Rigging K-Planes
 

If we have covered this subject before, forgive me, as my memory is not as good as it once was...

I see that the K-planes are not being mounted parallel with the bottom of the boat on the new Y2Ks.
Why not?

I may be able to answer my second question. Why are the inner ends of the K-planes being trimmed? Is it because the prop might hit them?

And is it best to have the trim tabs mounted as far outboard as possible?

Re: Rigging K-Planes
 

I think this was talked about somewhere - my understanding is that the tabs should follow the angle of the Vee otherwise some racers have noted level placement causes squirrely effects at high speed.

Technically, My tabs can indeed still hit the prop, even after they have been trimmed. However, the drive would never be engaged in this position - I would have to be 100% trimmed (as in trailer full up) and the wheel turned to a right lock - I hope I never have my prop turning in this config! BTW, I once tried to trim them further, but my jigsaw blade only scratched the surface!!! I gave up and touched up the paint......

As for placement outboard, I can't answer that except in theory - that would allow you the shortest movement for the fastest tab effect.

These all sound like great Superfest topics over a cold one!!! I'm trying to see if I can make it, but not looking good right this moment, hope I can change some things......

Re: Rigging K-Planes
 

JCAP said that he wiped out a good prop by hitting the k-plane.

Re: Rigging K-Planes
 

I took a chunk out of a a brand new labbed merc. 4 blade on the great south bay...................then my tabs were cut.

Re: Rigging K-Planes
 

JC cut my tabs after Superbabi whacked his. I have the ITS and From what I can tell the prop being 7 1/2" further back I dont think they needed to be cut. BTW Ive seen a lot of fountains that have them mounted horisontal

Re: Rigging K-Planes
 

I've seen a couple of Kryptonites with them horizontal too.

OK guys we still don't have the theory bind this...
FX-10, Lightspeed, Fasteddy, Zuperboat where are you?

Re: Rigging K-Planes
 

Pat , just call JC :eek:

Re: Rigging K-Planes
 

Naaaaa...
What fun would that be? :p
Besides, do you think he knows?
Gary,
I did ask his when I saw your boat in the rigging shop.
I don't recall much of an answer... :rolleyes:

Re: Rigging K-Planes
 

Pat so real, and so true, and by all means so funny !!!!

Re: Rigging K-Planes
 

I suppose to exert less drag pushing straight down as opposed to pushing out to the sides

Re: Rigging K-Planes
 

I guess JC's theory is to jus-slap-em somewhere in the middle to make everyone happy :rolleyes:

Re: Rigging K-Planes
 

Do you think the last 4-5 Y2K'S tabs are all in the SAME PLACE ????

Re: Rigging K-Planes
 

Tabs in my opinion should be as close to the center of the V as possible because when the boats flying on the pad or inner chines the tabs will not have to move alot to be effective. Now horizontal I think would make the boat more stabile for chinewalking and when you hit a turn you have something extra to help carve the turn instead of just sliding. When my boat was a bravo the tabs where in close, during the conversion to the speedy and the very short #4 drive enabled me to lower the motor in the boat almost 2 inches and still have a good X dim. In turn lowering the location for the stearing rams so the tabs had to be move out and with the bottom. Im not a racer so this is just speculation.

Re: Rigging K-Planes
 

Well here are where mine are located.

Re: Rigging K-Planes
 

Same as mine

Re: Rigging K-Planes
 

OK Zuper,
I agree that having the tabs more inboard would have them engage the water sooner when the boat is running high.
I'm still struggling with the horizontal thing though.
I guess with having a notch in the transom, the water is going to come off the boat differently. I don't see it being better on a straight V with no notch.
Also, to your carving vs. sliding comment: I would think having the tabs more toword the keel would help there too. But having them horizontal would have them engage less in a turn then if they were parallel with the bottom.

Hey Lightspeed,
No expert insight for us?

Re: Rigging K-Planes
 

Pat it depends on the tab your talking about. On turns the highside will be out of the water.

