Hi 5 prop...likely results

QBhoy

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Guys
Posted earlier in prop section, not remembering about this section. Posted the following. Any likeminded kin or thoughts welcome....


#1
Speed loss expected when going from 3 to 5 blade
Today, 05:05 PM
Guys,

Would like to think I'm pretty well up on propeller dynamics and issues 30+ years experience with fast boats (or as much as one can be on the black art or prop selection, haha) and I'm terribly aware that all boats respond different to different props, even unexpectedly ! So I ask the following question in the hope that people who have done the proposed can give me their experiences with similar set ups and circumstance. Even if you haven't, I would like to hear opinions and educated guesses from forum.

I can't complain with my current set up, having the slip rate as about as low as it gets, but I'm wanting to get back into a bit of watersports this year and would like a prop that isn't too much of a compromise when not wakeboarding and water skiing.
The obvious candidate is a Hi 5 prop. So the question is how much top end will I loose when going from the tried and tested laser 2 to this ? Will it be minimum enough to be able to leave it on all season.
All the above is asked when keeping the same pitch of 19".
Thanks.
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rallyart

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The High 5 is not as efficient, and you'll lose a some MPH, maybe six. You might be better with a vented 4 blade to give you more slip coming out of the hole and at slow speeds. This would allow you to regulate how quickly you get on plane by letting the engine RPM rise sooner with the added slow speed prop slip they can
induce. You want the push of a larger surface area prop but that can cause the engine to bog more while the RPM is below your torque peak.

One useful characteristic of watersports props is to run the engine at higher RPM at lower speeds so that speed control is more consistent. Many watersports occur near planing speeds so finer engine control is useful. This is the part that will hurt your top speed the most, as it usually means a lower prop pitch.
 

QBhoy

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Thanks rallyart.
A great point about the speed control. The laser 2 will sit at a min of 20 mph at best on plane. Even then it's not happy.
 

floater212

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try a Ron Hill pleasure 5 blade, the wider width and bigger diameter makes a world of difference. the high five is 13 3/8" while the pleasure is 14 1/2" diameter, pushes more water and the blade width is wider, more grip in water too. and at just about half the price of a high five. I got 1 3yrs. ago and been happy with any skiing, tubing, wake and knee boarding with a full boat, I couldn't be happier. IMO.
 

QBhoy

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Thanks Floater. I'll have a look at them now. Never heard of them.
 

SRTroop

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I had problems with my 5.0 MPI on a Sea Ray 205 Sport and turned out it was severely under propped with a 21P Vengeance. It only delivered 4100 rpm WOT with a 6-8 second hole shot. Found a used 17P Hi Five (wanted a 19P) and it gave me a three second hole shot and I had to back it off before hitting the upper 4000’s. The prop gets skiers up fast and holds speed. Just need to back off and be careful to never run full throttle. Acceleration and grip are insane. Highly recommend if you are in this situation.
 

flyingscott

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It is one of the better holeshot props for watersports. Another thing they like to is to run deep n the water. I ran one one my starcraft tournament pro 18' fibergalass boat with a 175 efi merc on it. The motor ran so much smoother and handled better in big water with the high 5 prop.
 

QBhoy

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It is one of the better holeshot props for watersports. Another thing they like to is to run deep n the water. I ran one one my starcraft tournament pro 18' fibergalass boat with a 175 efi merc on it. The motor ran so much smoother and handled better in big water with the high 5 prop.

Totally agree flying Scott. They are defo great for towing and grip for sure. But you need to be totally using the boat mainly for towing for them to outweigh their downside characteristics. Poor efficiency, economy, cruising and top end ability...compared to a 3 blade
 

QBhoy

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Jeez this is an old post of mine haha. Think I wanna asking this when I was trying to add to the prop collection not long after getting my current boat. Had a high 5 on a larger boat previously but had no reference of rpm or gps from that boat years ago.
If anyone is interested...I did try a high 5 on the boat. Was a 21”. Was as good as a 19” 3 blade at hole shot, but very poor too end and cruising. Also hit the limiter very easily. Looked good though haha.
 
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