Building a "Turbo" Thunderbird

Discussion in 'Sailboats' started by FormulaReed, Jan 25, 2009.

  1. FormulaReed
    Joined: Jan 2009
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    Location: seattle

    FormulaReed Junior Member

    Hi,

    I am thinking about doing some mods to a Thunderbird to make a short handed and PHRF racer.

    Hear is what I am thinking about doing. I want to rig an asymmetrical spinnaker, either one from a Melges 24 or a J80 with a bow sprit. I would also like to open the transom.

    What do you all think? Do you think that the boat would sail to it's PHRF rating? Is this a really bad idea? I am concerned that the mast is not strong enough to hold the mast head kite in more than 12 knots. In the pictures that I have seen there is some seirous head stay sag in 10 knots or so. Is there any way that I can strengthen the mast?

    Thanks,

    Reed
     
  2. Paul Scott
    Joined: Sep 2004
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    Location: Spokane, Wa

    Paul Scott Senior Member

    Why go masthead? How about the jib hounds, with a couple of running backs? Lower aspect is better, deeper downwind, no? Easier to keep lit (and keep light), light airs or heavy, which has to be faster than the usual shorthanded drama, and easier to control in general. SLR's vs wind angle of Tbird vs M24 & J80 at different windspeeds have to be different, I'd think....

    What would an open transom do to the structure?

    Paul
     
  3. FormulaReed
    Joined: Jan 2009
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    FormulaReed Junior Member

    I have not been giving much thought to going with a fractional spinnaker. I wanted to go with a mast head to give the boat more sail area down wind. Do you think that I would see much performance gain with a fractional asymm? I have not seen a racing boat that has a fractional asymm, do you know of one that does and has a similar hoist (I think that a thunderbird is 26.75)?

    I was hoping to do two things by opening up the transom. I really don't like dealing with the outboard well and I was going to use a bracket for the outboard. The other would be to make the boat a little lighter.

    I am going to try to attach a pic of the boat that has inspired this idea... I hope it works.

    Thanks for the reply,

    Reed
     

    Attached Files:

  4. Paul Scott
    Joined: Sep 2004
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    Location: Spokane, Wa

    Paul Scott Senior Member

    I didn't realize that you were looking for more sail area.

    Wouldn't a symmetrical spin set from the mast head give you better performance? It would be more sail area, and a symmetrical can sail angles in the light stuff. I tried to find the polars on TBirds, but so far, no luck. But given what I think they are, how much do you think you'd be in a hot angle/powered up (aka assym) mode?

    Paul
     
  5. FormulaReed
    Joined: Jan 2009
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    FormulaReed Junior Member

    I want to go with the asymm for easier sail handling, I think that it would be much better short handed sailing. I also some times take out green sailors for beer can racing and getting someone to do bow can be hard.

    Other than the mast coming down, I am worried about the boat sailing to it's rating with a mast head kite (either asymm or symm). I think that thunderbirds are a little underpowered down wind. I can keep up or beat a moore 24, j24 or even a S2 7.9 up wind but once we round the mark I get smoked. If it's blowing over 12 knots I do a little better.


    I can't find the polars for my boat but I would bet that as along as your not running DDW or close to it an asymm would be faster. Even if your not quiet as fast, one bad jibe or set would offset any performance gain.

    Reed
     
  6. limeyus
    Joined: Apr 2008
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    limeyus Junior Member


  7. FormulaReed
    Joined: Jan 2009
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    FormulaReed Junior Member

    Ya, Foul Play is the boat in the picture that I posted. I wish that it was not on the other side of the country from me. I would love to take a look at it.
     
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