Which Motors For the EKOS?

[LarrysDrifter]

I finally get to rehab my best looking junk boat-the EKOS.Im unsure what motors to run.Should I get the 380 10xl or a 540 size motor?I do want to run 4s per motor and maybe Octura x442's.Speed goal of 50mph at least-but reliably.I was also looking at the Turnigy or Sea King esc.Hobby King is out of stock on the Turnigys and the Sea Kings look to be the same esc anyway and you get a programming card with it too.They would be 120 amp of course.Would the 380's run cooler?Id like to mess with different props but am worried the 380's wouldnt give me too many options.Any suggestions?

[Steven Vaccaro]

Shooting for 50 plus mph I would suggest the feigao 380 9xl's.

[forescott]

9xl's are the way to go. 50mph is attainable on 32mm props on 4s. Or 40mm props on 3s

[Simon.O.]

9xl's are the way to go. 50mph is attainable on 32mm props on 4s. Or 40mm props on 3s

With this setup what sort of Amps are you pulling ?
I am repowering my bigger cat (similar size to a Ekos) and the motors are on the way now but can be used eleswhere if they are not suitable.

I am keen to see what sort of amps a 40mm prop on a 380-9xl will pull ?

Watching.

[vasy]

Turnigy 120a are back in stock, go get them :)
10xl on 4s and 40 to x442 will get you your speed and stay warm.
We tested it at 50-55.
9xl should give you maybe a bit more speed but probably pull a few more amps.
on 10xl peak is around 70, but can't say average. on 40mm props passes the 10 second heat test on x442 about 7.

[forescott]

My 9xl's didnt pass the 2 second heat test on 3s and 442's. And i'm running wire drives(less friction). I need to get some data logging tools. My best top speed on the 9xl was with 40mm props on 4s @ 55.2mph.

[vasy]

My 9xl's didnt pass the 2 second heat test on 3s and 442's. And i'm running wire drives(less friction). I need to get some data logging tools. My best top speed on the 9xl was with 40mm props on 4s @ 55.2mph.

So 9xl is faster, our best recorded so far on 10xl was 51.xx I just can't recall the xx.
On x442 we had some issues with water when we tried to GPS is, it was just way to choppy for a reliable reading, we got 52 but the boat wanted to fly.

[LarrysDrifter]

Thanks for the input guys.I see the benefits with both.I want the speed but I also want the cooler running more than the speed.Which would be cooler-9xl or 10xl?

[forescott]

You would be perfectly happy with either. Kinda depends on the prop you want to use. 32 0r 36mm props=9xl. 40mm props=10xl. I would go with the 10xl. A little more torque, still plenty of speed.

[LarrysDrifter]

You would be perfectly happy with either. Kinda depends on the prop you want to use. 32 0r 36mm props=9xl. 40mm props=10xl. I would go with the 10xl. A little more torque, still plenty of speed.

Your other post said that 9xl's are the way to go.I just got done ordering the 9xl's and 32mm props.Which motor would produce the least amount of heat?I know water temps are high rite now.

[FighterCat57]

Your other post said that 9xl's are the way to go.I just got done ordering the 9xl's and 32mm props.Which motor would produce the least amount of heat?I know water temps are high rite now.

I'm willing to bet 4s 9xl 32mm prop = 51-52 MPH.

Should sound really cool at high RPM too! I'm running 2700kv 540's on 4s w/32mm props. Really neat sound and some cavitation which seems to help keep the heat down by reducing the load. Only pulling 53 amps peak. I don't hole shot it, just run it up to speed.

Should be a good setup!

[forescott]

I have the 9xl's and love em. But you said your looking for a cold setup with not so much emphasis on speed. Both motors are great and similar in performance. Dont worry, the 9xl's are awesome. Just dont try and run a 42mm prop with them. Stick with the 32 or 36mm venom 3-blades. The 10xl will produce less heat on the same prop, but 32mm props are no problem at all. I just ran my ekos a couple of days ago on the 9xl/32mm prop/4s lipos. Got 50.2 mph and NO heat. You made a wise choice. If you chose the 10xl, I would just say use the 36mm -40mm prop for similar speed/heat.

[forescott]

Are you planning on running 3s or 4s??

[LarrysDrifter]

Are you planning on running 3s or 4s??

Plan on 4s.I was on HobbyKing to get the Turnigy 120's and theyre out.Went to Hobbyhot and got the Hobbywing 120 esc's.They look exactly like the stockers.And they come with a programming card(which I only need 1).I was pretty nervous when I was buying the motors earlier.Thanks for setting me straight.Now Im on the search for two 4s batteries.HobbyKing is out of Turnigys and I dont know what size will fit.(Took the battery tray out too).Might go to LHS and size some up.Id like to find a 4500 or 5000mah with at least a 30c rating.Dont know if a 5000 will fit though.And Im not looking to spend 300 bucks on batteries either.I really appreciate everyones help with my project.

[vasy]

4s go with 10xl.

Hobbywing 120 esc's are nice and they ship fast from hobbyhot. Remember if you spend there $200 (total from all orders) ask them to add you to the discount club for extra 5% off.

4s up to 4000mah seem to fit fine, any more and you are playing with fire.
I'd try this pack that they have in stock: http://www.hobbyking.com/hobbycity/s...idProduct=9511
I lent the guy 3s of this size and it fit fine into a stock tray. (just)
We tried 4500 and had to remove tray and foam from the canopy to make it fit. Not worth the hassle for a few extra seconds of run-time IMHO.

