Scream And Fly Magazine - Mercury Racing's 450R (2024)

The Supercharged Super-Outboard That Has No Equal ▼

Fifteen years ago when Mercury Marine introduced the revolutionary Verado outboard, it not only signified a new approach to four-stroke engine potential, but it was also a bold insight into Mercury’s charted trajectory for future outboard engine development. Mercury was going to apply their engineering mastery toward developing new technologies, not just making existing outboard engine designs better, but by reinventing the four-stroke outboard entirely. The new Mercury Racing 450R is not only a stunning example of the culmination of that effort, but a product that is just as closely identified with all of Mercury Racing’s legendary race-driven history of defining what a high-performance outboard is. The 450R is simply an engine that has no equal. To put it another way, it is a lean, mean, dopamine-producing machine.

Back in 2013 when Mercury Marine began development on a series of all-new V6 and V8 four-stroke outboards, they set about dismantling the long-perceived penalties of owning a four-stroke outboard - excessive weight, costly and inconvenient maintenance, and of course, performance. In 2013 the idea that a four-stroke outboard could offer performance superior to the then-current high-performance OptiMax models seemed like a naive dream. The end of the OptiMax’s 20+ year run was fast approaching, and the anticipation of what would succeed it - if that could even be successfully accomplished - began.
The introduction of the 3.4-liter V6 last year represented a new generation in the design and performance for a four-stroke outboard; it is slim, very easy to maintain, and has impressive performance. Its angular, faceted design represented not only a new aesthetic, but a completely new vision for what a four-stroke outboard will be - a Mercury four-stroke outboard. This all-new engine design would ultimately spawn the new 4.6-liter V8 family of engines that completely upended the industry, most notably, the Mercury Racing 300R.

When I tested the 300R last year at Lake X, its incredible performance was such a dramatic departure from expectations that I was concerned that my report of its performance would not be believed. I had no doubt that the 250R and 300R would be impressive, but to the degree that they would leave their now-discontinued OptiMax counterparts in their proverbial wake in every measurable category? Indeed, it was to be a new era that the 300R ushered in.

The 450R’s development began three years ago, and I think it is safe to say that most of us assumed there would be a forced-induction version of the 300R. Mercury already demonstrated a mastery of the technology through its very successful Verado series, which was introduced in 2004, and so the 4.6-liter engine platform seemed destined for it, and indeed the engineers at Mercury Racing were doing what they always do - that is, not just creating new engines, but creating new performance standards.

The Mercury Racing 450R was

officially unveiled in Nashville, Tennessee at a very cool and appropriately-Music City restaurant called Ole Red in the city proper. Knowing that the press launch experience is almost as important as the product itself, Mercury Racing chose one of the coolest places I’ve ever attended, with live music and an electrifying atmosphere to match those monster engines covered in black veils. I set up my camera tripod and video rig in front of one of them. Would anybody notice if I took a peek? Very tempting, but I had to wait. I could swear I heard that big outboard calling my name. I had been waiting for this moment for over a year. If I had known that covered engine behind me was the cutaway display, my temptation might have gotten the better of me.

The next morning we took the shuttle to Blue Turtle Bay Marina on Old Hickory Lake. Before testing, I was wondering why Mercury Racing chose this location instead of Miami or another similar location since the 450R would primarily be used on big-water boats. But the press event is much more than just testing the engine’s performance prowess - it was about the entire experience of the product launch.

Once I stepped off the shuttle, I could see this breathtaking fleet of incredible boats docked and being prepared. Detailers were on the docks with towels and spray wax, keeping the boats pristine. The boats that were made available to us for testing would cover all aspects of what the 450R was really designed for - that is to say, high-performance boats that span the likes of the fastest to the most luxurious.
The new V8 has the kind of brutal power that us performance boaters are addicted to, but it is also very refined and designed to be very reliable and easy to own. Adding to that is the full compliment of Mercury's latest electronic technology, such as joystick control, Zero-Effort digital controls, and Skyhook, a GPS position-holding system. That comprehensive combination of performance and technology is really the key to what the 450R represents. It is a complete engine package that is just as high-tech as it is powerful, and yet the lightest outboard engine in its power class ever made.

From a technical standpoint, Yamaha’s 350-horsepower F350C 5.3-liter V8 outboard weighs 80 pounds more than the 450R equipped with the Sport Master gearcase - and it has 100 horsepower less. And while the F350C is not marketed specifically as a high-performance outboard, racing hulls aside, the F350C and 450R are designed for use on the same class of vessels that require very large outboards, and have comparable warranty coverage available. Furthermore, the 450R is based on the same 4.6-liter V8 as used in the new 300-horsepower V8 Verado, so the 450R is not an example of race-specific outboard that might otherwise be temperamental for consumer use. It is a high performance outboard that is just at home on the transom of a race cat as it would be on a sport fishing rig.

