Dual water pickup rudder 4 or 5 inch?

[Deepvee]

Hey Guys,


I was going to get the dual water pickup rudder ( straight blade)from OSE, but wasn't sure if I should go with 4 or 5 inch set back?

Any thoughts?

4 inch seems more of a stock setup. I know JPriami runs a 4 inch and it seems to work well. I'm leaning towards 5 myself.

This will be my first upgrade besides 6s lipos
Thx guys

[Spartan]

Hey Guys,


I was going to get the dual water pickup rudder ( straight blade)from OSE, but wasn't sure if I should go with 4 or 5 inch set back?

Any thoughts?

4 inch seems more of a stock setup. I know JPriami runs a 4 inch and it seems to work well. I'm leaning towards 5 myself.

This will be my first upgrade besides 6s lipos
Thx guys

I'm running a 5in. From sht I can tell it is Alot more smooth in the water.

[fidelity101]

I purchased this: http://www.ebay.com/itm/Hot-Racing-T...-/291382297455

The problem is that the water stops flowing once I pass 50% throttle, which means temps go up quickly. I've tried reaming out the intake holes and even adding more of a tear drop shape to the front of the holes, but I'm starting to wonder if I need a better rudder or maybe I should go with a different type of water pickup and fill in the holes on the rudder.

How does the 5" rudder work in terms of water flow at speed? I'm going with a Leopard 1600kv motor and 180A ESC so the speeds will be higher meaning water intake will be critical.

[Make-a-Wake]

Deepvee: Would a 5 inch setback interfere with the prop? Where would the trailing edge be in relation to prop?

[fidelity101]

From experience with my KBB 45 Mystic, I know the further back you go from the transom the wider the runs. This doesn't really matter much at speed but slow speed turning can be negatively affected. I would imagine that a longer distance would translate into larger inputs being required in order to turn, which might actually be a good thing as speed.

I need to figure out why I'm not pulling water at anything over 50% throttle...and why I'm getting the occasional chin walking at speed. Sometimes it runs perfectly and some times in chin walks like a mad man.

[SpartanDriver]

I have my external from rudder. I was having heating issues so I mounted mine to the back of the hull (both of them) and my heating went away. They are 1/4 inch below the hull. this would be my first spartan boat. The second one has a Rio dual rudder assembly that I modified for the pickups I have pic in my Album you can look at. and it feeds the motor, esc, and caps, plus batteries. The Rio rudder assembly you can from Kintech that is where I got mine. NO HEAT lol

[fidelity101]

I'm still not sure why my dual rudder pickups can't grab water at anything past half throttle. I've added tear drop shapes to the intake and everything looks good tubing wise. I have 4-5 external water jackets and some in hull water pickups I might try if I can't figure this out. I'll just put the original ridder back on and add a second water intake.

Also, your album doesn't have any pictures

[Spartanator]

I'm still not sure why my dual rudder pickups can't grab water at anything past half throttle. I've added tear drop shapes to the intake and everything looks good tubing wise. I have 4-5 external water jackets and some in hull water pickups I might try if I can't figure this out. I'll just put the original ridder back on and add a second water intake.

Also, your album doesn't have any pictures

The rudder outlets are not in the water or you cannot see the water exiting the outlet due to high speed.

[SpartanDriver]

OK don't know why my album isn't showing anything, will work on that later. This is the back of my boat 20150222_112124a.jpgSpartan boats (0).jpg and side. I added a weight to keep the rear area in the water for the water pickups to work. It is a boat not a plane lol.

[Spartanator]

Your album works for me.

[Dominick]

How did your boat run with the new 5 Inc rudder?

[Deepvee]

5 inch runs great! Super stable and turns on a dime!

[fidelity101]

Our lakes are finally thawing out...maybe I'll be able to do a test later this month. :) The 5" rudder looks like it has larger holes than the lower quality rudder I picked up from ebay. :)

[Deepvee]

Our lakes are finally thawing out...maybe I'll be able to do a test later this month. :) The 5" rudder looks like it has larger holes than the lower quality rudder I picked up from ebay. :)

I will also chime in and drop a picture of mine. I have decided to go with a 5inch setback with a 5inch rudder. IMHO I believe Speedmaster to make some of the finest quality stuff! I have upgraded a lot of the back end with there products and am very pleased. The rudder is very exceptional for cooling as well as a great improvment in steering response.

Here are some pictures of my Spartan with the upgrades now completed.

IMG_3437.jpgIMG_3440.jpgIMG_3442.jpgIMG_3445.jpg