302Sport

I want to hear your input.......

SVL-WARLOCK

It depends on your bottom. By mounting them straight you are trying to extend the bottom with out actually doing it. That is why you need to be able to mount it straight along the chine.

Gladhe8er

I would imagine it depends on the boat. Most are even with the bottom of the hull but I have seen Warlocks and others with them mounted parrallel with the ground/water.

302Sport

all the new fountains are straight across, i was wondering what are the advantages of that??????? has anybody switched theirs and compared how the boat changed????

Too Stroked

A properly mounted set of tabs will either help you get up on plane and / or fly the boat at a desired level / attitude. They can also effectively lengthen your hull by the length of the tab – for a lot less money than a longer hull.

The theory used to be to mount the tabs parallel to the running surface – and this still works pretty well on many boats. There are some watch outs such as mounting the tabs up the transom a bit so as to avoid adding drag even when in the up position. The same goes for setting the “full up” angle.

On high performance boats though, you want all of the good stuff a set of tabs provides – with the least possible drag. That’s where mounting them “straight across the transom” comes in. The theory - as I understand it - is that when you mount them this way, the water contact patch (and thus friction) is reduced because it’s only contacting part of the tab. Less friction = less drag = more speed.

On Fountain powerboats, they used to all come with the tabs mounted level with the planning bottom. Then we started to see some mounted straight across. The rumor I heard was that the first time Reggie saw a set mounted the new way, he fired the guy. Then they discovered the extra speed angle. Every one I’ve seen lately is mounted straight across.

Hope that helps.

SVL-WARLOCK

Baja did this in the late 70s early 80s. Warlock started doing it in the mid 90s and when factory racing became big people saw the benefits and started doing it.

DMOORE

Mounting straight across also make the "engagement more progressive, since the outside corner is the first part to touch the water, instead of the entire tab.

Darrell.

sinus

Which position is better for chine walk?

Too Stroked

True for some boats, but not for all. In 1992, there was a 22' Progression on the cover of Powerboat magazine. (That's where I fell in love.) It had a set of K-Planes mounted at the outside chines - parallel with the bottom. After Kevin built that boat - which was later raced - he found that at least with a 22' Progression, that part of the boat is rarely in contact with the water. So, one ended up dropping the tabs more than was actually needed. Then when you actually hit a big wave and then "engaged" the tabs, you took a nose dive.

Having heard this, I mounted the tabs on my Progression (the next 22' out of the mold) level with the bottom, but over the first set of lifting strakes. Pictures of my boat at full speed show that even that location is out of the water much of the time, but not so much as at the outside chines.

If I were to mount tabs on the boat today, I'd go parallel with the water and at the same location. For bigger boats, I'd go parallel with the water - but at the outside chines. Like somebody said, that's where you see them mounted on the newer Fountains.

scarabman

iTrader: (1)

Parallel to the water is usually considered better for chine wlking situations. When mounted parallel to the bottom, depending on the amount of deployment the tab can actually accentuate the chine walking problem.