Over the previous decade we have seen four-stroke outboards slowly inch toward the two-stroke performance-to-weight and ease-of-ownership domain, but crossing that divide would require a leap of design and engineering that could not be an evolution of current four-stroke outboard engine designs. When you look at the 450R, it is astonishing to imagine that large-displacement twin-screw supercharged V8 engine is under that cowl. Interestingly, the long intake runners present on the 300R are not required on the 450R due to the nature of its boosted air induction, so that freed up space under the cowl where the supercharger and intercoolers occupy. Operating RPM range is a very broad 5800-6400 RPM, allowing a great deal of leeway for propeller and gear options.

Mercury pulled off some very very impressive engineering agility to package the 450R inside a cowl that is the same size as the one used on the 300R. Mercury Racing Director of Engineering Jeffry Broman explains:

“The biggest challenges are always in the details. For example, once all of the large parts (supercharger, intercoolers, oil cooler, bypass, etc.) are defined and fit in the cowl, we needed to design a wiring harness to fit in the space that was left and connect everything. Moving some of the rigging connections off of the engine and into the boat helped with that particular challenge.”

All of that is supported by Mercury Racing’s exclusive Advanced MidSection (AMS), which is designed to handle the higher torque and loads that this powerful outboard requires. The 450R AMS is based on the V8 Verado AMS, with the addition of more rigid mounts and heavy duty stainless-steel guide plates for added stability, and an optional integrated steering tie-bar mount.

The rules for performance four-stroke outboards have not only changed, they’ve been completely rewritten. This new series of Mercury’s V8 outboards represents a generation ahead in performance-to-weight and ease of ownership for four-stroke outboards.

Forced-induction engines of all types and sizes have a unique way of delivering power. You can always feel the rush of power as the boost pressure builds up, and to me, that is one of the greatest feelings a motorsports enthusiast could experience. I remember the first time I experienced the Verado back in 2004, how addicting that feeling was on even a very large boat. I had never experienced large boats accelerating so quickly and effortlessly. So I knew what to expect here on the Nor-Tech - or so I thought.

An electronic supercharger wastegate optimizes boost pressure for ambient conditions, and pressure-charging eliminates throttle lag, delivering torque when you need it. Indeed, the 450R actually has 40% more torque than its older stablemate, the six-cylinder 400R. Additionally, the 450R features Mercury's Transient Spark Technology, which automatically adjusts spark timing and fuel delivery to provide additional torque for a faster holeshot. And speaking of spark, the 115-amp alternator leaves no doubt that the 450R can handle the full compliment of digital control systems with a lot of power to spare for other electronics.

At its core, the 450R begins with what is already a beast of an outboard, the 300R. The 300R is naturally-aspirated, and its power is phenomenal, and the addition of 150 more horsepower would be an oversimplification of what the 450R really is and how it delivers its power. What I was about to experience on that Nor-Tech was something new.

Over the many years that Scream And Fly has been online, I have experienced and tested outboard-powered boats of all sizes and hull types. Back when we used an STV for product performance testing, going 125 MPH was something we did every week as a matter of routine. I won’t ever say I thought I had seen and experienced it all, but extreme speeds on the water is something I am very well acquainted with, and falling into the trap of forming preconceived expectations is very easy. But of course this is much more than just how fast a boat can go. Today, there are sport-fishing boats running speeds I would have thought impossible until fairly recently. Remember when reaching 100 MPH on the water was like breaking the sound barrier? Some of these boats can cruise at that speed.

Just cruising along at 110 MPH, those 450Rs were not breaking a sweat.

As we headed out of the marina, Trond wasted little time in getting the boat up on a step. Shortly thereafter, without any warning, he sent the throttles home and I suddenly reach for rear seat to prevent myself (and camera gear) from flying out the back. It was an occasion where I really could not adequately brace myself, and I couldn’t even hold my camera steady. From 40 MPH up to the mid-80s, the 450 Sport accelerated with almost frightening authority. Effortless sharp turns at speed nearly threw me around the inside of the boat as I held on to anything I could to keep from getting pitched overboard.

Trond knew exactly what his creation was capable of and he just calmly threw the 45-foot boat around as if it were a skiff as editors onboard clutched at seats and rails. I was completely unprepared for the onslaught of power and maneuverability, and I just couldn’t keep a steady footing during the chaos of changing G-forces inside the boat. And I loved every minute of it. This is a 45-foot sport-fishing deep-V boat, not racing tunnel. The hull weighs 20,000 pounds and holds 500 gallons of fuel.

Cutaway 450R on display at the press event.