Re: Rigging K-Planes
 

I follow you Zup, the lower tab would have a better angle to bite in a turn...

Re: Rigging K-Planes
 

All I can Tell You Is I Dont Agree Where JC Wanted Me To Put The Tabs .I Have Always Put them 1 Inch Above The Bottom Same Angle As The Bottom And After Running The Boat to see If They Scrubbed Any Speed I Took The Pins Out took The tab Bottoms Off And Reran The Boat No Speed difference Ran The Same. The other way You Have To Put Too Much Tab Down To Contact the water Which Is A No no when Runnin In Big Seas Thats My Two Cents They Will Be 1 Inch Above On My Boat

Re: Rigging K-Planes
 

Hmmm...

So it's all about speed... :evilb:

The picture is now becoming clearer... :cool:

With the tabs mounted horizontal less speed will be scrubbed as they are lowered.
With tabs mounted with the angle of the bottom, and then dropped below neutral, lots of drag is added. With both tabs lowered below neutral they will act together like a parachute.

Hey Light Speed,
I do remember seeing the K-plane mounted horizontal on two Kryptonites. Is that the norm from the factory?

Re: Rigging K-Planes
 

No Pat You Got It Wrong They Still Scrub Speed When Lowered In Both Positions ..You Use Less Tab And You Have More Surface When Mounted With The angle Of The Boat ..Where As If You Put them Horizontal You Have To use More Tab And Your Only Hitting the tips On The Water ..Your Not Using The whole Tab ..Well Just theory

Re: Rigging K-Planes
 

Lightspeed,
No doubt you scrub speed in either configuration when you drop the tabs. And I do share your opinion that mounting with the angle of the boat is better/more stable. And if you run with the tabs at neutral, it's like adding 2' to the length of your boat..
However, with the tabs mounted with the angle of the boat, and both dropped below neutral, they will act like a sea anchor and grab the water. Hold your hands like they are trim tabs and bend at your wrist; they will angle outward, grabbing the water like brakes.
Now with the tabs horizontal, parallel with the water, as they are lowered they push the stern up with a more vertical force. The tabs don't work together to cup the water so to speak.
I believe I do now understand why tabs are now sometime mounted horizontal. Anyone else buy into my theory?

Re: Rigging K-Planes
 

Seems like a catch 22 to me... If a tab is mounted horizontal it will cause less drag when lowered but will also not work as well because of less contact being made in that lowered position. The way the theory was explained to me is very similar to what Lightspeed said, the tab is mounted at the angle of the hull to make contact w/ the water and influence the ride with as little down travel as possible. Think about this also: in either case the bow being forced down would cause more drag then the placement angle of the tabs in either set-up.

Re: Rigging K-Planes
 

Well said Huntington...
So how are you going to have JC mount your K-planes?

Re: Rigging K-Planes
 

Here we go again..........sure would be nice to get it right...........and than just repeat the process. Good luck Rob.

Re: Rigging K-Planes
 

Gary,
It looks like JC had JD mount the tabs on your boat in the middle somewhere; a happy medium maybe?
JC runs all the boats that come out of his shop so he knows what works and what doesn't...

I started this thread to discuss the theory behind tab location and angle. I don't think we have in said that mounting the tabs more toward horizontal is wrong, just different...

Re: Rigging K-Planes
 

Fountain Is Doing Well These Days In Races Maybe We Should Ask Reggie. Common Lightspeed Ask Him , Ive Seen His Helicopter In Your Yard. We All Know Your A Spy For Reggie Stealing Superboat Secrets From John.

Re: Rigging K-Planes
 

Yea lightspeed, stealing all those TRADE SECRETS from JC, Shame on you !!!!!! lol lol :D

I am a believer in the "mount the Tabs flat", but only if they are 380's (long ones).

If you do this, you better make sure of a couple things.

1. Make sure your boat doesn't have a hook in the hull.

2. Make sure your engine is in the right place.

The correct "Center of Gravity" is very important, or else it will be an unstable situtation.

If done correctly, the "tabs flat" set-up will be faster... :drink: