MY NEW SPORT 20 BUILD ...LEGAL OR NOT THAT IS THE QUESTION

[Mark Bullard]

If I understand this correct if he would fill in this erea he would be OK. Am I correct?
Bob

Sorry, that does not fix it.

 

[Bill Gibson]

Well I've been following this topic and thought I would add something since my boat would be considered illegal under what is being talked about on here. I'll attach some pictures of my boat. It has held the IMPBA oval record going on 9 years now. It is a WOF build and has a lot of similarities to Brad's boat (which I would consider legal). The bottom of the boat has unique design features, but I tried to keep the top deck flowing into the sponsons so that it would keep the sport look on top. I played around with filled in riggers prior to this boat and came up with this because I thought it was about as far as I could go without causing to much controversy. The way the IMPBA rules are written, I could have done more to the design, but decided not to.
It is sort of funny that 9 years ago I went through a lot of controversy on legality of the boat and no one could prove that it was illegal under the IMPBA rules. It was different than what everyone is used to seeing, but not illegal. At the time, Marty Davis chimed in on his web site and supported the legality of the boat and after that all of the controversy seemed to go away. Brian Blazer's comment is correct because I raced that boat for a season and not much was said. At the season end when I set the record, boy that's when I got blasted. I have not raced much for the last 7 years and now some guys are coming up with similar designs to what I did back then and here we go again.

As far as some of the comments about non trips having to run the entire tunnel of the boat. I have to disagree. That limits any creativity with the class. How about limiting transom widths? It would be hard to do, but come up with a rule for how the deck flows into the sponsons. It is a fine line and would be hard to put into writing.

By the way Brad and Terry, good luck with your designs. I'll tell you that a light sport boat that comes from a rigger design is probably going to be a lot harder to trim than you think. The running characteristics once you start filling stuff in change big time.

It kinda goes back to the real boats past and present....which is what sport hydros are supposed to look like.....and that is what the class should be about...using one's imagination by researching full size boats as a guide....there were full size 3-point hydros that had NO non trips, much less partial nontrips.....as well as air traps ..some designs had none as the boats were designed and balanced in such a way that they simply were not needed....The sport hydro class should be the one class where one could see all kinda different designs racing against each other..not just another spec class....I still say i would LOVE to see someone design a COMPETITVE front engine conventional picklefork hydro of the early 70s era on the top side, using modern hull design technology on the bottomside..what i sleeper that would be! Im trying to come up with something, but it is a challenge! I know there are people far more capable then me that could do it! There is nothing wrong with thinking outside of the box as long as you are within in the rules....

bill that might happen sooner than later..lol

terry

JUST DO IT MAN!! :lol: :lol:

 

[Bill Gibson]

If I understand this correct if he would fill in this erea he would be OK. Am I correct?
Bob

Sorry, that does not fix it.

Mark, im asking this question out of pure ignorance...if he made that particular change to the boat, what is left that he would have to change to the boat to make it IMPBA legal? I think I mentioned it before, but im a NAMBA guy...I just think that this is a very interesting subject...perhaps a good education even! For what its worth the sport 20 that i scratch built and raced for a coupla years also has sponsons on it that were built seperatly and then attached to the tub...absolutly nothing wrong with that at all!

 

[TERMINATOR]

If I understand this correct if he would fill in this erea he would be OK. Am I correct?
Bob

Sorry, that does not fix it.

Mark, im asking this question out of pure ignorance...if he made that particular change to the boat, what is left that he would have to change to the boat to make it IMPBA legal? I think I mentioned it before, but im a NAMBA guy...I just think that this is a very interesting subject...perhaps a good education even! For what its worth the sport 20 that i scratch built and raced for a coupla years also has sponsons on it that were built seperatly and then attached to the tub...absolutly nothing wrong with that at all!

bill i went ot the archives of this tpic from another builder and he was getting the third degree by a few of the people that seem to run together on here.. all i could find as far as being explained they want to see a continuious run from the area where the sponsons attatch to the transom and no cutouts behind the sponson area.. something my hull does not have.. the rules are so vague so i feel it will be ok, but like i said it is heading to the tech directors hands for his approval ..not the ones on here that make rules up in their heads or have their own interpritations of what the vague rules that give no demensions and little clairification..lol

tk

 

[Mark Bullard]

The rules are located in two locations. You have the Nitro Special Classes in section H. On page H 7 you have these rule for the Sport 40.

