audacity

tabs, for the most part are a band-aid...you need to look at the bottom of the boat first and foremost...and why are we even talking about spacers when you never stated what your x-dim. is?...OR did i miss it?

throttleup

Joey,
How are you? Welcome back to the States.
Just looking at different options, that's how the spacer issue came up.

I agree with you about the tabs, just a band aid. The same is the case with props. If you have to tweak a prop to an extreme to get a boat to run right it's just a band aid and not really fixing the problem.

Matt

audacity

yeah matt...i like this country...

HPJunkie

Audacity,
no you didnt miss it. I do not know how to accuratly measure it. Is the x dimension measured with a 90 deg square put to the bottom of the boat and measured up to the bottom of the drive gimble at the transom? is there a photo I can see or sketch that would tell? I do not think I need tabs as the problem is lack of bow lift... not rough water handling or too much bow lift. The prop shaft is approximatley 3" below the bottom of the boat

Matt,
It just goes slower as I trim and a rooster tail forms out back.

The boat is a pad bottom boat (about 10' wide) and I think it should run with more of a Hydrostream/Allison type of "set" or "attitude" rather than bouncing like it does.
Greg

zt260

Since the propshaft is only 3" below the hull and your slip is 12% with a bravo one, your boat hooks up very well. Cheapest thing to try would be a 1" spacer and the mirage 29. If it works well, lab it. Or if you can try a 5 blade with your present setup it could settle the boat. All it takes is time and money, I prefer to get the most for my dollar.

On another note, 25' hulls running near 100mph need a lot of help to work well. I agree you should be able to run WOT without tabs, but you may have to blueprint the bottom. My hull is 1' longer and it has taken me two years and a lot of money to get it dialed in to run 100+ reliably.

Good tabs improve the ride quality in rough water. I can’t spend most of my time at WOT, so ride quality while cruising at 50-75 is a priority.

audacity

x-dim=propshaft centerline to the the bottom of the hull directly in front of the propshaft centerline...both parallel...

1st you need to look at the bottom of the hull. FIRST! everything else is a distant second. NOT saying you need to blueprint(you may) the hull, it just needs to be assessed.

"All it takes is time and money"....no, it's all about knowledge...there are plenty of big dollar teams and manufactures bring up the rear!

at first, people think i charge a lot to do what i do(there are others too)...but, in the long run, you will have a better, faster product in a very short amount of time...with the fewest parts sitting around collecting dust.

ps...do you have external steering?

audacity

one more thing:

"it's not how fast you go, it's how well you go fast"

i read that in powerboat once

boatn70

Im on a different computer now Im boatn70, THis Is HPjunkie here.

ZT, your first plan Is my thought. The running surfaces are straight and sharp enough to take the skin off of your knuckles including the transom. Now I haven't equalized the widths of each strake just taken out the unlevelness of each and sharpened the edges of the strakes, chines,steps and the transom.

audacity ,

I do have Imco dual ram full hyd. helm steering. it seems like it hits the first step then bounces up. It does this on smooth water as well. it seems like too much trim but that is not the case. Have you ever added a spacer and improved performance?

Greg

zt260

If the bottom is true then a spacer would be my next step. I have personally seen spacers help performance. I would estimate your X dim is at 15" give or take (high) It’s likely a spacer will help and it's reasonably inexpensive for this sport.

Knowledge will reduce your costs, but you still have to buy the parts you need. Unless your sponsor is footing the bill.