Saber 101
#131
Charter Member #232
Charter Member
Slipping when? When you are getting on plane? When you are running at speed? Just because a 4 blade is slipping don't mean jack chit! Try different props. I know it is a PITA but just try stuff. You are in uncharted waters so you have no idea what is going to work best and the prop that will likely work best with this set up is what you think won't.
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#132
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I agree, try everything prop wise that you can lay hands on. Dont count anything out. I have always wondered about CG on these hulls, may have a big role to play in how they ride. Mine will only porpise under 50, and then only if I trim out, rides perfect trimmed in. Once I get over 50 and trim out a bit, that is when the hull really shows its stuff. This hull works at speed, there have been a couple that ran over 100 at one time so you should be good once its figured out.
#133
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Slipping when? When you are getting on plane? When you are running at speed? Just because a 4 blade is slipping don't mean jack chit! Try different props. I know it is a PITA but just try stuff. You are in uncharted waters so you have no idea what is going to work best and the prop that will likely work best with this set up is what you think won't.
#134
Charter Member #232
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Have you been filling up the tank every time you go out? I am wondering if the bounce is getting better as you empty the tank?
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#135
coolrunning racing
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The fuel load should not have a large effect on CG if the boat is set up correctly. It should just make it lighter as it empties. Other wise it is a problem that needs fixing!
#136
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I looked at my Donzi with a TRS on it and it trims down about the same as what I am looking at with Arti's picture. Arts picture looks a little bit like the bow may be down a bit? At any rate you are not going to run at speed with it unless it is trimmed up so IMO this is a non issue because you would run nutral or possitive trim at speed. Both my Donzi and Formula have rocker. My buddies Formula (same exact boat as mine) is a porpoising mess were mine is not. 311's have rocker in them as do 302's as well as Donzi's. IMO there is a HUGE CG issue with these things. I don't think it is the drive, they are porpoising messes with Bravo's so.... Got to get to the bottom of the issue. IMO you will find to much weight up high and to far to the back of the boat. So the question becomes bandaid fix it by adding longer tabs, or some other fix like bags in the bow, or get to the bottom of the issue and start to look at the CG's.
At first thought. I agree one would think you are not in the usable range of the trim. However curing a boat that porpoises certainly requires a trim in. How can you trim it in if your already trimmed in. In other words "set the Hull" then come back and trim up.
The CG issue I crawled up in the forward bow way up and
added 180lbs to the nose. Equivalent to 4 sand bags?
According to captain Art it had now effect. By the way I was
Scared Sh@t have you ever gone for a ride with Art in a car
never mind a boat Anyway maybe two guys preferably gay
should go in the nose.
Right now that boat does not have the ability to carry the nose.
#137
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How do you know where the cg should be?
In setting up my cat I just called Peter at Skater and he told me
dead center of the fuel tanks.
I have a friend right around the corner with a crane who has offered
to help. I,m thinking 8 inch pipe "pendulum" gently lowering find the balance and theres ya CG.
#138
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we have a 13degree trans, with my box its 14 degrees. konrad doesn't think its the angle its drive height or too much weight out back. and I just spent 1400 plus on the new tank and thought about putting it in the floor with the weight out back. I just want to be able to control the porpoise at low speeds. I do need a run over 60 to see if it goes away. how is yours coming, if you didn't cut your x out I would set it at 16 1/2 = 4 1/2'' or 5'' with your its box. or wait and see where I end up. you don't have atrany and your drive is lighter than mine, b ut that konrad looks mean back thereart
I ofcourse built two 40 gal. saddle tanks that sit in my engine compartment, but will still have the ability to use my two 58 gal. tanks under the floor if need be and "center of gravity" is an infact issue..
However at the rate I'm going none of it's a real issue right now.. haha.. I wish I had some real world info for you, but since I don't I'll just say stick with it & keep good notes !!
The weather has been kinda nasty on & off here all week, but I plan on getting under mine over the weekend with a good straight edge & taking some good rocker measurements just to have, and would love to see a couple other guys do the same.. Not to derail the thread or get to much info going, but I would still like to know if all the bottoms from 87-97 are the same, or if the twin's & the single's were the same, also did anything change on the bottoms from boat #1 to #22 ect..ect.. ???? I know (weiland's) boat hull #1 was built originally with an arneson then later converted & your boat would have been the first "bravo boat" out of the mold, so just courious as to whether there was any bottom tweaking that went on back in them days... ???
Lastly I know my boat had to be the most azz heavy 28 they built considering it was a twin bbc boat with speedy #5's hanging off the back, and ofcourse tranny's inside.. I obviously have no idea how the boat handled at low speeds, and from what I know I'm not so sure anybody knew of it ever running "say" 30-60mph.. I still have the velcro wrist strap that was attached to the throttles, and I'm guessing again but I don't think JD had it in there for cruising..
Anyway's keep after it dude !!!
Last edited by littledcsrodshop; 10-21-2011 at 02:42 PM.
#139
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