400 with 1.76 transmission prop choices

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Originally Posted by repomannv

Some really good info in this thread. I knew nothing about boats, let alone props before purchasing my 2021 SA 450... I just looked and I'm running a 16 x 17 prop, which is what my dealer must have spec'ed for me. We only wakesurf, and with a lot of weight on the boat, we have struggled to get the boat to maintain autowake desired speed (say anything above 10.5mph), particularly on heavy current/wind days. I'm thinking now I should swap out my prop to a 16 x 13.9 given our use case.

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I would agree, i posted in the other thread with more detail but your issue is definitely your prop. Swapping to the 13.9 will solve it.
https://www.nettleprops.com/acme-359...e-105-cup.aspx

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Originally Posted by repomannv

Some really good info in this thread. I knew nothing about boats, let alone props before purchasing my 2021 SA 450... I just looked and I'm running a 16 x 17 prop, which is what my dealer must have spec'ed for me. We only wakesurf, and with a lot of weight on the boat, we have struggled to get the boat to maintain autowake desired speed (say anything above 10.5mph), particularly on heavy current/wind days. I'm thinking now I should swap out my prop to a 16 x 13.9 given our use case.

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Even a 16 x 15 will make a big difference. You would be surprised at how little bit of pitch change can go a long way on a boat prop. Just another fyi, which if you don't know anything about props at all, the first number is the overall diameter. The second number (pitch) represents how far the prop will travel through the water in one revolution. For example, your 16x17 is 16" across in size, and will move 17" forward when it make one revolution. NOW. Having said that. The 17" does not really take place because of slippage since water is not a solid object. There are a whole bunch of theory formulas with many variables to figure out what the slippage equates to. But just think about it like putting smaller or larger tires in your truck.

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Originally Posted by larry_arizona

My understanding is cupping reduces the diameter a smidge and is a secondary tuning feature to further optimize pitch.

https://uploads.tapatalk-cdn.com/202...8271b2d905.jpg


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Yes. This makes perfect since, and is what I was talking about with cupping adding surface area is diameter stayed exactly the same.

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Originally Posted by HFarr

Yes. This makes perfect since, and is what I was talking about with cupping adding surface area is diameter stayed exactly the same.

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"IF" diameter stayed exactly the same.

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ACME makes two 16 x 13.9 props, only difference appears to be cup:

#3557 which has a cup of .075"
#3591 which has a cup of .105"

The #3591 is backordered about 3 weeks right now, #3557 is available, question is, is it worth the wait for the 3591, would an operator notice the difference?

Quote:

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Originally Posted by repomannv

ACME makes two 16 x 13.9 props, only difference appears to be cup:

#3557 which has a cup of .075"
#3591 which has a cup of .105"

The #3591 is backordered about 3 weeks right now, #3557 is available, question is, is it worth the wait for the 3591, would an operator notice the difference?

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https://www.nettleprops.com/

https://www.deltaprop.com/

https://www.generalpropeller.com/acme-3591

All show in-stock. Never dealt with General Propeller but I have talked to the other 2 personally and both are willing to help you decide.

I know I keep saying it, but the 3591 was co- engineered by ACME and Supra for the 1.76 trans.

That said, not sure if you would notice the cupping difference.


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OJ props has a 16x14 that my buddy is using on his new SL, it is really nice.

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Originally Posted by Holdmybeer

https://www.nettleprops.com/

https://www.deltaprop.com/

https://www.generalpropeller.com/acme-3591

All show in-stock. Never dealt with General Propeller but I have talked to the other 2 personally and both are willing to help you decide.

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Nettles is out of stock, I called. I opted for the #3591 and the wait, should be interesting to see the difference, and now I'll have a backup prop as well :)

Is it possible to run the 16” prop on a 2021 moomba?