19' Stealth

[Unchained]

I had a potentially bad situation on Saturday and this hull handled it great.
A guy with two 300 hp outboards was pulling alongside at about 35 mph.
I had to show him who was fast so I floored it and in about 4 seconds I looked down and the GPS was just over 100 mph.
Just at that time there were several rollers in front of me that were realistically 18" high and coming at different angles.
I thought "this could be bad"
I hit those things at over 100 and the hull handled it perfectly. The hull stayed level and didn't want to kite or pitch left or right. It felt like the cushion of air the hull rides on kept it from getting out of control.
The entire boat was out of the water and the pump was sucking air.
Waves of that height are higher than the sides of this boat.
My hat's off to Tom Papp Racing for a hull design that was real stable and safe at high speed in rough water that it was not made to operate in.
http://www.***boat.com/image_center/data/500/220unchatbrowerpark2-med.JPG
Mark

[Duke]

big thumbs up to tom papp and showing the outboards who the boss was!!!

[steelcomp]

Mark,
Are you still playing with the "duct?"
I did that once in my Bahner at around 90...thought it was history, but kept my foot in it thinking the worst thing I could do was lift. Came out on the other side thinking, "oops...I went pee pee!" :boxed:
steel

[MAXIMUS]

I had a potentially bad situation on Saturday and this hull handled it great.
A guy with two 300 hp outboards was pulling alongside at about 35 mph.
I had to show him who was fast so I floored it and in about 4 seconds I looked down and the GPS was just over 100 mph.
Just at that time there were several rollers in front of me that were realistically 18" high and coming at different angles.
I thought "this could be bad"
I hit those things at over 100 and the hull handled it perfectly. The hull stayed level and didn't want to kite or pitch left or right. It felt like the cushion of air the hull rides on kept it from getting out of control.
The entire boat was out of the water and the pump was sucking air.
Waves of that height are higher than the sides of this boat.
My hat's off to Tom Papp Racing for a hull design that was real stable and safe at high speed in rough water that it was not made to operate in.
http://www.***boat.com/image_center/data/500/220unchatbrowerpark2-med.JPG
Mark
You were probably only running 45 or so! :rolleyes: :rolleyes: :D It does make certain parts pucker!!! How is that sled running?? :)

[Unchained]

Mark,
Are you still playing with the "duct?"
I've still have that duct on there and I considered that it may have played a part in the stability I had going over the rollers at high speed. I think the sides of the duct want to keep the boat going straight.
I tried removing the shoe and it didn't like that, lost 10 mph in 1/8 mile testing. Evidently the pump wants to be force fed.
Then I put the shoe back on with a 1/8" shim behind it and it liked that better. Now I'm over 100 mph in 1/8 mile and I think it wants more intake pressure. It's hard to watch all the gauges at high speed when the waters rough. I don't have a real good handle on the intake pressure reading.
My 1/8 mile amounts to stakes along the shore at the local river. Nothing real precise like timing lights.
I'll be taking a video soon here so I can see all the gauges during the run.

[Heatseeker]

Mark, glad you made it through the rollers!!!
I had a similar situation riding in my cuz's hydro. He was cruising about 80-85 and hit some rough stuff without lifting. I about messed myself and cuz was laughing his ass off at me, telling me "we're riding above most of those rollers". Yea yea, scary stuff anyway.
That boat of yours is a monster for sure!
Have fun and be safe!

[Larry Nebb]

I've ridden/driven alot of 19 - 21' tunnels and they all did good in wicked chop at speed. The wackers seemed to do the best as they seem to ride higher and stay hooked up longer when it gets real nasty. All that air packed under it sure makes for a soft re-entry for sure.

[sanger rat]

Dang! I really wanted to go and see that boat run. Already had plans to go to the Frankenmuth car show. http://www.***boat.com/image_center/data/500/1937picfrankenmuth3.jpg

[Cs19]

I've still have that duct on there and I considered that it may have played a part in the stability I had going over the rollers at high speed. I think the sides of the duct want to keep the boat going straight.
I tried removing the shoe and it didn't like that, lost 10 mph in 1/8 mile testing.
I'll be taking a video soon here so I can see all the gauges during the run.
Have any pics of this "duct" your trying out? I would love to see what your trying.
I know exactly what you mean about these boats running well over the chop,they are very forgiving, it may have been another story in another hull design.
Cant wait for the videos, I plan on taking some video of mine as well in the next couple weeks.

[Unchained]

Here's the pics of the duct.
http://www.***boat.com/image_center/data/500/220Duct1-med.jpg
http://www.***boat.com/image_center/data/500/220Duct3-med.jpg
I've cut the leading edge of it back twice so far.
I've been running it all season. I know it needs some flathead screws. I need to make a special tool that will get the countersink close to the side of the duct and cut stainless also.

[1978 Rogers]

Forgive me for the question. What does a duct do? I know it must help keep water loaded in the pump or something like that? I'm guessing here.

[revndave]

Whats that duct do?

[Cs19]

Now there's something you dont see everyday.
Do you think it works well Mark?

[396_WAYS_TO_SPIT]

Ok I am a little lost on the duct thing as well :confused: :confused: Does it help keep the pump loaed in chop???? :confused: :confused: Out of all the lake/race boats I have never seen a setup like that.
396

[Aluminum Squirt]

Hey Unchained, how bout you start a new thread with some pictures of that "duct", how it works, how you set it up etc, etc. I love different/new stuff. On the white water, we'd flaten that thing in about 3 seconds but it looks pretty cool and I'm intersted in how it works on a lake boat-Aluminum Squirt

[Unchained]

The object of trying that part was to give the hull lift and to contain the intake overpressure at high speed shutdown.
I feel it has done both of those things.
When I take my foot off the gas at high speed the back of the hull doesn't want to lift up like my Cheyenne did when I had a lot of shoe in it which was dangerous.
Also it appears to keep the hull running real straight going high speed and appears to keep the pump loaded in the chop better.
As far as testing with and without the duct I have not done that so I don't have the specific data that really means something.
I could use some help in that department.
It takes about 1/2 hour to remove so its not a real quick thing to put on and off. It bolts on with the intake bolts that go through the bottom of the hull.
I drilled out the front two bolts to 5/16" and use allen bolts.
As long as I feel its adding more than it's subtracting I'll continue to run it while I'm fine tuning the rest of the pump setup.

[PC Rat]

Is the horizontal portion of the duct parallel with the keel line or have you put some angle in it?

[Unchained]

I've got it parrallel with the keel now so if the hull has a 5 degree up angle while running then thats the angle the bottom of the duct hits the water at.
Things I considered experimenting with are,
Making a new duct where I could adjust the angle easily to try different angles during the same test day at the river.
Extending the back of the duct behind the transom for more running surface.
Adding way more shoe and see how much I can overcharge the pump and get any possible gains.
This may take another year to figure out.