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STV bottom design... 

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There are two current hull designs being built and marketed by our company TRIAD POWERBOATS. These are the original Roark Summerford designs and molds. The first one was built in early 1989, is now commonly refereed to as the "ski bottom". This was the first Roark Summerford "inverted V" design. The inverted V center pod is very pronounced, runs all the way to the nose of the boat and turns up very abruptly at the nose. The strakes on the sides of the center pad are angled downward on their outside edge. This bottom, according to Rusty Campbell, (who is a friend of mine and I see often) is capable of approximately 2 mph more speed on top end than the "MOD VP" bottom. The SKI bottom also will carry weight better because it has more lift designed into it.

    Remember that Roark was designing these hulls with one purpose in mind -- to win MOD VP races. The "SKI" bottom was quite capable of doing this, but it was difficult to "race turn" -- that is drop the boat, turn it, set it quickly, and get back in the throttle, go through the turn and back into the straightaway. This first inverted V center pod had a little to much lift to "race-turn" quickly. It "coasted" when you let off, (lift held it up too long), and the nose had too much surface planing area, so it wouldn't sink quick enough to set the boat, sometimes the nose would want to "skip out" making it difficult to turn quickly.

    The next generation bottom was built in 1990, and is a modified version of the first SKI Bottom. A brand new hull mold was made for this boat. Roark removed a lot of the nose surface planing area. When you look under the nose of a "MOD VP" hull, the inverted V is much less pronounced, its shallower and blends into the nose of the boat in a much smoother transition. Roark also put a small turning edge on the starboard side of the front of the center pod to help the nose track better in the turn. (boat turns better to left than right because of this change). He also removed some of the overall lift from the boat by removing a portion of the turn downed lifting strake next to the center pad. Only a few boats were made like this.  

     The next generation (or evolution) of the hull was what people refer to now as the " MOD VP Hull" . A new mold was not made, but these changes were made in the existing mold. This was done in 1990 or 1991, the only change was that the last 4 or 5 feet of the two lifting strakes next to the center- pad were flattened to 0 degrees. This also assisted the boat's turning capability in a RACE situation. The current "MOD VP" hull we now manufacture, is this version.  

     As far as which is better? -- You decide --"SKI" carries weight better, has a capable 2 mph top speed advantage, turns good (except in all out race situations). HOWEVER -- the "MOD VP" does drive a little "sweeter, slows down quicker when you let off, turns good to the right, turns exceptional to the left. Rusty (and others who have owned both) say that the "MOD VP" hull does drive a little nicer "set and feel" (especially on a lightweight boat). Most people who order the boat!

    From us, we specify the MOD VP hull-- probably because Rusty Campbell won so many races and so many World Championship titles with that hull....and because it is called the race hull...but we do have some people specify the "SKI" hull when they order also. Usually if they dont specify either, we build them the MOD VP hull.

 

Hope this information was helpful. WL.

An email from Wally Lamkin at triad boats, thank-you

___

Article supplied by:

Helmut

98 Euro STV 2.5 EFI

Long Island NY

Posted July 24, 2001

Updated Feb 17, 2002

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