[Putershark]

Wood,

I venture to say the with the Prop surface area being equal, and at the speeds you are traveling, 4 versus 3 bladed props "might" (for I know of some guys who just fly with 5 bladed props) shave off a knot of top end speed. Here again, how many props can you adjust the pitch on? Drop it back one notch if it is killing you very badly which is pretty easy to do with a Prop Pulse (go view their web page) model.

They do though (4 blades) equate to a much smoother engine (remember you cannot divide a circle equally by 3) and better bite both low end and for cruising performance. Mid range performance to me is much more important at $3.00 plus a gallon fuel than raw top end speed anyway. Your performance though is not linear when it comes to fuel burn rates and engine trim, weight in the hull, water conditions, speed to plane (meaning how fast you punch her to get the hull to plane) all play major factors in range. Come on down some time, and I will take you for a ride in my 190 that has all digital gauges with fuel management and see just how little trim, height, and RPM changes can make a big difference in “real time” fuel burn rates.

Let us not forget though that if you really want raw top end speed (not a Triumph's hull strong suit) then you really need a Stainless Steel prop. The Pro Pulse prop though is both stronger (less flex) and lighter and any aluminum prop so I would consider it a good "middle of the road" choice that is hard to beat for the price point. If nothing and after you get the pitch all dial in, one could always go buy another model of metal prop and store it as a back up unit that will never rust...

Another thing many forget is when it is all said and done and you have had that metal prop on your output shaft for a year or more on your saltwater boat and need to take it off… Just let me know how much fun (or fuel you burned in your torch ) that you had in trying to remove it! Ha-Ha…

I also do not agree with the assumption the all cavitation plates kill top end speed. Now if you have one of those huge plastic models that look like somebody mounted the port wing off of a B52 Bomber onto their lower unit… Then yes, that much lift and drag could do such. So study the various model very closely looking at the the wing design before buying one is my best recomendation.

Engine trim angle though (and many forget such) becomes even more powerful if you have a one of these lift devices mounted on your engine. You do not need to use as much running trim (much less trim period) as before OR you can create a lot more drag. Remember as a kid how your hand went flying up or down when you greatly changed the “angle of attack” when you stuck it out the car window at highway speeds? Now double or in some cases triple that same surface area (like flaps on an aircraft wing) by mounting one of these devices on your lower unit and hopefully you can picture in your mind the possible negative effects from using the same “amount” of trim as you used before it was mounted.

Hope this helps some?
Dave