[forescott]

for 4s I run 3600's and 3300's. They are plenty of mah. Remember the 9 or 10 xl on 4s can still be a hot setup if you run it for too long. Dont expect to run the ekos for 30 minutes straight. Start out with short runs. Check your temps. You will probably only get 10 minutes max without bringing it in to cool down. Thats just how it goes with fast electric.

[vasy]

for 4s I run 3600's and 3300's. They are plenty of mah. Remember the 9 or 10 xl on 4s can still be a hot setup if you run it for too long. Dont expect to run the ekos for 30 minutes straight. Start out with short runs. Check your temps. You will probably only get 10 minutes max without bringing it in to cool down. Thats just how it goes with fast electric.

What he said :)
But don't expect 10 minutes, on two 4500 we only get 6 minutes runtime.
So with 4000 you can have save 4.5 to 5.5 depending how trigger happy you are :)

[FighterCat57]

4s 4k 30c packs are the biggest I fit in the EKOS. My 4s 5k packs do not fit.

[LarrysDrifter]

4s 4k 30c packs are the biggest I fit in the EKOS. My 4s 5k packs do not fit.

Thats exactly what I ordered last night-4s 4000mah 30c from HobbyKing.Dont expectem anytime soon.Guess Ill run it on my 3s packs for the time being.(As soon as all my parts come in).I also took the battery tray out a while back and am going to lay down some velcro.

[FighterCat57]

Thats exactly what I ordered last night-4s 4000mah 30c from HobbyKing.Dont expectem anytime soon.Guess Ill run it on my 3s packs for the time being.(As soon as all my parts come in).I also took the battery tray out a while back and am going to lay down some velcro.

That might give you enough room for the 5k packs. It will certainly help with controlling your COG.

[LarrysDrifter]

That might give you enough room for the 5k packs. It will certainly help with controlling your COG.

How do you measure for center of gravity?Never did it.

[FighterCat57]

How do you measure for center of gravity?Never did it.

Pull out the EKOS manual, there's a page on it. Basically measure the bottom most rear of the boat towards the center balance point. Like measuring one side of the teeter totter. Think 8 3/4 give or take on the EKOS.

There's people that can explain it much better than me.

[LarrysDrifter]

Pull out the EKOS manual, there's a page on it. Basically measure the bottom most rear of the boat towards the center balance point. Like measuring one side of the teeter totter. Think 8 3/4 give or take on the EKOS.

There's people that can explain it much better than me.

Ok,thanks.I shoulda thought of that.Have to knock the dust off my manual.Havent looked at it in months.Wonder how long itll take for my batts to get here from HobbyKing?Im getting ancy to get all my parts and tear into it.I was originally gonna sell it all stock to a guy and got it cleaned up and went to set it up for him to test run it and the speedos were dead.All outta nowhere.Ran fine when I put it up.O well, I think Ill have alot more fun with it now.Thanks to everyones help that is.

[FighterCat57]

Ok,thanks.I shoulda thought of that.Have to knock the dust off my manual.Havent looked at it in months.Wonder how long itll take for my batts to get here from HobbyKing?Im getting ancy to get all my parts and tear into it.I was originally gonna sell it all stock to a guy and got it cleaned up and went to set it up for him to test run it and the speedos were dead.All outta nowhere.Ran fine when I put it up.O well, I think Ill have alot more fun with it now.Thanks to everyones help that is.

My guess on those is 2-3 weeks. They are using Singapore post and Swiss post to get around the Hong Kong airport restriction on lithium polymer batteries.

I just got two of my orders from last month last week. At least we know it will get here. Some countries you really have to wonder if the package will make it or not.

[forescott]

I have always gotten my orders to ca in about 10 days.

[FighterCat57]

I have always gotten my orders to ca in about 10 days.

Yeah, they've been pretty good until this past month. Usually within 14 days, but they've had some hurdles to overcome recently..

[forescott]

I got an e-mail from them about a month ago about improved shipping to the u.s.?? Go figure! I think they are worth the wait anyway.

[VIKOS]

I'm willing to bet 4s 9xl 32mm prop = 51-52 MPH.

Should sound really cool at high RPM too! I'm running 2700kv 540's on 4s w/32mm props. Really neat sound and some cavitation which seems to help keep the heat down by reducing the load. Only pulling 53 amps peak. I don't hole shot it, just run it up to speed.

Should be a good setup!

Umm if cavitation is anything like in the refinery business which I'm in... thats not good for a pump,can't see that being good for a motor. Thats when you have a low flow being pumped which would indicate very low cooling on the motors. I kinda want to stick with the 36mm so I'm thinking the 10xl on those would be like 32mm on a 9xl motor..higher RPM with torque. Cooling would have to be right though in this case.

[forescott]

A little cavitation is ok when planing. Some times getting the stinger adjusted correctly for maximum speed requires slight posotive adjustment, which can cause cavitation when planning. You just need to use a little finesse on the throttle. All of the offshore race cats with surface drives cavitate when planing.

[VIKOS]

Well ran the boat today..I cansay I missed running this lil demon..tested it on plastic props gona swap out to aluminum tomorrow for a morning run when its nice and glassy..she did a barrel roll in the water but stayed up right and kept going lol gottah love how well centered the hull is on this thing.