Boat Specifications

1. Boat must be inboard powered.

2. Hull must be a three (3)-point hydroplane configuration and resemble a limited or

unlimited hydroplane design of past or present, except outrigger, modified outrigger,

tunnel, or canard hulls are NOT permitted.

3. Boat must have a name, sponsor's name, logo, and/or a racing number affixed to hull

(a local, national, or fictitious sponsor name is acceptable).

4. Hull shall be a minimum of 35 inches and a maximum 40 inches in length.

5. If the bow is recessed behind the tips of the sponsons, that recess shall be no larger

than 25% of the overall length of the boat.

6. Boat must have a driver and/or simulated enclosed cockpit.

7. No part of the strut may protrude behind the transom of the boat, or have a width

greater than 9/16 inches or a length longer than 3 inches.

8. See Sport Hull pictorial for clarification.

Now to find the meaning of a (3)-point hydro we must go to the Technical Standards in section K for the definition and restrictions of a hydro, page K 7. In the (a) section of those rules you will find the 3-point suspension hull. And it states;

a. 3-Point Suspension Hull: Will have two individual steps separated by a continuous

"hull". These steps shall terminate at or before "hull" midpoint. The hull must be

continuous with no steps or extra planning surfaces aft of hull midpoint. Air trap devices

shall be a maximum of .125" across the bottom surface for engine class B or larger with

no restriction on depth. Airfoils, wings, air dams, ground effects devices, etc., shall have

no limitation, considering no hydrodynamic support is gained from the device. See Nitro

Special Classes, “Sportsman Hydro” for Additional Specialized class boat specifications.

It states that the boat, "Will have two individual steps separated by a continuous hull. These steps shall terminate at or before hull midpoint. The hull must be continuous with no steps or extra planning surface aft of hull midpoint". I have said this many times the the key word is "continuous". The definition of continuous is to marked by uninterrupted extension in space, time or sequence. Or the definition of "continue" is to maintain without interruption a condition, course, or action.

In drawing to draw a continuous line is to draw a straight line or a uninterrupted line with no intersect.

These pictures show sponsons connected to a continuous hull. Or hull parts that have a straight continuous line





On Brad's boat it shows the sponsons mounted to a continuous line hull. But what he did was to cut the chine in the back part of the hull with a mininum radius after the sponsons. This could have got him in trouble if he had cut the chine out in 90 degree angles or had increased the radius. It was his construction practice, but it does push the rules.



I have known the Betke"s for a long time and they are good people. I don't think that I have ever seen this boat run but it does raise the question of being legal. I would say that it is ilegal because of the sponsons mounted on 90 degree extensions from the continuous hull covered by the top deck to where you cannot see it very well. Thus this would be call a modfied rigger.



On Terry's boat, his sponsons are clearly mounted on 90 degree extensions of the continuous hull. Thus again a modfied rigger.



You see if I took one of my riggers and filled in the mounting tubes with ply flat across the bottom from the sponson to the tub. The removed the rear sponsons and added a chine from the back of the extensions over the bottom of the tubes covers to the transom. Then covered the top part to blend the top deck in then I could call it a sport boat but it would still be a modfied rigger. These boats that have these bottom made like this with their tops blending in the pieces are modfied riggers because their sponsons are not connected to a continuous hull. This is why this rule is wrote this way and there is nothing vague about it. I know that you may not know that is what your building but I do know why you are building it this way. This is why Pinckert build the first out riggers by mounting the sponsons on some sort of extension from the hull. To remove some of the air out from under the boat.

 

[P THOMAS]

It states that the boat, "Will have two individual steps separated by a continuous hull. These steps shall terminate at or before hull midpoint. The hull must be continuous with no steps or extra planning surface aft of hull midpoint".

First part of that describes the two front running pads (steps) with a hull between. The second part refers to no rear sponson pads.

If there is NO open space between the sponsons and hull as a rigger has with boom tubes, how can it be a rigger design?

Mark You are saying that,, there has to be countinuous line with no steps across the bottom of the hull between the front sponsons?

You say that you cannot have front sponson pads offset further out than the main hull?

