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I thought I may attack posting a little differently and share some technical development background information on some of the products we produce along with technical tuning techniques and validation testing we use over the next few months. But before I get into that here is a quick intro to both myself and Nizpro Marine.
As the owner of the business, you may be surprised that I’m still very hands on regarding product development and testing, it’s the area that I’m best suited to and enjoy the most.
My father ran a boat building company in Australia when I was growing up, so I've been actively involved in boating for well over 45 years. My main interested has always been engine development, and I was lucky enough to be at the right age when Electronic Fuel Injection and engine management systems were just getting started, mainly aftermarket systems, so much so, the very first MoTeC EFI systems I tuned were screwdriver adjustable. Over the next four decades I have actively watched, learned and calibrated many top-level engine management systems along with designing forced induction systems ranging from single to quad turbocharged engines, and of course one you may be familiar with, the Nizpro Yamaha V6 supercharger system.
So why Yamaha?
Well, I guess like many of you, we can trace our love of a brand back to your early days growing up. With me, my first Yamaha product was a Yamaha YZ80H motocross bike, then in 1984 I was old enough to get a road bike license, and the bike of choice was a Yamaha RZ500. So yes, I started with 2 bangers. I did during this same time have several 2.4 V6 Mercury’s on the back of boats dad and myself laid up, but when the Yamaha 225 Excel came out around 1988 from memory, I quickly ditched the Mercs and fitted the Excel to a 17-foot mono that ran 89 mph. It was bullet proof and from that time on it just had to be a Yamaha.
| Nizpro Marine Supercharged Yamaha 450s |
By 2010 my young family was now old enough to head back to the lake I grew up at and so I needed a new social boat. I purchase a new F19X Force, (19 foot ten inches) built out of Sydney NSW, these were the go-to boat for going fast in average water and we had campaigned a 21-foot version for some years that was fitted with a 4.5 litre twin turbo charged Nissan V8 engine that ran 126 mph with skiers so I knew them well.
Now for the engine decision. The Yamaha 4 stroke SHO was released 2008 in the US but in Australia we still didn’t have them here, so it was a weigh up between the 300 HPDI or trying to import a SHO from the US. I finally tracked down a dealer in the US that would ship a SHO to me, however it was only a 225. Fast forward, it turned up and off I went for the first blast and 76 mph was it, bitterly disappointed, I knew at that point it was clear I need to hack the ECU and start tuning. A year later and the boat was now doing 93 mph, and in August 2011 while doing further testing and me being a dick and not paying attention to anything but the incoming data and speed, the boat left the water and headed for the sky.
For the next couple of months while now driving around in a wheelchair I decided what the engine really needed was more power, this was a hard sell to people close to me, but I figured if you have enough engine power like the twin turbo 21-footer, I wouldn’t need to fly it like a kite to get the last MPH. You know where this is going!
| 100+ MPH Force F1 Equipped with Nizpro Marine 475s Supercharger System and Nosecone |
Enter the Nizpro Supercharged Yamaha 4.2 V6, but that is a development story for another day if you are interested, I’m going to start with some great information on the development, results and testing of our new Yamaha SHO and Offshore V6 nose cone we have finished.
Here at Nizpro Marine we are always looking for ways to improve the performance of your outboard engine and boat setup. While nose cone extensions are not new for Nizpro Marine, we felt that the exiting design and installation method could be improved upon significantly.
The key design goals for our latest release included:
- Reduction or elimination of welds to install the nose cone extension.
- Reduced hydrodynamic drag.
- Improved high running position engine water supply.
- Improved steering accuracy and response.
By utilizing the latest in 3D scanning technology, Computer Aided Design (CAD), and Computational Fluid Dynamics (CFD), we were able to achieve all of these design goals.
What we came up with is a single-piece design, of cast alloy construction, with the following key features:
The contoured mounting surface serves two purposes. The first is to ensure accurate alignment and fitment, which minimizes the amount of post-fitment work needed to smooth the transition from the nose cone extension to the main leg. In addition, the specially designed contoured surface also allows the use of high-strength epoxy adhesive, removing the need for expensive and complex welding procedures and the risk of deforming the lower bearing carrier during welding, making installation a breeze.
