My race-cruiser has a traditional 2 blade (nonfolding) prop. Just before launch I noticed many of those high tech folding type props eg.Gori on other boats. Anyways just how much do the improve the performance of my 36" in a possible race event, and are they really worth the money? Is one better than the other and which one offers the best value? Comments...
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Folding Prop + & -
I put a Martec Folding Prop on my 28.5 when it was launched new in 1986 as I expected to maximize the boat's speed potential. I also use a back stay adjuster, a boom vang, a Head Foil Luff System, a Mylar 155% Genoa, a Dacron / Mylar 135% for higer wind speed in addition to the 'stock 110 jib. I also take several days each spring to re do the hard vinyl racing paint and wet sand the entire bottom, keel and rudder. So, my point is; how serious are you about the speed potential of the boat? Are you doing all the other things to be competitive? In the moderate winds I presume in Toronto, the folding prop may not seem to make as much difference as it very obviously does in a light air race on the Chesapeake Bay. I'd say it's up to 1/2 knot diference over a fixed prop. However, in my opinion, the drag of a fixed two blade prop right in front of the rudder causes more turbulence at the rudder which you compensate for by another two or three degrees with the rudder, thus even more drag and you aren't pointing as well. The negative side of a folding prop is that it takes centrifugal force to pop it open. It's a lot easier to engage the prop and have it open when you switch from sailing to motoring if you come head to wind and slow to below 3 knots. Backing and stopping with a folder just take some practice and using enough rev's. Another point; your handicap PHRF number assumes good sails and a good bottom but may give a typical 6 seconds per mile credit for the fixed prop. I personally think the folder is worth more than six seconds per mile, others may not agree.
I put a Martec Folding Prop on my 28.5 when it was launched new in 1986 as I expected to maximize the boat's speed potential. I also use a back stay adjuster, a boom vang, a Head Foil Luff System, a Mylar 155% Genoa, a Dacron / Mylar 135% for higer wind speed in addition to the 'stock 110 jib. I also take several days each spring to re do the hard vinyl racing paint and wet sand the entire bottom, keel and rudder. So, my point is; how serious are you about the speed potential of the boat? Are you doing all the other things to be competitive? In the moderate winds I presume in Toronto, the folding prop may not seem to make as much difference as it very obviously does in a light air race on the Chesapeake Bay. I'd say it's up to 1/2 knot diference over a fixed prop. However, in my opinion, the drag of a fixed two blade prop right in front of the rudder causes more turbulence at the rudder which you compensate for by another two or three degrees with the rudder, thus even more drag and you aren't pointing as well. The negative side of a folding prop is that it takes centrifugal force to pop it open. It's a lot easier to engage the prop and have it open when you switch from sailing to motoring if you come head to wind and slow to below 3 knots. Backing and stopping with a folder just take some practice and using enough rev's. Another point; your handicap PHRF number assumes good sails and a good bottom but may give a typical 6 seconds per mile credit for the fixed prop. I personally think the folder is worth more than six seconds per mile, others may not agree.
Like me
Seems more like a minute a mile. My buddy and I raced his boat with his two blade fixed. He thought, 'no big deal, they give you time'. Yea but, the time given is the same as no flying sail or no genny. That prop he was dragging was as if we were towing a bucket, FOR THE WHOLE RACE. We went from the middle of the pack to watching them sail over the horizon, in front of us. He bought a max prop. I have one too. If you want to enjoy the fruits of sailing IE; going as fast as you can, then you have no choice.
Seems more like a minute a mile. My buddy and I raced his boat with his two blade fixed. He thought, 'no big deal, they give you time'. Yea but, the time given is the same as no flying sail or no genny. That prop he was dragging was as if we were towing a bucket, FOR THE WHOLE RACE. We went from the middle of the pack to watching them sail over the horizon, in front of us. He bought a max prop. I have one too. If you want to enjoy the fruits of sailing IE; going as fast as you can, then you have no choice.
Also Better VMG with Low-Drag Prop
Not only will a low-drag prop make your boat go faster but the VMG is also better because there is less side-slip. We aren't talking "pointing" here, the boat will point the same as before, we're talking "tracking". Sail behind a boat with a fixed-blade prop and you can see them actually drift sideways which is costing distance to weather. The more drag (fixed 3-blade vs fixed 2-blade) the more distance lost. With a low-drag prop the side-slipping is really reduced. Low-drag prop = (Faster boatspeed) + (Better tracking angle) = a heck of a lot more fun! On our Hunter 35 the increase in boat speed with a Max-Prop is around 0.4 to 0.5 knots. Stated in other words, it's like flying a 150 vs a 110 or a standard spinnaker vs a 150. Usability: the low-drag prop can be used going upwind AND downwind, or 100% of the time you're sailing.
Not only will a low-drag prop make your boat go faster but the VMG is also better because there is less side-slip. We aren't talking "pointing" here, the boat will point the same as before, we're talking "tracking". Sail behind a boat with a fixed-blade prop and you can see them actually drift sideways which is costing distance to weather. The more drag (fixed 3-blade vs fixed 2-blade) the more distance lost. With a low-drag prop the side-slipping is really reduced. Low-drag prop = (Faster boatspeed) + (Better tracking angle) = a heck of a lot more fun! On our Hunter 35 the increase in boat speed with a Max-Prop is around 0.4 to 0.5 knots. Stated in other words, it's like flying a 150 vs a 110 or a standard spinnaker vs a 150. Usability: the low-drag prop can be used going upwind AND downwind, or 100% of the time you're sailing.
Just Put One On
...a Martec S/S geared folder. Seems to make a big difference in light air and pointing, but I did other things at the same time so I don't have a base line. Just seemed wasteful to drag a prop around. BTW, backs just fine. Rick D.
...a Martec S/S geared folder. Seems to make a big difference in light air and pointing, but I did other things at the same time so I don't have a base line. Just seemed wasteful to drag a prop around. BTW, backs just fine. Rick D.
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