 

[Brad Christy]

Guys,

When I was designing and building my boat I referred to the five sections as a center section, two airtraps and two sponsons. That said........

The way I would interperet the wording of the rules is this: If any portion of the sponsons are left "hanging" behind and below the "continuous" hull, or the airtraps they are attached to, that would make for a "modified outrigger". Also, there can be no change in "elevation" between the center section and the airtraps aft of where they combine to create the continuous bottom. In other words, you cannot have airtraps that are raised (from the bottom) between the center section and the sponsons, what would basically be a single "boom" (essentially what Terry has). I hope what I'm saying here comes across as I intend it. As a friend of mine says, hope you undestand, not sorry if you don't.........

I am not interpereting the rules based on my design, but rather the other way around. Dennis Wright and I had a rather lengthy phone conversation, attempting to interperet the rules, and this is what we came up with. Dennis was by no means in a position of authority then (or now), but he had been running sport boats for quite a while and he understood where I was headed. Wrapping up our conversation, Dennis insisted I send my preliminary and final drawings to Ron Z. and John E. before beginning construction, which I did. I began construction upon their approval. The rest is, as they say, history....

Thanks. Brad.

Titan Racing Components

BlackJack Hydros

 

[P THOMAS]

Good grief now it clear as mud thanks I don t care if the sponsons and hull dont line up or not.

If it dont have clear space between the sponsons and hull it is a sport boat.

Riggers are designed with outrigger sponsons on boom tubes to rid them of lift and drag.

Any solid structure between the sonsons and hull will cause lift and drag no matter what size and shape it is, that is the challange of building a sucsessful sport boat.

Just let the tech guys decide

I think they should ask is this a rigger with open space between the hull and sponson?

Is this a rigger with covered over tubes?

If NO It is a sport boat.......

 

[LarryConrad]

Good grief now it clear as mud thanks

Phil,

Delete all your SS pictures! If he starts drawing lines on yours, they won't be legal either! :lol:

 

[Bill Gibson]

A "continuous line is not necessarily a straight line......a line at an angle or a sweep can continue forever or a least enough to meet the rear of the sponson.....been done with full size boats also......just a thought.....

 

[Mark Bullard]

Good grief now it clear as mud thanks

Phil,

Delete all your SS pictures! If he starts drawing lines on yours, they won't be legal either! :lol:

Phil's boat has aways been legal. His sponson connects to a continuous hull. Now he does use cutouts above the attachment of the sponsons but they are above the mounting point.

To answer Phil's question. Have you ever seen a hydro called a Wing-Ding? There are a couple of pictures in a old IMPBA rule book I have of Mike Meelbusch and Gary Preusse each holding one in the Hall of Fame. The sponsons were connected to the hull by way of a one piece mount. Those mounts did vary in size and lenght over the years of that boat running but they were solid. Would this be called a sport hydro?

 

[Mark Bullard]

A "continuous line is not necessarily a straight line......a line at an angle or a sweep can continue forever or a least enough to meet the rear of the sponson.....been done with full size boats also......just a thought.....

Very true. A arc or any line in a straight line is a continuous line so long as it is in between endpoints or intersects.

 

[LarryConrad]

Good grief now it clear as mud thanks

Phil,

Delete all your SS pictures! If he starts drawing lines on yours, they won't be legal either! :lol:

Phil's boat has aways been legal. His sponson connects to a continuous hull. Now he does use cutouts above the attachment of the sponsons but they are above the mounting point.

To answer Phil's question. Have you ever seen a hydro called a Wing-Ding? There are a couple of pictures in a old IMPBA rule book I have of Mike Meelbusch and Gary Preusse each holding one in the Hall of Fame. The sponsons were connected to the hull by way of a one piece mount. Those mounts did vary in size and lenght over the years of that boat running but they were solid. Would this be called a sport hydro?

Just a little humor to lighten up this thread. I had to "modify" my SS45 at a race last year to make it legal. Instead of drawing a continuous line around the windshield area on the cowl, I used a piece of black tape.

 

[DON MAHER]

Just a different view. <_<

" a. 3 point suspension hull: Will have two individual steps separated by a continuous hull "

The key word is "separated" NOT "attached" by a continuous hull. An outrigger without rear sponsons is a 3 point

"separated" by boom tubes. This rule does not say how to "attach" the two individual steps. Now we all know that on a

sport boat they are attached by the top deck.

