Stability Curves

MV Off-Axis · #1 09-20-2010, 10:35 AM

I was wondering if anyone had the GZ curves for the V20. I just put a wake tower on my 1986 V20 since I do alot of wake boarding as well as Sailboat Regatta Management . I have not had her offshore yet since the tower went up but really have not noticed that much of a roll period change . The only thing I have noticed is she is a little heavier in the wind when on plane . Any Ideas ?

nipper · #2 09-20-2010, 02:49 PM

Sorry, I cannot help you because I do not know what stability curves or GZ curves are!

tsubaki · #3 09-20-2010, 02:56 PM

Think trim tabs would help to reduce the effects of what you are experiencing?

garagenc · #4 09-20-2010, 08:46 PM

Not knowing how tall your tower is and the weight of it makes it a little hard to come up with a exact weight of ballast. But I did one for a friend when he put a tower on his and what we came up with was: you would need to add approx 30lbs on each side as far fwd as you can get the weight before the hull shapes inward toward the bow. (The fwd end of the inserted rod storage in the gunnel. ) This helps to provide stability so the tower can't overpower the flat stability.

Hope this helps.

MV Off-Axis · #5 09-20-2010, 09:07 PM

Quote:

Originally Posted by garagenc

Not knowing how tall your tower is and the weight of it makes it a little hard to come up with a exact weight of ballast. But I did one for a friend when he put a tower on his and what we came up with was: you would need to add approx 30lbs on each side as far fwd as you can get the weight before the hull shapes inward toward the bow. (The fwd end of the inserted rod storage in the gunnel. ) This helps to provide stability so the tower can't overpower the flat stability.

Hope this helps.

Thank you ! the tower is about 70 lbs and stands 4 feet above the rail . She is a good wakeboard boat when she has full ballast tanks ( 1200LBS +-) but i dont run with them full unless i have some one on the tower. I Also have 2 wake speakers on the tower as well but they weigh nothing (8 lbs for the pair). I will try to find 60lbs of lead soon before i have to get her ready for Key West Race week in Late January

garagenc · #6 09-20-2010, 10:15 PM

To make it easier to adjust the weight you might try adding sand bags. Easier to set and they will mold to the structure and not make noise or be a hard spot for the hull during rough water. After looking at your pic I would suggest adding them to the area directly under your towers aft support leg. Same place I had described in the earler post.

With the sand bags you can add or reduce the weight as needed to get the least amount of weight to accomplish your goal.

P/s Most boats list to one side normally beacuse of batteries and fuel etc, adding a sand bag as ballast to the other side can level the boat out and help it run smoother in the water if you don't have trim tabs.

You may find out the 30lb each side I suggested may not be enough but may also be too much so you'll have to play with that weight. This is because without past history on how your boat rode and sat in the water this is a starting weight.

When you come up with the correct weight you may have to add weight to the bow area centerline to help plane the boat.

MV Off-Axis · #7 09-21-2010, 07:47 PM

ok cool , I will try the sand bags in that location . I will post up when i try it and let you know the outcome

nipper · #8 09-22-2010, 08:45 AM

I have often thought the V20 would make a good wake boarding boat. I would just love to see some pix or video of you pulling a wakeboarder!

MV Off-Axis · #9 09-22-2010, 07:11 PM

Quote:

Originally Posted by nipper

I have often thought the V20 would make a good wake boarding boat. I would just love to see some pix or video of you pulling a wakeboarder!

The wake is very weird on this hull , its small even with Ballast tanks full. but has LOTS of power . I use a Slingshot Response 137 and I can do wake to wake and a pro friend of mine can do his major tricks but he just cant get alot of air . . With 1500 to 1800 LBS of ballast it only increases the wake size by inches , Maybe like 4 or 6 at the most and gives the 150 Bluewater Merc a workout getting out of the hole. but it serves the purpose very well for Regatta managment and wakeboarding.. I will try to get some Video uyp on Utube when I get the camera tracker installed on the tower. But thats after I install wind Speed and Direction , and rewire the whole boat .

nipper · #10 09-23-2010, 12:39 PM

Can you describe for me exactly what you mean by regetta management? I think I know, but want to confirm. Thanks.