Skater30

We will all get to see how 450 cats do against light powered inboard cats next year when the new 450R outboard class is up and running. The Super Cat class is running single carb, 750hp motors - comparable to Merc 700s with Whipple kits. Boat sizes will be similar as well, so it will be interesting to see the average speeds for each class. I will also be sure to get some video this Summer when running with my two buddies with 450R rigs - one with a 368/450 setup and the other with the 340X/450 setup. No doubt in my mind that the 450 boats are going to kill me from a 5 zone to 100, but I think from 100 on up the outboard acceleration advantage will disappear.

Bullhead

The numbers that the Victory hulls have put up are very impressive....they were the class of the field at the shootout....I do find it interesting that they don't seem to have the same speed advantage on the race course as they do in their pleasure versions

Skater30

Race classes have a minimum weight, pleasure boats don't. When the boats are all equal weight/length with equal power, the Victory hulls don't have an advantage in speed (obviously, or they'd be winning). Victory built an extremely light pleasure boat, that's why the one that went 141 is so fast. Wait for the first bump that Victory hits at 140 though and see what happens, I guarantee it won't be pretty. There's no magic to any of these modern outboard cats, they're all very similar. It's simply a matter of power to weight. For example, my 2005 Skater 30/400R rig weighed 5,400#s fully rigged, dry. The latest DW32/450R rig weighs only 4,700#s fully rigged, dry. I was told this weight by a friend having one rigged at Grant's right now, so I can only take this as truth. It doesn't take a rocket scientist to figure out why these modern outboard cats are so fast - they're extremely light.

lavey jr

Whats your definition of speed advantage?
Meaning, on which racing circuit? The way I see it, they dominate on their home turf where they test and test and test. On that field they even beat the US based boats that race there. In more recent times since they’ve been coming to the US circuit, they’ve been racing against teams that have been racing here for years and years and years that have basically everything dialed in for all the conditions here. Whereas the Victory boats are “new” to the scene here. That’s just my opinion.

So your 30/400R weighs 5,400 and the DW32/450R weighs 4,700 fully rigged. What’s your definition of weight for the Victory being an extremely light pleasure boat? Is it more than your 30 or less than the DW32? Let’s all keep in mind the Victory is 4-6’ longer than both boats so if it weighs more than your 30 then that’s understandable, but if it weighs more than the DW32 but less of a length difference compared to your 30, then at what point does added length make a positive difference to speed vs the length gap? Or, what if it weighs the same as your 30 but is 6’ longer and still runs faster which at what point does 100hp total difference make up for that speed increase for the Victory?

Skater30

I wasn't comparing my old 30 or the new 32DW to the 36 Victory, I was stating the weights of the two similar sized boats (old vs new) to show how much lighter the new generation of outboard cats are. I don't know what the 36 Victory weighs, but I'm certain it's lighter than it's competitor's boats that are similar size - 36DW, M37R, 390X. I've talked to two separate industry outboard cat guys (one of which has driven the 141mph Victory 36), and they both told me it is ridiculously light. Kudos to Victory for being able to build a boat that size so light, and they're rewarded with the fastest outboard cat on the market. But I will hold by my original premise that the reason for these new generation outboard cats (not just the Victory) being so fast is primarily the ultra-light weight of the fully rigged boats. Put each of the aforementioned 36' - 39' cats on a scale and make them all meet the same minimum wet weight (let's just call it 6,000#s), and I'm certain you'd see the speed differences narrow significantly between them. That is why there is such parity in the Stock Class, and why it provides some of the best racing on the course - equal weight, equal size, equal hp = similar speeds and close racing.

SinOjos

Interesting that aerodynamic drag is rarely or never mentioned. Never seen any wind tunnel tests, yet standard with autos, motorcycles, aircraft & everything else, including bicycles that get no where near the speeds that boats are seeing. Bicycle racing aerodynamics have changed every aspect, clothing, helmets, glasses, shoes, spokes, wheels, tires, frame tubing, etc. Aerodynamic advantages at 25-45 mph on bicycles has been proven. Some bicyclist & swimmers shave their body claiming hair causes drag, yet some aircraft utilize vortices to increase and decrease fluid flow velocity, some of which are similar in some cases to hair protruding from skin.

There are many devices that are used on aircraft to induce and or reduce drag and or lift, in the case of stol aircraft, control air flow at a high angle of attack at slow speeds increasing lift while avoiding a stall.

Wind resistance increases significantly as speed increases, at higher speeds aerodynamic efficiency plays a greater part than simply weight. Considering that catamarans are aircraft, why does no one mention aerodynamic drag. I am sure the designers have been using wind tunnels, or at least computer programs to improve aerodynamic (fluid dynamic) efficiency. Yet, never seen anything published, must be the we do not want to give up what we know to the enemy. Yet Bernoulli's principle is well known & taken advantage of affect in all mediums of transit. It is not weight and or horsepower alone at the speeds these boats are running.

Catamaran blow overs do not seem to be as common as they once were, yet the numbers in use has increased substantially. Therefore aerodynamics must be playing a much bigger part than is being disclosed and or discussed.

With two different boats, weighing the exact same weight at rest, depending on their lifting surface, parasitic & induced drag, providing for a total drag at a given speed. Two boats of a different shape, will not weigh the same at a given speed, nor will they both go the exact same speed with identical power. Two boats, cars, motorcycle, airplane, anything, due to slight differences, variance in manufacturing, will never be exactly the same, even though built to be identical. As technology has improved, those variances have diminished, yet they still exist enough to make a differance.

The balance of lift and or down-force in some cases, parasitic & induced drag is having a big impact on performance. One constant is aerodynamic drag, look at cars, specifically SUV's, they all look the same. One shape works best. Look at all the catamarans, they for the most part all look the same. It is getting to the point that slight nuances in aerodynamic performance is going to be the defining difference in over all speed. Not withstanding the individuals throttling & steering. Yet, one design in a headwind might perform better while another might be better in a crosswind or tailwind. Nevertheless, outboard catamarans, are being defined by aerodynamics, not only weight, horsepower, fluid dynamics.

I know I am not saying anything that many are not aware of. But it is something that is rarely discussed. Nobody mentions how the strakes affect aerodynamic efficiency or provide lift, or induces vortex. Strakes are used on many aircraft. An 1 inch or 1/2 inch strake sticking out makes a lot of difference at 130 mph, is the edge sharp, or is is curved or cupped? STOL aircraft operate at much slower speeds, slight differences make a big difference. How many of you have stuck your arm out of a car window or boat, unobstructed airflow at 130, not like flying yer hand at 50-90 mph going down the highway!

https://en.wikipedia.org/wiki/Drag_(physics)
https://en.wikipedia.org/wiki/Bernoulli%27s_principle

lavey jr

Agreed. You make all valid true points. I was purely just wondering.

caseyh

Why have we not seen any O/B cats with trips like the old days but with the 300/400/450s

Twin O/B Sonic

I heard the new v-12 Mercs ran 150 in testing on I think a 39 something......

BTW, ugliest motors I’ve ever seen!

Lake rat Skater

Because with cats the center engine takes a major beating and you run into problems with the lower unit. The third motor would provide more acceleration and a little more top speed but most feel the additional cost and potential head ache are not worth it. After twin engines on cats you get into diminishing returns adding additional motors. Also it would need to be one of the bigger cats to be able to handle the additional weight. With all that said I do believe Skater has a new 38 in the works to be setup for three 450s. Maybe the speedonthewater crew could get some updates or do an article on it?