Tunnel Tab?

07-03-2002, 10:34 AM

I am looking for opinions on Tunnel tabs when used on 30 Spectre however all experiences are welcomed?
What are the different makes that will fit this application?
What is the down side to not having one?
Is a Tab necessary?
Are there Alteratives?
Approximate Price?

07-03-2002, 11:33 AM

What nobody has an opinion?

Cord · 07-03-2002, 12:02 PM

I do know that there was a halfway decent thread on the...um...hot boat board. Look under cats.

07-03-2002, 05:37 PM

I understand theres a New
Flex tab that make the
Re-Entry a lot smoother,
Best hope some of the Cat
Men can give you some Help
Mike J.

Tbonepmp · 07-03-2002, 06:06 PM

I AM CURIOUS ABOUT THIS AS WELL...
HELP....HELP....HELP....HELP......HELP.....HELP

Philip · 07-03-2002, 06:35 PM

I only have exp. with Skaters, 28' and 32' both (2) eng. outboard.
I see no reason to have a tunnel tab, or tabs at all. (2) of my friends both have 30' Spectre's, one a outboard, and the other one a Inboard. neither have tabs, and we have discussed this option many times, neither think their boats would benifit, I have run a 28' Skater with a Tunnel tab, and the added weight at the stern hurt the balance. These are just my thoughts, and I am not as expert on Spec. by any means, KenP has a 30' and he is the man to speak to.
Philip

Cord · 07-03-2002, 06:46 PM

How would the the weight throw the balance off? From my understanding most tunnel tabs use fixed turnbuckels. Maybe 10lbs each?

CigDaze · 07-03-2002, 08:00 PM

The flex tabs are really nice.

They are composite in design, cored with some kind of nomex felt encapsulated with either Kevlar or S-glass. They are flexure plates that behave much like a cantilevered beam with a point load near the end. The plate's don't hinge on a single point like most tabs and are do not act infinately rigid.

The plates curve and flex hyperbolically, giving way to a revolutionary way to create precise control surfaces with a more pronounced boundry layer that reduces shocks and improves the boundary layers....Great for 'intelligently' adjusting to pressure loads and changing angles of attack both hydrodynamically and aerodynamically.

We've done a lot of work on similar control surfaces on some up and coming military aircraft. The numbers prove the design.

I saw a few cats with these tabs in Daytona. I think they are working.

Sonny Spectre 30 · 07-03-2002, 10:24 PM

I have a 30' Spectre I/O with the tab offered by the factory. I am glad I have it. It allows you to dial out any mid range porpoise you might experience with your boat. I run it completely up at top speed and completely up at low speed. If you want to go really slow (20MPH) and stay on plane-use the tab and you can.

Hope this helps.

Sonny

Flashback · 07-03-2002, 10:42 PM

I need a tunnel tab for my Chris Cat to eliminate the porpoise that starts in the high 90's. Dueclaws had talked to George Linder the designer of the Chris Cat about this problem on his Cat on a post some time ago. George recomended the tab. Does anyone know if Duelaws has installed the tab on his cat and or, if it works well? The tab is supposed to add aft tunnel compression as the cat tries to balance out hydrodynamics/aerodynamics