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Pro's & Con's between full tunnels and tunnels with center pods

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Old 11-18-2003, 08:10 AM
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I only consider a center pod when the application is single engine, to knock down the sea from the lower unit.
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Old 11-18-2003, 08:21 AM
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Super t, take a look at several single engine sub 30 foot cats,the center pod is as deep as the outside sponsons. My buddies 25 talon looks like a tricycle from the stern where as my daytona's pod is about 6 inches shallower. The Howard cat is another I have seen with a very deep pod.

Cord,how deep is the pod on your FireHawk?
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Old 11-18-2003, 08:31 AM
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Marty, I'm not saying that cats have anything to do with the venturi effect. It was just an example to illustrate how a difference in height affects air flow. Like that center board on F1 cars disturbs the venturi effect, a center pod will disturb the air flow and the air cushion in cats. I still maintain that a center pod will decrease lift as it is much easier to create a constant air cushion with a flat surface, ie. without the center pod. But true, I work with V bottoms only and I am not a cat specialist really. It would be nice to hear from someone who has some real experience and not only theoretical banter...
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Old 11-18-2003, 08:46 AM
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Excuse me. At least I own a cat, really. I have owned a single engine 30' Cobra true tunnel cat for over 6 years. I live and breath these boats. 'Theoretical banter', get a life.
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Old 11-18-2003, 08:57 AM
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Hey Marty, that was not aimed at you. It was aimed at none other than myself. No reason to get excited as I am the first one to admit that if I have some theoretical knowledge about those things, I do not have any real experience in designing or building those things. So let's keep it friendly. But this illustrates pretty well why some designers swear by center pods and others say they are detrimental. I think we all agree that a center pod does have an effect on the air flow and the cushion under the boat. It has positive and negative effects. What the net result is, positive or negative, is where opinions diverge...
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Old 11-18-2003, 09:42 AM
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Here is the back end of my eliminator. Notice the cut down center pod is much shallower then the sponsons.
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Old 11-18-2003, 10:01 AM
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Quote:
Originally posted by Airpacker
Cord,how deep is the pod on your FireHawk?

At least 1-1/2" deeper than the outer sponsons.
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Old 11-18-2003, 10:14 AM
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ST, no problem. One day let's share a pitcher of beer.
Interesting the firehawk center pod is deeper than the sponsons. Sortof like a V bottom with slots cut in. I wonder what the back end looks like at speed- Does it ride on the center pod and chine walk back and forth or does it lean in in the turns like a V?
The Eliminator at speed probably the center pod is up out of the water. A video of the rear of these boats at speed would be great.
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Old 11-18-2003, 10:39 AM
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Marty, I can tell you from the feel of the floor that the pod comes off the surface at 53 mph into the wind and 58 going with the wind.
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Old 11-18-2003, 10:58 AM
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Pictures to explain what they are talking about.

Tunnel Hull

36 skater
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