Got a 2:1 gearbox in your G? I did some prop testing on an alternative....

[Wayward]

Ever since I got my 2016 G23, I was a little annoyed by a top speed of 37mph, and higher revs when surfing, boarding, and cruising. I hardly ever go over 25-30 mph when cruising, so, I don't need the speed. But I am sick of listening to the engine scream, just to cruise up to a restaurant or over to a friends house.......Up to this point, there wasn't much for 17" prop options. However, ACME is finally making one that I like a whole lot better than the 17x17 2561. I know that equal pitch and diameter gives you the most efficiency in a prop, which makes the 2561 an excellent choice, but I really like this new 3047 17x19.5. I have about 20 hours on it now, and a bit of data. I won't be switching back to the 17x17, unless I damage this 3047, and need a weekend saver.

I have the XR 7 550, so I have no issues turning this prop. That said, after collecting the data, and seeing the difference, I am guessing this prop would still be great with a heavily ballasted H6 setup. The H5 might not have quite enough juice, if the boat was really freighted.

Here is what I have-
ACME 2561 stock prop
Top Speed- 37.8
Time 0-37 mph empty- 11.4 seconds
Time 0-23 mph full stock ballast- 7.6 seconds
Time 0-23 mph full stock + 2 1100lb fat sacks side by side on lounge area floor, and 600lbs of lead spread out through boat("freighted" in future data)- 12.25 seconds
RPM at 23 mph stock ballast- 3800
RPM at 23 mph Freighted- 3900
RPM surfing on stock ballast at 11.6 mph- 3300
RPM surfing freighted at 11.6- 3450

ACME 3047
Top Speed- 42.4 mph
Time 0-42 mph empty- 11.2 seconds
Time 0-23 mph full stock ballast- 7.85 seconds
Time 0-23 mph freighted- 13.1 seconds
RPM at 23 mph stock ballast- 3550
RPM at 23 freighted- 3600-3650 (kept jumping that increment)
RPM surfing on stock ballast at 11.6 mph- 2900
RPM surfing freighted at 11.6- 3100

As for fuel usage, take it with a grain of salt, because it is not long term data. Being early season, there is no cruising, or idling in this. We back out, we load up, we ride. Just surfing this time of year. It is good for logging GPH when we are only doing one thing with the boat. However, it's just not much long term to give a concrete average.....

Both of these were taken on back to back sunny days that we had this last weekend, and only running stock ballast. The data from above was done by myself and my neighbor on a sunny day that we had nothing better to do..... it's funny what you will do to fill the day at the lake when it is early season in New England!!

ACME 2561- 7.2 GPH (filled boat full, went out with 6 other peeps, and rotated out about 4 hours worth of towing. Filled boat back up after and counted)
ACME 3047- 5.8 GPH (same routine as above, except we had 8 of us, and surfed a little longer)


pretty big big difference in GPH, but there is a pretty big difference in surf RPM, so I wasn't terribly surprised. That said, I won't be shouting this from the rooftops, as it is a limited dataset.

nonetheless, I would recommend this prop to anyone with an H6, that is at, or near sea level. And would probably recommend to all with an XR7. The increased pitch isn't noticeable on acceleration, even when heavily loaded........ and the lower RPMs while surfing, and boarding, is nice for the ears, and nice for the fuel tank. A difference of 400ish RPMs while surfing doesn't seem like a huge difference, but it is amazing how much quieter the boat is, when it is running at 3000rpms or less.

[markj]

I'm in the market for a spare prop and we surf 95% of the time. You've got me thinking differently about which way to go now. I would appreciate a drop in RPM's and fuel savings for sure.

[JoeA]

With the 2:1 tranny I could definitely see this alternative prop being an excellent choice. Keep us posted if you still like this setup as you get more hours on the boat.

[Kmayotte]

I would love to quiet the boat down. I was surprised at the decibel level of the engine when underway. Not a lot of forum user seems to share this opinion though.

[Bevostein]

Interesting. Basically a 10% decrease in RPM with very little loss in acceleration

[Wayward]

JoeA- will try to include future thoughts in this thread. So far, I'm loving it, but it is definitely early for a final verdict.

[SierraWave]

Thanks! I have been thinking about which one to go with and didn't know acme had added this prop but it is definitely the direction I was headed. Where did you buy it?


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[Wayward]

Sierra- Ordered it through my dealer.

[OKWAKEBDR]

Would really like some real world experience on how it performs in the 450.

[JoeA]

I feel like my 2015 G23 550 is pretty quiet although I do not have the 2:1 transmission. Is the consensus that the 2:1 tranny creates more noise or just more RPS = more noise?

[Wayward]

^ I think just because of the higher RPMs.

When it comes down to it, the 17x17 and 2:1 is an excellent combo for getting the base engine to perform well with extra ballast and a full boat..... and that combo would easily do anything you ever wanted with the 450. On the 550 though, it is an extremely overkill setup. You just don't need that combo when you have that much power. Even with this 17x19.5, it still absolutely rips out of the hole when heavily loaded with over 5500lbs of ballast. After testing it out, and seeing the results, I almost wish it was a 17x22..... but that much differential between diameter and pitch might have efficiency issues.

I do think this prop would work well on the 450, even heavily loaded....... but definitely couldn't say for sure. It certainly doesn't hold the 550 back at all.

[Neverenough]

I would love to quiet the boat down. I was surprised at the decibel level of the engine when underway. Not a lot of forum user seems to share this opinion though.

First thing my wife said when we took our G out for the first time.... Now I notice it!!!! Its certainly louder than the old 343 and 1:48 230!! Once I get all ballast figured out I hope someone has tried this with the 450...Wayward thanks for taking the lead on this!

[bakerdr27]

A while back there was a long thread on either mastercraft or Malibu forensic that investigated props. It would appear that Eric Johnson at OJ Props 1 800 359 9730 was very intelligent and helpful in this regard. I'm looking forward to him providing an optimum prop for my GS20 with an H6 engine (I think the prop that it ships with is too small)


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[Wayward]

^ Eric at OJ is awesome. To be honest, I wish I could have done an OJ prop, because that company is so great to deal with. You can request them to cut anything you want for a custom prop, and you will see it within a week.

With all of that said....... I had Eric cut me a 17x19 for my 2016 G23 last year. For some odd reason, it made the surf waves dirtier, especially the starboard wave. It washed it out terribly, and I have no idea why. I talked with Eric, and he did say that can sometimes happen with certain hull and prop combos, and the blade design might not be a good choice with the G hull. I actually swapped it on and off twice, because I thought something else might be wrong. That wasn't the case, though. Something with the prop was washing the wave, so I sent it back. Others results might vary. Idk

[LakePowellMan]

Wayward--awesome data. I've been hoping someone would do some testing for a different sized prop. Thank you!! I've needed a "weekend saver" and this may be the way to go for my primary prop, and keeping my stock prop as the back-up. Please keep us posted if you see any changes in the data as you spend more time with the prop. I have a 2016 G23 with the XR7 and boat primarily at 3,000 to 6,500 feet. What altitude were you for your test results? Thanks again!