Pat McPherson

On my Velocity, the "full length pad" is a basically flat area on the bottom instead of the bottom coming to a V. It runs from stem to stern and is 12-14" wide.
My hull also has 4 full length strakes not counting the chines.
Most old school V bottoms have 2 full length and 2 that start at the bow and end 1/2 way back.
The hull also has a notch transom so the drive can be mounted higher and still get clean water to the prop.
The Velocity does have a 24° dead rise bottom, but rides up on the pad when going fast.
This is the first boat I've owned that is not an old school straight V. I went this direction so that I could have a bigger boat that would still run pretty fast with mild power.
Here is a running pic from the last owner.
Like I said earlier, I'm learning the boat and the jury is still out...

bcarpman

Yeah, that runs pretty high on the water. amazing with a full length pad it doesn't slam hard when the water gets rough.

Be interested to hear your thoughts once you get more time in it.

bcarpman

How is the degree of bow lift defined? In one of my boat books it's defined as the change in attitude from the way the boat sits off plane, but that doesn't make sense at all as my boat sits with the bow WAY up off plane.

I've had two people tell me two different things about the effect of prop depth on bow lift. One said a deeper prop will raise the bow and another said the oposite.

BenPerfected

I don't really know exactly how you measure the degrees of bow lift. I am thinking it may be as compared to the angle of the strakes...like on the trailer. Our pursuit of the ideal X was all trial and error. We started by raising the "X" 3" by raising the extension box 1" and adding a 2" shorty lower. We first tested with 3" spacers to confirm a base line and the efficiency of the Imco lowers vs the std Bravo lower. Next we changed to a 2" spacer, then 1" , and then no spacer. As the boat may handle differently at different X-dimensions, it is possible you could also have to adjust the bottom, strake length, etc to achieve the right balance and attitude. This process , including finding the right props added over 13+ MPH. This was the biggest Home Run we every had in 20 years of pursuit of more speed.

bcarpman

Just thought I'd post some details on just how bad my hull must be (I say "must be" because we can't think of anything else that could be at fault).

The boat came with a stock 330hp 454. I would run 53gps on a good day with a light load.

If you put 5400 lbs, 300pshp into:

http://www.go-fast.com/boat_speed_predictions.htm

and you get a hull constant of 223 which would seem about right for a conventional V of this vintage.

So then I drop a "330 on Roids" in that dynoed at 460hp and the boat barely hits 59or60 gps (Speed calculator says it should hit 63). Oil pump goes south on that engine after about 20 hours with the predicted consequenses. (still no idea what happened)

Drop a Tyler Crocket built 502 with 540hp and the boat still feels like it's bouncing off a wall at 60mph (speed calc says it should hit 69mph). The last 30% of throttle yields no speed increase.

No amount of drive trim will loosen up the bow.

Stock boat used a 21p 3 blade. Newest motor can't even turn a 24p 4 blade despite an extra 210hp. If I run a 25p 3 blade, it blows out before WOT.

I really do love this boat for everything other than top speed (It's a really spacious boat for it's size), and everyone commments on how nice it is both outside and in. So I'm not sure what I'd buy that would be as nice. Can't stand the baja's and you have to step up to a 30plus fountain/formula with twins to get a cabin/cockpit that's as roomy and as of now I can't afford that (business has been slow this year). Compromises!

Oh well, just rambling now.

MOBILEMERCMAN

Many boats like yours have wedges or hooks on outer chines to make the boat plane easily and cruise flat and nice. The things that make it cruise nice hurt at higher speeds. In addition to that the drive is probably buried in the basement. It is not as you have seen how much power you have; it is more how much drag you don't have. You can change the bottom ,add trim tabs, steering, Fill transom raise motor buy props and on and on.

Enjoy it for what it is. You can spend endless effort and money changing things and likely still be dissatisfied. If speed is important get a fast boat.

ZXXX Donzi

It takes a bunch of power to go fast in a straight V. I had a 27ZX (non-step) Donzi with a Procharger. It would break 70 on a good day. I figured that it would hit a wall in the mid to high 70's with bigger power. The ride and handling was unbelievable. The snottier the water the better. I played around with a Shorty and it did not like it. It takes lots of bow lift in a v. I probably gave up 3 mph due to running a 4 blade vs 3 blade with a conservative X but would have lost around 7 in cruise.

I wanted to go a bunch faster so I went with a step hull. And yes, it is much faster. I did sacrifice some ride and handling.


Enjoy the v-hull. I would have one again. Spend some time dialing it in and you may get a few more mph. I would not do anything permanent since not everything works with every hull. You don't see Magnums and V hull Cigs breaking speed records but they are still cool and have a great ride. The only way to really make them fast is to make them very light. If you want to do that then get a race boat.

Don't let the pad V guys confuse you. Those boats are a good bit different and can go fast. I have never driven one but have run with a few. I am pretty sure that they did not have they same ride I had as they bounced across the top of chop at 70.

bcarpman

yes, this hull does have built in wedges on the outside of the strakes. Another 257 owner said his are out of the water with enough power, but mine aren't. You'd think that would show in the slow speed hull constant, but I guess it's non-linear.

I already put homemade 20inch trim tabs on in place of the stock insta-trim and they do work very well so I'm sure I don't need the built it wedge.

So far I'm treating this boat as one big learning experience. I figure once I'm ready to move up to something really fast, I'll not only know what to buy and not buy, but I'll know how to drive a small boat fast in rough water (two weeks ago I was running 40mph in a 5ft random chop, something I would have never done just a year ago) which I would guess is a skill that will help me drive a faster bigger boat as well.

I've already put way too much money into the engine, and bought a well built drive to hold up to the power. Both bad investments in this boat in retrospect (Should have just built another "330 on roids"), I'm not going to put a bunch more money into the boat: paying someone to redo the hull, or a shorty drive, but I MAY experiment some this fall.

I've built many composite car parts including entire race cars out of fiberglass/kevlar/carbon fiber, so I know what I'm doing. If I really feel up for experimenting I may take off the wedge, blueprint the bottom, and raise the drive/engine.

I know, it's a lot of work for a boat that's never going to be particularly fast, but I figure I'd learn a lot from it and it'd be fun (yes, that's the kind of stuff that I enjoy).

Would be kind of fun to have a 70+mph 257 powerquest sleeper. I already get the weirdest looks as I idle around in what is obviously not a stock boat. Came out of the harbor last week just ahead of a guy in a VERY fast boat. Got on plane well ahead of him and it was funny how he made sure to pass me before he slowed down to cruising speed (slower than I was cruising). Not sure if it was the sound of my motor, how fast I got on plane and up to 50+ or the fact that it was him and his buddy, and I had four girls with me. I got a chuckle out of it though.

Pat McPherson

I know a fellow that took the hooks out of his late 80's 24' Formula and it made a big difference. That boat had a 330HP 7.4L Alpha. I think it went from a top speed of 52 to 57.
Then he bolted in/on a 575HP 540cube and Bravo drive. I think the boat then topped out around 70, maybe in the low 70s. He did not add external steering though and the boat became a real handfull.
Anyway, I think you will see a decent gain in top speed by taking those hooks out. You'll need to make sure your steering is tight and use the tabs.

Hydrocruiser

Actually a 17' Bayliner with a gorgeous woman is what makes the best hull!