Would you imagine a boat of this size and mass performing with the agility of a much smaller boat? Naturally, the Nor-Tech’s impressive agility is a result of its race-bred hull design, and being matched with the power to fully realize its performance potential amplifies the sum of hull and engine to a much greater degree. This would be the story for all boats present that day, and as we approached the dock, I saw Rick Mackie smiling as he read the expression of bewildered astonishment on my face, asking if I wanted to get on the MTI 340X. I thought he would never ask.

The 450R powerhead resides inside the same size cowl as the 300R.

The 340X is Mercury Racing’s own test boat, so it was dialed in to perfection. Like all MTI boats, the 340X is elegant, beautiful, and menacing. Its sweeping deck lines that converge to a taper at the stern give it an aggressive look that states its intention to go fast. It's a thoroughly modern design that combines the hard angles that give race boats their aggressive look, with some gentile curves to give the boat a sweeping, almost airfoil-like shape. This is a design trend I have been seeing on most modern cats for the last decade, and MTI has the formula just right. Lifeline vests were mandatory for this boat, and that alone built up the excitement to come.

Sport Master gearcase with five-blade CNC Cleaver.

With five of us aboard, we casually cruised around Old Hickory Lake. At 118 MPH. The one thing about the 450R is that like the 300R, from inside the boat it is surprisingly quiet, but out back it sounds ferocious. A few jet skiers tried to challenge us and were promptly left behind with a quickness. There is this overwhelming feeling that the engines were barely working hard at any speed. Throttle response is instant, and power is available in excess at any RPM.

Sport Master gearcase mounted to the Mercury Racing Advanced MidSection (AMS). The Racing AMS is based off the Verado AMS, with the addition of more rigid mounts, heavy-duty stainles steel guide plates, and an optional steering tie-bar mount.

Another boat present that I had to get on was the colossal Cigarette Tirranna 59. The only way to accurately describe this 3.4-million dollar ship is to say that it is extreme in every sense of the word. Six 450Rs gave the unapologetically sinister-looking, all-black Tirranna the same unprecedented display of torque to snap this 31,000 pound (without engines) hull to plane and a mid-70s MPH cruise in seconds. There is just something very attractive about the sound of so many engines harmonized in sound, pushing behind them this massive wall of rooster tails. Just glorious.

The slim profile of the 450R makes multiple installations very easy, even on narrower-beam boats. The Mercury Racing-specific AMS midsection incorporates a beautifully integrated steering arm, and it features rigid engine mounts required for precise handling for the speeds this engine is capable of pushing a high-performance hull. Indeed, the legendary SportMaster gearcase has been tested at 130 MPH.

Mercury Racing’s Digital Zero-Effort Controls can throttle up to six engines with just one lever. Joystick piloting is also available for installation of two to six engines, as well as Mercury’s Skyhook GPS-driven position-holding and autopilot system.

I had never been on a performance center console boat quite like the Tirranna, and being named “Six Karat” was cleverly appropriate. If the Death Star could be visualized in marine terms, this would be it. I never knew a 59-foot craft could move so fast and so fluidly. It was an unimaginably exhilarating experience that will leave me thinking about it for a very long time.

From the surreal Tirranna I needed to get aboard the Midnight Express 43 Open, which sat docked right next to the Cigarette. These two all-black monsters looked very out of place on the lake, and the attention they drew at the dock was a testament to that. The 43 Open has a similar configuration to the Tirranna, displacing 16,000 pounds and powered by five 450Rs.

By this time in the day I became familiar with the performance that multiple 450Rs bestowed on these very large boats, however the 43 Open surprised me with its feeling of lightness on the water and surprising maneuverability. It handled like a hull much smaller and lighter than it was, which was equally the result of its efficient two-step hull design, and the 450R's ability to maximize its potential. Speeds approached 90 MPH very rapidly, and sharp turns at 70 MPH were exhilarating and dry. To say that the 43 Open presented abilities usually expected in more race-oriented hulls would not be an overstatement.

I’ll close in stating that the 450R is most advanced high-performance outboard ever created. With the Mercury Racing V8 engine family now spanning 250-450 horsepower, they have nearly every size and type of outboard-powered performance boat covered. Will we see 500 or even 550-horsepower versions at Miami? I think we will, because with 4.6-liters of force-fed displacement, the 450R is only just getting warmed up.

The Mercury Racing 4.6-liter V8s not only represent a breakthrough in performance, maintenance and packaging, but a new generation. Suddenly, competitor's four-stroke outboards look outdated. This engine will make history.

Ten years ago many of us thought the true high-performance outboard would become extinct in a matter of years. Little did we know that the revolution in technologically-driven performance super-outboards was only just beginning.

Related links

• Mercury Racing 450R details
• Mercury Racing's YouTube channel
  
• Mercury Racing on Instagram

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