idle and economy was also improved. The down side was cost, production times to cast, machine and assemble tripled, and with Nizpro making the most efficient intercoolers and exhaust systems possible for the FG peak power was now limited by the turbocharger size, so peak power while using the stock turbocharger was only around 15 rwkws.

Nizpro FG Intake manifolds are for the perfectionist there is only produced at time of order.

Nizpro VRH60 Intake Plenum

The future of intake plenums and manifolds looks to be heading down the Carbon fibre path. In 2009 Nizpro began development of their VRH60 V8 quad turbo ski race engine. The design brief was for a light weight 1500 hp endurance engine. One measure to achieve this was the development of a light weight intake manifold and plenum.

 Above: Nizpro Carbon Fibre VRH60 Plenums

The V8 engine design requires both a left and right intake plenum so the weight savings were to be doubled. Using the same techniques we set about planning, design, tooling and production of the Carbon Fibre intake plenums and magnesium intake manifold. The carbon fibre allowed super light weight but still allowed boost pressures of 45 psi well beyond the required pressure to achieve the horse power target. Thirteen pieces in total make up the V8 intake system. It was also developed using the engine dyno testing in naturally aspirated form and used prototype intake runners to adjust lengths to optimize our target power range.

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