Turbo 2+2 "vs" Turbo Ultima

[MOP]

I finally got to do a back to back test of a newly acquired 22" Turbo 2+2 against my 23" Turbo Ultima, I decided to try the 2+2 as it is suppose to have more bow lift then the Ultima. Surprisingly both props turned the same WOT RPM within a hair of each other, mind you a 22" "vs" a 23". As far as handling at various speeds the 2+2 did a very good job compared to teh Ultima which is to say the least great! The 2+2@5100 63.6, the Ultima at tight on 5100@65.5. The 2+2 blades have more cup and also look thicker, that could well be the reason for the close RPM but the lesser speed. A little background the wheels I tried was a Mirage 21" 63@5350, 23" Merc 3 Blade cleaver 65@5150 flat, 23" 3 Blade Mirage 65@5100 and the 23" 4 Blade Ultima 65.5@5000. As my RPM came down the speed went up, which proves what many have said it is not the RPM you turn but it is getting the engine onto its RPM band.
I know Mr. Frclarke must be wondering why I have been dragging my feet on this one, he was the first to test my 2+2 on his 18, though it was not enough pitch it woke his boat up big time it was the fastest it had ever gone and did a great job of taming the handling. I wish I he had tried the Ulitma!!!!!

Phil

[BigGrizzly]

Thoes props arn't even close to each other. The pitch progression are totally different as is the diameter. The speed is due to the pitch progression which has less slip. Frclarke is now running a 23 OSI which is a superior rough water prop. When you do a prop test to compare do speed vs RPMs this will let you know where one faults and another shines. as for the top speed difference a 22 vs a 23 at the same RPMs the 23 should be faster--more pitch- more speed. The Diameter and number of blades also play an important role here also

[MOP]

Randy you need to help me out a bit, both props are the same size and number of blades. They have a different blade configurations, cup and pitch as shown below. I know you can make better sense out of my testing then I. What got me was the 2+2 being a 22" that will not spin up higher RPM then a 23" and is considerably slower then the Ultima at almost identical WOT RPM. That tells me the design is not near as good for my application as the Ultima am I wrong? You and I did a little back and forth when I got the Ultima, you made a point of telling me what an excellent rough water prop it was which it has proven itself time and time again. I do not know how the 2+2 is in the rough, the testing was done in a 1' chop, from the hour and a half I spent swapping and testing the Ultima is far superior in every respect. The 2+2 will make a pretty spare.

Phil

[BigGrizzly]

The 2+2 was not designed for your application. It was mad for shallow v small outboard runabouts in moderate chop. It has a good hole shot but I believe the cupping id too much for that particular blade design. The Ultima and OSI were designed for bigger offshore applications. The pitch progression and specific boat lifting characteristics and rake were built in to these props. In short the 2+2 is a decent prop, but not as as the newer props for the newer bigger powered boats. What you will find i the bigger power and heavier modern boats need a more aggressive rake and pitch design. It is hard to describe, but you are finding this out by your own testing, your just wondering why. Take the Ultima and @+2 and set them on the bench side by side, write down the separate attributes, do not compare yet, and place them by the respective prop. Look at the props and then compare and with your past experience you will begin to understand. If you get stumped you can give me a call and I will help you out.