New prop suggestions to increase overall performance?

[Lee J]

Re: New prop suggestions to increase overall performance?

Great! I just placed my order and should have it by Next Monday. I know I should keep my enthusiasm low because in a way, this is sort of a troubleshooting step, but I'm excited to see if there is any change.

 

[Lee J]

Re: New prop suggestions to increase overall performance?

Well Iboats shipped quicker than their first estimate and I received it Yesterday, working out perfectly so I got to use it this morning!

The results of the prop hswii suggested are interesting.

Original numbers with a 16p elephant ear prop:
Cruise: 27mph @ 3500rpm
WOT: 32.5mph @ 4150rpm (after hull cleaning)

New numbers with Solas Rubex 4blade 15p prop:
Cruise: 28mph @ 3400rpm
WOT: 36mph @ 4350rpm ! (might hit 4400 if I let it)

So the boat was definitely faster and unless it was placebo, I really think I noticed it being smoother. I did the prop slip calculator and it looks like I'm at 23% prop slip, which is still very high, but a huge improvement over the original 32% prop slip I was getting.

I'm wondering what the next step is here, since my max WOT should be 4200 I would think I would need more pitch? But if I add more pitch with these prop slip figures, will the slip just increase? Could that sand-like crud that I cleaned off the hull still be causing these since I was unable to get to the spots under the 4 bunks and a couple crossmember pieces of the trailer?

Overall, the prop was an improvement and worth the cash, I'm just trying to optimize everything. Thanks again hswii and QC!

 

[hwsiii]

Re: New prop suggestions to increase overall performance?

Lee, we still have a problem somewhere, a 15" pitch Solas 4 blade will NOT have a prop slip of 23% on a hull like yours, unless there is a big problem. Your prop slip should be somewhere between 10% and 12% for your boat.

You need to remove the rest of those particles on the bottom of the boat, you can probably only do that with the boat in the water and a brush. We did gain speed and lessen the prop slip, but not what we should have.

Then you need to check for excess water in the hull itself, open all inspection plates and look everywhere you can, especially anywhere the inside of the hull has foam in it.



H