Predator Rigger Motor selection

[j.m.]

Hey guys,

Going to start building a Predator rigger, and i am trying to decide between a feigao 540 6S and a 540 6L.

Before you jump out and say get the L, i must say that i will be running the boat on 6 GP3300's. That's it. I'm thinking the 6s would give me the RPM needed by riggers, and use an x427 on that (i'm looking for runtimes, you know.) or an x535 turned down to 530. Somebody please chime in if i'm completely off.

[toyotatruckin]

I gonna be running a lehner xl5000 in mine might go for the shorter motor not sure if the feigao L will fit with out having to make a bubble on the hatch- I could be wrong though

[Dr. Jet]

I used a Lehner Basic 5300 on 6 x GP3300s in my Silver Bullet rigger using props ranging from an X427 to an X632 (all D/T) and it was a good combination. Current draw ranged from about 45 amps to around 80 amps, depending on the prop. Speeds were in the high 30s~to mid-high 40s depending on prop selection.

[Ub Hauled]

I have used a 6S, an 8L (bigger prop) and a 1509/1D (SAW type racing).
I had a bit of heat with the 6S spinning a 632, I was told to use a 442 (that I have not).
The 8L was going good with the 632 I think it could go a bit bigger, maybe a 535 or so.
The 1509 was too fast for that hull...anyway I used a 935 and 937, it was only straight aways and not much of a turn... I think it could be due to the absence of the turn fin

Use the info if helpful BUT
I just noticed I have a Blizzard not a Predator.

[j.m.]

Well, the blizzard and the predator are basically the same. One is like 1/2" longer than the other, and has sponsons that are the EXACT same but they are 1/8" bigger all around. I think it's the predator that's a touch bigger. Probably better suited for the higher weight of Nimh cells.

I want to use a 60 amp esc, and 40mph is plenty. That said, i think that i will go with a feigao 6s and an x430. (the feigao has a tad less Kv, so more torque.)(than the lehner basic)

[toyotatruckin]

blizzard is aprox 19 3/4 long predator is aprox. 21 1/2

[Ub Hauled]

I guess my blizzard is different.. the tub measures 22". This particular one I have not
built, but it says Blizzard Custom (lasered on the bow).

[toyotatruckin]

the blizzard above I built from temps I made of an original blizzard so its an exact copy of the kit I had to the letter- sounds like it was a different kit than mine as mine didnt have custom burnt on it any place.

ok found a picture of my original

[j.m.]

gorgeous.

Does anyone have a head-on view of the sponsons?

My question is whether they are flat or angled with the outside being higher.

If they are flat, then you could make an outrigger that doesn't need a turn fin and could turn each way equally as well by angling the sponson bottoms like a tunnel hull. Not quite as steep as most, but a 10 degree angle should make a noticeable difference in turning. The problem is, you would loose a bit of lift by doing this, so the area may need to be increased.

If the bottoms were curved on the outside edge of the bottom, and then flatter near the middle, this could still work for lift, while providing adequate turning.

This is all just an idea, but i think it's a pretty good one.

[toyotatruckin]

ok hope this is what you were looking for(picture is of the predator im building)


your gonna need a turn fin no matter what you put the bottoms at (unless your running straight line) easiest way i can think to put it is------think of a mono hull--deep V vs. shallow V -- your deep V is gonna take rougher water better but wont be as fast as the shallow V the shallow V will see more speed but will fall short in rougher water.. of course there is more to it but thats the most basic way I could think to put it

mine is setting at about 1/16 off the build board both sides (outside up inside on the board)

[j.m.]

tunnel hull:

http://www.rumrunnerracing.com/articles/wavemaster/Image4.jpg

The angle of the hulls allows the outside hull in a turn to rise above the water because of it's angle, but the inside hull is sucked into the water because of the small lip on the inside edge.

This is the SAME EXACT thing that a turn fin does, but with a tunnel the "turn fin" on each sponson only works one way, allowing the hull to turn equally well in both directions. And when i say well, i mean EXCELENT!

look:

http://www.youtube.com/watch?v=ZMJ7xY9JVrE&feature=related

Not the best video, but it shows what i'm talking about.

[toyotatruckin]

only thing i can say is try it and see--always add a fin later---one big difference in tunnels and riggers is the tunnel will lay down so to say in the turns, a rigger wont.

[j.m.]

what do you mean by "lay down" in the turns?

Are you saying that they get closer to the water?

I don't think that i'm ready to try and modify the boat before i ever see how it runs in the first place. I was just posting my idea.

[j.m.]

Also, a fin in the center of the hull might help it turn both ways. Or two turn fins. (one on each sponson)

[toyotatruckin]

I can say its guys like you that keep this hobby moving forward with thinking how to improve on things.. two fins I believe would make the hull very squirrely center fin I would have no clue on how it would react--my guess it would go straight fine and would most likely not slide in the turns but not sure how you could keep it from rolling in a high speed turn as there is nothing to hold the boat down, also would need to attach it in a way so it could be moved to find the "sweet spot"