Props to address Cutwater performance

Almost Free compared to the $5K Sharrow props (tried several pairs), about 1/5 the price and I was able to get the performance I was looking for with PowerTech.
 
I picked up my five blades yesterday for $ 2,200 with tax. I did not get the exhaust tubes. Eager to see how the NizPro economy tune and 5 blades impact performance and economy. I will post results in a few weeks,,,,
 
Lrob32CB said:
I picked up my five blades yesterday for $ 2,200 with tax. I did not get the exhaust tubes. Eager to see how the NizPro economy tune and 5 blades impact performance and economy. I will post results in a few weeks,,,,
Click to expand...

What 5 blade prop did you go with?
 
Power Tech, 16p, 15.25 diameter
 
Lrob32CB said:
Power Tech, 16p, 15.25 diameter
Click to expand...

This will be a good test of performance then.

The NizPro tune gains are apparent the faster the boat goes in my experience. My best fuel efficiency gains with NizPro are approaching WOT.
The Yamaha stock tune had my WOT at 39mph, 27.2gph, at 5700 RPM. NizPro tune resulted in the same, except GPH maxes at 24.2gph. I burn 3gph less at WOT for the same speed and RPM as before. Mid-range performance with NizPro is supposedly single digit gains. I don't even know if my numbers will show a gain in mid-range to attribute to the NizPro tune. But the PowerTech prop with the exhaust tube extension makes a big difference in the mid range. The 5 blade without the exhaust tube would let me run in the mid-range.

The exhaust extension provides fuel efficiency improvements in the mid-range specifically, while improving hole shot and reverse (for docking). This allows me to operate at pretty much any speed to match the sea conditions. The NizPro tune I am seeing performance (fuel efficiency gains) on cruising speeds to WOT.

On us single engine boats, the mid-range is 3000-4000 RPM, doing 12-18 mph. Cruising is 19mph-39mph (WOT).
The boats with Twin F250/300's, their mid range speeds is my cruising speed.

There's two NizPro tunes to choose from. Their performance tune (332HP, 89 octane) or their eco tune (315HP, 87 octane). I am running the NizPro eco tune.
Here's the graph.

Performance Tune
C102167A-B511-47D8-8C23-F6E4DA0CADF0_4_5005_c.jpeg


Eco Tune
82324EC9-5800-4F9B-BD31-404F60C56E19.JPG
 
Propeller selection can significantly affect a boat’s speed, fuel efficiency, and overall performance. Comparing propeller designs and testing different setups can help identify the best configuration. For broader engineering insights, explore what do aerospace engineers do: https://hydrasearch.com/what-do-aerospace-engineers-do/
 
I had the Power Tech Channel Surfing Edition (16p, 15.25 diameter) propellers installed in my Cutwater c-32 last week.
My many thanks to @Submariner for helping me through the process. It took quite a while to get my Power Tech propellers.
The wait was worth it.
So far my testing is only one hour so too early for a lot of final observations.
My goal was to be able to cruize at 25 knots covering 1 nm per gallon (of marine fuel - alcohol free).
With the original Yamaha 300 propellers I was getting 0.85 nm per gallon when cruizing at 25 (the boat would not plane below 28 knots).
However, I had to slow down for extended periods of time here in the NorthWest during peak sailing season (to be safe) so 25 knots was quite often the maximum speed I could achieve.
So far with the Power Tech propellers I observed 1.15 nm per gallon when cruizing between 24 and 27 knots. I am very pleased.
Before with the orignal propellers, I had to be cruizing between 32 and 34 knots to get the same economy.
That was way to fast for me. I was always concerned with traffic in the San Juan and logs in both Puget Sound and the San Juan.
And the speed was also a problem whe going through the Canadian Gulf Islands. With the tensions with Canadians, I did not want to offend anybody.
I did notice that myconsumption with the new propellers deteriorated a bit when cruizing at 32 knows. I now consumes closer to 1 nm per gallon between 32 and 34 knots.
I'll be posting more precise numbers once I have a chance to travel more extensively next summer.
 
