why dont turn fins and trim tabs have water pickup's built in like rudder?

[dana]

just curious

[Diesel6401]

just curious

Well Kintec sells trim tabs with pickup, as far as turn fins I know I don't over tighten my turn fins so if I would hit something they can kick far out and I'd imagine they would kink or pull off a cooling hose. Just my 2 cents.


Kintec trim tabs

[Doby]

I have an Aquacraft V-24 that has them built into the tabs. They work great!

[Diesel6401]

I have an Aquacraft V-24 that has them built into the tabs. They work great!

That's pretty cool...

[m4a1usr]

Why dont turn fins and trim tabs have water pickups built in like a rudder?

The answer is very simple. You need one water pickup location for bringing cooling water for most applications. If you decide on a trim tab pickup then its doubtfull you need a rudder pickup too.

The rule to remember is water follows the path of least resistance. If you have 2 or more water pickups and one of those is not submerged or in the water path the incoming water pressure will exit the location closest to it.

An example would be using a trim tab water pickup and rudder pickup. As long as the water pressure into both pickups was equal you would get flow thru the tubing to your esc and motor. But make a turn where the trim tab leaves the water and with the rudder submerged you will be dumping most if not all the water out of the trim tab pickup and getting little to no flow thru your esc and motor.

Dont complicate things with the idea more is better. Its usualy not true. KISS is a pretty darn good rule to follow for the most part.


John

[ncornacchi]

Dana, Grab that custom rudder off Leon if he hasn't used it...I had them made to fit the stock hardware on the UL1....The guys are right though,,,,although my temps are always super cool, I think i've sacrificed a couple mph drag because of 2'nd pickup built into rudder....But personally, I'd rather keep things cool for long runs and give up a couple mph's..

[properchopper]

Why dont turn fins and trim tabs have water pickups built in like a rudder?

The answer is very simple. You need one water pickup location for bringing cooling water for most applications. If you decide on a trim tab pickup then its doubtfull you need a rudder pickup too.

The rule to remember is water follows the path of least resistance. If you have 2 or more water pickups and one of those is not submerged or in the water path the incoming water pressure will exit the location closest to it.

An example would be using a trim tab water pickup and rudder pickup. As long as the water pressure into both pickups was equal you would get flow thru the tubing to your esc and motor. But make a turn where the trim tab leaves the water and with the rudder submerged you will be dumping most if not all the water out of the trim tab pickup and getting little to no flow thru your esc and motor.

Dont complicate things with the idea more is better. Its usualy not true. KISS is a pretty darn good rule to follow for the most part.


John

I agree with John completely on this. At best, watercooling can be viewed as a band-aid for a bad setup, and dependance on elaborate cooling schemes gets messy - too much flow leads to inefficient heat transfer, and too much pressure has the potential of causing boat-filling leaks. I'll concede that using seperate cooling circuits does have the benefit of providing non-preheated water to the second component in the flow path - usually the motor. Speedmaster-Rossi has dual-pickup rudders, but mostly in sizes suited for larger boats. A trim-tab secondary pickup plumbed separately from the rudder pickup is a reasonable way to go. I had that once on a mono I ran and worked well although it was probably unneccesary. The rudder on the new Insane Sport Hydro has two inlets - one on either side of the rudder [with a single outlet] and should provide plenty of flow. I'll be testing the boat tomorrow and will know more once tested.