Don

ps. another though, to modify an outrigger, you first have to have an outrigger

 

[P THOMAS]

Just a different view. <_<
" a. 3 point suspension hull: Will have two individual steps separated by a continuous hull "

The key word is "separated" NOT "attached" by a continuous hull. An outrigger without rear sponsons is a 3 point

"separated" by boom tubes. This rule does not say how to "attach" the two individual steps. Now we all know that on a

sport boat they are attached by the top deck.

Don

ps. another though, to modify an outrigger, you first have to have an outrigger

Don you Namba guys have a bit more liberal design rules But you also require the pipes to be covered unlike IMPBA rules.

heck the prez of IMPBA ran his sport boat with just a cowl over the fuel tank for some time before he got a replacment cowl and they worry about the look of terrys new hydro. :lol:

 

[P THOMAS]

Good grief now it clear as mud thanks

Phil,

Delete all your SS pictures! If he starts drawing lines on yours, they won't be legal either! :lol:

Phil's boat has aways been legal. His sponson connects to a continuous hull. Now he does use cutouts above the attachment of the sponsons but they are above the mounting point.

To answer Phil's question. Have you ever seen a hydro called a Wing-Ding? There are a couple of pictures in a old IMPBA rule book I have of Mike Meelbusch and Gary Preusse each holding one in the Hall of Fame. The sponsons were connected to the hull by way of a one piece mount. Those mounts did vary in size and lenght over the years of that boat running but they were solid. Would this be called a sport hydro?

Yes I have raced wing dings They were outriggers, they had sponson mounts not tubes. The mounts were not part of the hull just like boom tubes.

What part of this dont you understand? It is alot better than all that you are trying to say and are way overthinking the rules.

If it dont have clear space between the sponsons and hull it is a sport boat.

Riggers are designed with outrigger sponsons on boom tubes to rid them of lift and drag.

Any solid structure between the sonsons and hull will cause lift and drag no matter what size and shape it is, that is the challange of building a sucsessful sport boat.

Just let the tech guys decide

I think they should ask is this a rigger with open space between the hull and sponson?

Is this a rigger with covered over tubes?

If NO,,, It is a sport boat.......

PHIL T

 

[DON MAHER]

Phil,

I totally agree! :lol:

Don

 

[TERMINATOR]

Phil,I totally agree! :lol:

Don

thanks guys ..no boom tubes in mine.. phil i know there are none in your and i have a continuious line from the sponsons to the rear like somone is worried about ..it does have a angle in it but big deal..it is being packed up tonight and heading for "somewhere" tomorrow..and i feel confident it will come back with the stamp of approval.

terry

 

[Bill Gibson]

Just a different view. <_<
" a. 3 point suspension hull: Will have two individual steps separated by a continuous hull "

The key word is "separated" NOT "attached" by a continuous hull. An outrigger without rear sponsons is a 3 point

"separated" by boom tubes. This rule does not say how to "attach" the two individual steps. Now we all know that on a

sport boat they are attached by the top deck.

Don

ps. another though, to modify an outrigger, you first have to have an outrigger

Don you Namba guys have a bit more liberal design rules But you also require the pipes to be covered unlike IMPBA rules.

heck the prez of IMPBA ran his sport boat with just a cowl over the fuel tank for some time before he got a replacment cowl and they worry about the look of terrys new hydro. :lol:

Its a rule i just dont understand.....its stricter on sport hydros than scale hydros..AND there are tons of sport boats that run with a little bit of the pipe showing anyway....the rule makes it very difficult to cowl over a nitro pipe with an add on muffler.....whatever happened to "an effort should be made".... some of this stuff just doesnt make sense no matter what organization you run under.....but i guess you gotta have rules and both do the best they can.......

 

[Mark Bullard]

Ok guys. I have tried to help you all understand the rules but your just not listening. I am going to convert my old 20 hydro into to a sport hydro like the one you say are going to be legal. When I am done with it you will have to prove that it is a modfied rigger. I am even going to post the pictures to show you all how it is done. The boat will apear to look like Brad's boat or Mike's boat or this new boat that Terry has built. I believe that you will have a big surprize.