28 pitch thru 32 pitch, same speed

[cfm]

Put stock power in it, sell it, and get a boat that would appreciate that motor more ?
Something to think about.
Raising the drive enough and doing some bottom work may not give you what you are looking for. It may....but this will be a road never travelled unless you find someone with the same exact boat that has done this before.
But, some people like to go down untraveled roads and enjoy the challenge even if the ultimate result ends up be nothing.
Depends on you.

[ghittner]

Put stock power in it, sell it, and get a boat that would appreciate that motor more ?
Something to think about.
Raising the drive enough and doing some bottom work may not give you what you are looking for. It may....but this will be a road never travelled unless you find someone with the same exact boat that has done this before.
But, some people like to go down untraveled roads and enjoy the challenge even if the ultimate result ends up be nothing.
Depends on you.
You are correct in what you say. I've built the motor for my "next hull" and the fact that it is in this one is only due to it's the boat I've had for 12 years. I'm looking forward to a 29 Ft or so next and am just starting to look @ hulls to transfer this motor into. But for now, it's what I'm running and I'm wondering what can be done for top speed. I am not willing to do ANY hull work on this boat. Again what should I be looking for regarding drive height? And yes, I own the fastest Arriva ever built and I'm sure of that. HAHAHAHA!!!!

[ghittner]

I always felt as though it had a parking brake on when I gave up the throttle. I have to trim this boat so far up it's unbeleivable. What would be the best overall depth considering stability as well as speed? At what point do you give up the excellent handling characteristics of this boat? I will post pics for you all to look @ later today, please all of you, take a look. Thanks
Darrell, I appreciate the offer as I've never pulled a lower and have only pulled the entire drive too many times too count.....
In general, what speed increase can one expect from increasing drive height each inch? Say maybe from 10" to 7" or 6"? And what would the optimal drive height be?

[BDMar]

Here You Go, The Hull!!!!
In your first picture the drive is not parallel with the keel. That will give you a lower x-dim measurement. It is critical to be correct in all your measurements.
If it is 9" below the keel a 3" shorty wont help you a lot. Single vee's do not like the Imco style lower with the crescent above the bullet. Especially heavier ones like yours. Your boat requires a lot of trim even if the x was higher. When you do that the front of the bullet acts like an anchor and creates a ton of drag.
Not spamming, but we modify the nose on Imco's all the time to correct that problem.

[ghittner]

In your first picture the drive is not parallel with the keel. That will give you a lower x-dim measurement. It is critical to be correct in all your measurements.
If it is 9" below the keel a 3" shorty wont help you a lot. Single vee's do not like the Imco style lower with the crescent above the bullet. Especially heavier ones like yours. Your boat requires a lot of trim even if the x was higher. When you do that the front of the bullet acts like an anchor and creates a ton of drag.
Not spamming, but we modify the nose on Imco's all the time to correct that problem.
What do you find the effect to be when installing the nose cones? I've heard good and bad on that. What about a nose cone on the standard Bravo? Any help on my application?

[ghittner]

In general, what speed increase can one expect from increasing drive height each inch? Say maybe from 10" to 7" or 6"? And what would the optimal drive height be?
xx

[cfm]

Here you go !
IMHO, this is a great price and a fast hull.
http://www.speedwake.com/upload/show...0&pagenumber=3

[cfm]

OOps. Double posted. Doh.

[BDMar]

What do you find the effect to be when installing the nose cones? I've heard good and bad on that. What about a nose cone on the standard Bravo? Any help on my application?
It's not a nose cone, rather a complete modification to the gear housing. On a 25 Daytona OPEN BOW (I know it's a cat) with a 540 normally aspirated BBC, we picked up 9 to 10 mph. The drive is mounted lower on an open bow because it needs more trim.
On a 24 vee we picked up 8 mph.
The key is that the gain is larger the deeper the drive. This is strictly on an Imco (Speedmaster style) drive.
Installing a nose cone an a standard Bravo helps feed the prop and will increase speed slightly. There are many variables as to how much you will gain. The earlier Bravo gear cases (88 & 89)respond better than the newer ones. Drive height, hull design, horsepower, etrc. are all factors. There also different nose cone manufacturers and some are bettrer than others.

[MACHINEHEAD]

Did your boat have an alpha at one time? That hull has many lifting strakes at the bow, seems like it would have some good lift if they ran most of the way back. Just for grins try a merc. revolution4 . Last I heard they only go up to 27" though. But it might steer you in the right direction. The imco style lower wont work on a non trim sesitive v-hull. Further, a 3" shorter anything probably wont do much. If you were going to move the drive up, I would go all the way to the top of the transom relief 5-6" up maybe.