In order to validate the use of high-strength epoxy for installation several tests were performed. Starting with CFD analysis, the nose cone was run through various simulations from semi-submerged, to fully submerged, and at boat speeds of 50-100mph in 10mph increments. These initial simulations were at a steering angle of 0° (straight ahead), and provided several important pieces of information:
- Internal cavity water pressures.
- Straight-line drag forces.
- Lift forces over the nose cone surface area.
By investigating the internal cavity water pressures, we could gain a better understanding of the effectiveness of the low water pickup design. Our simulations showed a peak of 9 bar (130 PSI) at 100mph which guarantees, at higher boat speeds, that the engine will receive a steady supply of cooling water.
This helps to prevent aeration in the cooling system, and localized boiling, which can be an issue in setups with raised engine heights running the factory water pickup methods. It is one of the reasons why you see some 4.2 V6 cylinder heads develop cracks in the cooling jacket.
The images highlight the lower pickup and water entry into the cavity that ultimately feeds the water pump.
Straight-line drag forces are simply the forces exerted on the frontal area of the nose cone when moving through the water. A comparison of the factory nose and the Nizpro nose cone extension was performed at a simulated speed of 50mph under fully submerged conditions.
The Nizpro nose cone extension outperformed the factory design, reducing the force on the frontal area by 16.4%.
With the low water pickup design, engine heights can now be raised, which further reduces the frontal area forces when compared to the factory design. At 50mph these forces reduce by as much as 56%, which leads to an improvement in fuel economy at cruising speeds and improved top speed figures under full-throttle operation, all things being otherwise equal.
| Nizpro Marine AMT 30 offshore cat powered by twin supercharged Yamaha 4.2-litre engines |
Lift forces are a function of boat speed and surface contour design and are determined by analyzing the average surface pressure over the entire nose cone area. These tests were performed to gain an understanding of the forces generated by the nose cone to allow boat owners, when setting up their boats, to know the amount of bow or stern lift when running the engine at various transom heights and speeds. These tests also allowed us to understand the forces the epoxy adhesive would need to withstand during straight-line running.
Shown below are two of the graphs produced, illustrating the lift forces at different speeds for a fully submerged Nizpro nose cone extension versus a Nizpro nose cone that has the water line through the centre of the torpedo (50% submerged). Positive values indicate lift.
Bow Lift
Stern lift
This testing showed a peak of 60kg (132lb) lift force at 100mph.
To further understand bond strength requirements an additional simulation was performed at 100mph, but with the steering angle set to a 5° Slip angle. This test aimed to simulate steering input at high speed and allowed us to understand the side-loading on the nose cone during a high-speed manoeuvre. The resulting force was 400kg (880lbs), and this information was noted for physical testing purposes.
With the CFD analysis complete, real-world testing was undertaken to validate installation and epoxy bond strength. After installing the Nizpro nose cone extension a point load at the cone tip was applied, up to 450kg (~1000lbs) in the following directions:
- Vertically upwards
- Vertically downwards
- Sideways
The epoxy bond performed flawlessly in all test cases.
Also considered in the design was the requirement to access the oil drain plug. The outer surface of the nose cone is CNC machined to provide access to the oil drain plug and finished with a 16mm, threaded and anodised, oil drain access plug, to maintain the outer contour for normal running.
A CAD designed oil drain plug retention insert was designed and provided in every kit, which is installed prior to fitment of the nose cone extension. This takes up the space between the original surface of the lower unit and the inner surface of the nose cone and prevents dropping the oil plug between the two.
This aids in the alignment and installation of the factory oil drain plug during servicing.
The Nizpro nose cone extension system comes ready to install with full instructions and includes:
- Alloy nose cone extension.
- CAD-developed skeg cutting template.
- Oil drain bolt retention insert.
- Epoxy adhesive.
- Epoxy putty spatula’s.
- Billet anodised 16 mm Oil drain access plug.
- Installation instructions.
Regards Simon
Nizpro Marine
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