ucarrasquilla said:
I had the Power Tech Channel Surfing Edition (16p, 15.25 diameter) propellers installed in my Cutwater c-32 last week.
My many thanks to @Submariner for helping me through the process. It took quite a while to get my Power Tech propellers.
The wait was worth it.
So far my testing is only one hour so too early for a lot of final observations.
My goal was to be able to cruize at 25 knots covering 1 nm per gallon (of marine fuel - alcohol free).
With the original Yamaha 300 propellers I was getting 0.85 nm per gallon when cruizing at 25 (the boat would not plane below 28 knots).
However, I had to slow down for extended periods of time here in the NorthWest during peak sailing season (to be safe) so 25 knots was quite often the maximum speed I could achieve.
So far with the Power Tech propellers I observed 1.15 nm per gallon when cruizing between 24 and 27 knots. I am very pleased.
Before with the orignal propellers, I had to be cruizing between 32 and 34 knots to get the same economy.
That was way too fast for me. I was always concerned with traffic in the San Juan and logs in both Puget Sound and the San Juan.
And the speed was also a problem whe going through the Canadian Gulf Islands. With the tensions with Canadians, I did not want to offend anybody.
I did notice that myconsumption with the new propellers deteriorated a bit when cruizing at 32 knows. I now consumes closer to 1 nm per gallon between 32 and 34 knots.
I'll be posting more precise numbers once I have a chance to travel more extensively next summer.
Click to expand...
 
I have a C302 as well with the same problem. So the OFS5-16-EXT is the recommendation for best performance at 25kn?
 
Yes, read through the thread. There's lots of detail and I posted numbers for my C302c. The OFS series is different than what was used for the Ranger boats. This prop is needed to provide ample stern lift that the Cutwater's are plagued with.
 
WWIProps said:
I got a hold of the receptionist at the PowerTech front desk and she put me in touch with John Parker who was very helpful. I have a Cutwater 32CB and just installed the OFS5 CSE. I am not quite ready to publish my data as I have not had a really smooth day to properly compare the new props to my factory setup data. Preliminary results shows my performance is pretty much in line with Mike and Sarah's Solara 31 data. I have lost about 3-5mph (51mph down to 47mph) off of the top end speed and have seen significant efficiency gains around 42-4400 rpm. The hole shot is great and I get on a plane around 3400 rpm/21mph/.96gph. I cruise at 4200rpm/33mph/1.2gph. I am surprised the counter rotating prop (starboard) engine is burning more fuel in the midrange than the standard rotation (port side) which did not present with the original props. The WOT and below 2500rpm fuel consumption is the same on each engine. The boat seems to run flatter with the new props. Again, I need to do some more testing with slack tide and smooth water.
View attachment 27662View attachment 27663
Overall I am very pleased and I recommend the upgrade.
Click to expand...
i have a C302 with factory props and the starboard F300 always used about 6% more fuel.
 
Jclima said:
i have a C302 with factory props and the starboard F300 always used about 6% more fuel.
Click to expand...
We found on our Solara 310 with twin 300 the starboard engine burned 1-1.5 more gallons per hour. Until we figured out if we trimmed the starboard engine up 1-2 bars higher than the port engine. Both are within .3 gph now.
That was with stock 3 blades and OFS5 blades.
 
Interesting. I wonder what happens if you trim the port side up the same amount if you would also gain that much more fuel economy. you prob just making your port motor work a bit harder by being trimmed lower no?
Mike and Sarah said:
We found on our Solara 310 with twin 300 the starboard engine burned 1-1.5 more gallons per hour. Until we figured out if we trimmed the starboard engine up 1-2 bars higher than the port engine. Both are within .3 gph now.
That was with stock 3 blades and OFS5 blades
Click to expand...
 
Rocky Lou said:
Yes, read through the thread. There's lots of detail and I posted numbers for my C302c. The OFS series is different than what was used for the Ranger boats. This prop is needed to provide ample stern lift that the Cutwater's are plagued with.
Click to expand...
I just sent John an email to see how much and the lead time on those are. Maybe I’ll get them for Christmas. 🙂

Here is what I’m getting currently on factory props:
IMG_0020.jpeg
 
Jclima said:
Interesting. I wonder what happens if you trim the port side up the same amount if you would also gain that much more fuel economy. you prob just making your port motor work a bit harder by being trimmed lower no?
Click to expand...
With the 5 blades we start at 3 bars up on both motors then add one to two more on Starboard. If I try and raise the port to match the starboard fuel burn doesn’t really change but speed might drop .5 mph. So I don’t really feel we are working port any harder.
I really don’t have any idea why but that is what we have found. With 3 blades it was the same except we started with both engines down and raised the starboard up 1-2 bars to even out the gph. Trimming both up never helped with gph or speed on the 3 blades
 
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