The official 36" zelos twin modding thread

[kfxguy]

Good deal. Thanks!

[Darin Jordan]

Honestly these props are so good, I'm afraid to cup them and mess them up.

Good Call. With these, it's really best to just get the next appropriate size. Looking at the latest list of what's available, it's a LARGE selection.

And, just to pass on something that I found at the 2-Lap... I was running 1815-17-45s with a bit of negative and the boat was doing OK, but as you can tell from the videos, was still getting lite in the nose (Wheelies down the front straight are fun to watch, but not fast! :) )... I had to modify them to get them to fit (hubs way too long for the stubs), but I put on a set of 1915-17-45s, which my Voracity motors will easily (EASILY) turn. The boat was clearly faster, BUT, more importantly, also keep the nose down MUCH better.

The reason is that, regardless of prop diameter, the setup is going to try to run on the last 40% to 30% or so of the prop diameter. Going larger in diameter is similar to lowering the strut on the back of the hull (something that isn't possible with this setup, only angle adjustments). Lowering the strut raises the transom, which pushes the nose down. All without any additional angle.

What I might suggest is that, if you find a props with the correct pitch (like in my case with the 1815-17-45 = 2.700" Nominal pitch), But you are having issues keeping the nose down OR would like to run with less angle in the strut, try finding the SAME pitch, but in a larger diameter prop. In the example case of the 1815, a 1914-17-45 (~2.66" Nominal Pitch) might be something interesting to try.

[kfxguy]

Good info Darin. I need to try the 1715's. I was thinking the 1814's would be good because of the additional diameter because of the slippage upon takeoff with the stock props. Did seem to work much better but maybe the 1715's will be better. I'll find out in a few weeks.

[Darin Jordan]

Good info Darin. I need to try the 1715's. I was thinking the 1814's would be good because of the additional diameter because of the slippage upon takeoff with the stock props. Did seem to work much better but maybe the 1715's will be better. I'll find out in a few weeks.

Perfect.

ONCE you settle in on a diameter that let's the boat's attitude be "right", then, with these ABCs, you can go up or down in pitch to make the motors happy.

I'm actually thinking about designing my next SAW Hydro around this theory. Not worry about strut height. Just design it around a 35mm prop and work on pitch, rake, and pitch ratios from there. Could actually eliminate the strut that way if done correctly (some German boats already do this).

[kfxguy]

Perfect.

ONCE you settle in on a diameter that let's the boat's attitude be "right", then, with these ABCs, you can go up or down in pitch to make the motors happy.

I'm actually thinking about designing my next SAW Hydro around this theory. Not worry about strut height. Just design it around a 35mm prop and work on pitch, rake, and pitch ratios from there. Could actually eliminate the strut that way if done correctly (some German boats already do this).

I actually did this with my 32" cat. I settled on the diameter that worked well and then went up in pitch as I checked logs and temps to see if the motor and esc could handle it. I'm at 98 with it and I have one more step in pitch I can go up. So that theory does work well. I was doing that and didn't realize it till you just said something. Lol

[Darin Jordan]

I actually did this with my 32" cat. I settled on the diameter that worked well and then went up in pitch as I checked logs and temps to see if the motor and esc could handle it. I'm at 98 with it and I have one more step in pitch I can go up. So that theory does work well. I was doing that and didn't realize it till you just said something. Lol

There is a LOT to be said about the "guess and check" method! That's how most of the S/W around here (at work) gets developed!

[Keagan-Z06]

Got lucky today and got my Zelos cleared from customs! Having a hard time getting my flex shaft loose to grease them. Tight space!

[Rafael_Lopez]

Got lucky today and got my Zelos cleared from customs! Having a hard time getting my flex shaft loose to grease them. Tight space!

Are you using 2, 10mm open end wrenches?

I haven't heard this from anyone else. Can someone else tell me if you are having trouble accessing the motor coupler with 2 10mm open end wrenches?

[srislash]

Perfect.

ONCE you settle in on a diameter that let's the boat's attitude be "right", then, with these ABCs, you can go up or down in pitch to make the motors happy.

I'm actually thinking about designing my next SAW Hydro around this theory. Not worry about strut height. Just design it around a 35mm prop and work on pitch, rake, and pitch ratios from there. Could actually eliminate the strut that way if done correctly (some German boats already do this).

This is what I have been doing, it just changes the attitude too much going up in dia. Kind of came upon it accidentally. Sorry to come in here halfway Darin/Travis but I've been meaning to subscribe.
No Zelos here yet but this is what's been working on the Fantasm.

[arrover]

Are you using 2, 10mm open end wrenches?

I haven't heard this from anyone else. Can someone else tell me if you are having trouble accessing the motor coupler with 2 10mm open end wrenches?

I haven't had any difficulty getting the couplers loose although they are located in a more confined space than say the Voracity. It's just the nature of the beast. The cooling lines and water pickups are somewhat in the way when I wipe the grease off the tip of the flexes. On my boat the stuffing tube liner was longer than the brass tube. I cut the liner off flush so I have a little more room to get my rag in there to wipe the tip of the flex off before inserting it into the coupler. It takes more time to do the maintenance on this boat and that's just natural since it has twins.

[Keagan-Z06]

What size wrenches are you guys using? I won't be able to get the flex shaft greased until Monday evening. I used 7/16 and a wrench on the voracity but can't on the Zelos.

[modvp55]

One thing I found on real boats that sounds like is working here as well is that high rake props (bow lifting at neutral trim) with the right amount of negative trim actually generate tail lift because the narrow cone is being thrust into the water. We found that to work best at 1/2 to 1.5 degrees of negative, if we needed more negative we then would decrease the rake until we got into that range. Difference to this is we also had the ability to change prop shaft height. Darin is correct most of the work that the prop does is the outer 40 percent, when we broke props 90 percent of the time it would be in the same place.

[Rafael_Lopez]

What size wrenches are you guys using? I won't be able to get the flex shaft greased until Monday evening. I used 7/16 and a wrench on the voracity but can't on the Zelos.

The Voracity 36 and the Zelos 36 use the same motor coupler. They are metric; 10mm.

[Keagan-Z06]

Damn it! Don't think I have a 10mm wrench.

[Rafael_Lopez]

That's one of those silly details I put in the manual, lol