Stupid Question Time

[Propjockey]

Why don't 'cats and tunnels use trim tabs?

 

[paul heuston]

i thought it was because there was more than 1 wetted surface.

i mean a mono has 1 complete wetted surface.

where as a cat has the 2 wetted surface.

same as a tunnel.

paul

if i am wrong let me know.

: : : : :

 

[Finne]

well I don't know about tunnels. But most big cats I've seen (victory team dubai etc.) have trimtabs.

I'm gona try to find a pic...

 

[Finne]

ok. finaly found a pic. not a very good one, but anyway.

http://www.xtremercboats.com/phpBB/viewtop...=846&highlight=

if you scroll down a bit you can see the trimtabs outside of the props.

I know I've seen a much better pic somewhere, but I can't find it now.

 

[Finne]

...no wait. i found it. just scroll down even further and there's a perfect pic. ;D

 

[Slideblues]

Actually a guy named Gary P. runs them on his tunnel:

 

[Finne]

hum... is that a inboard tunnel? (looks a bit like it on that pic i think)

 

[Slideblues]

Here is the full pic:

 

[MarkScott]

Stupid laws... Did ya know one could get arrested for having hemostats in some states.. Stupid, but true... Can't recall which ones though..

 

[Propjockey]

Yeah, but what does Gary know about tunnels? ;D

I mean, he's using an Elmer's glue bottle for a hopper tank...c'mon, let's get an example from someone who knows how to set up a tunnel to win! ;D

Propjockey racing....Smell the sarcasm! 8)

 

[Slideblues]

He,He,

Must run in the family, note the tank on the hull on the left!!!!!

Maybe that scary dude in the middle knows sumpin about this stuff??

Gene ;D

 

[GTR]

HI Guy's

I believe Garry P plan is that the motor is set at 0deg thrust angle for maximum forward speed and uses the tabs to control attitude, rather than tilting the motor up or down and wasting thust.

GT ;D

 

[Ian Inverarity]

I tried that years ago on my K&B 21 MRP Mach 1 so that I could control the ride with the tabs and have the motor set with zero thrust angle for better handling in the turns. From memory it worked well.

Ian.

 

[Ron Olson]

This was brought up a while ago about Gary's tunnel boat. We call them trim tabs, but what he is doing with his is moving the CG further forward making the hull longer in essence.

 

[MarkScott]

Believe the boats that have the transom moved forward does the same thing? Example would be the Octura Tom's Cat..

 

[nitrotoys]

Gary Pruesse were talking???

Sure looks like his 7.5 hawk in the back ground.

If you have ever seen him run, you tooo would put tabs on your tunnel. Hes got several speed records with K&B OBs.

that bottle on top helps fuel flow into carb.

and i think that little bit of added to the lenght of the boat, makes it handle alittle better.

I do know some CATs do run the smaller tabs like that also

 

[Finne]

Man this tunnel buissnes is confuseing.

so moveing the transom forward improves performance. but what does moveing the engine further back do?