Joysway prop change

[Beijing-Boater]

Hello everyone! I am a newbie to the RC boat world and very much look forward to your advice and comments. I have just purchased a brand new Joysway Wildcat (4 pole 4074, two 3S 4000mAh 30C Li-Po's) and looking for advice to an optimum prop change that will help with speed and stability...thanks!

[tlandauer]

Where can you run in Beijing?? Summer Palace is great in warm weather but I doubt you will be allowed to do it. May be BeiHai Park, never been there, I am always curious for good lakes around major cities. I was in Beijing in last August and all I can think was I wanted to run my boat in those beautiful lakes. Went to HangZhou and saw West Lake :buttrock::drool:
I think we need to know a bit more about your set up, i.e., what kv is your motor, are you running 6s or 3s2p, etc.
What size is your boat? I am sure other people might know this particular boat, but it is not familiar here.

[forescott]

What comes on it stock??

[Beijing-Boater]

Thanks for the replies! There are MANY lakes in Beijing (outside city center) The one I run in is Roma Lake in Shunyi, near the airport. I am running two 11.1v Lipo 3s (does this mean 6s?) size is 37in, 120amp 4 pole, 1900kv, stock prop is P1.4XD44mm two blade.

Beautiful large lake...

https://foursquare.com/v/roma-lake/4b6813a0f964a52042662be3

[tlandauer]

Thanks for the pictures, I must say I don't know this lake. Looks great!
If you connect your two 3s ( 11.1v) batteries in series, yes, then you are running 6s, unless your connection is parallel, then your voltage remains the same as 11.1 but you gain run time since capacity is doubled.
Let's say you are running 6s (22.2v), then you are spinning more than 42,000 rpm ( 22.2v x1900kv= 42,180 rpm) , this is quite a hot set up, not really recommanded for sport boating. The motor and ESC is under alot of stress. You prop is "large enough " at 44mm for this set up.
You will be better off using 4s, either 2x2s or a single 4s, another way is to have two 4s connected in parallel ( doubling the capacity = longer run time) . This means your total voltage should be 14.8 v. It is possible to run 5s ( 18.5v), but then you have to have different batteries , perhaps too much to do for now. I personally think to run 6s on a 1900kv motor with a 44mm prop is risky, especially if this is your first boat and you just want to have a good time.
Let's hear what other people have to say.
Cheers and happy boating!

[Beijing-Boater]

Thanks for all of the info! I know Joysway makes a pretty good boat, Ive especially heard a lot of good things about the X-Blaze. This step-up (stock) for my boat, as I mentioned is recommended from JW, lipo's included. I would sure hope they wouldn't sell a package that ran too hot. Also new mods for 2013 include a 120A rather than 100 and the prop upgrade I also mentioned. Here is their link, take a look...

http://joysway-hobby.com/Product_show.asp?proid=500

[tlandauer]

Nice boat! I am not familiar with this particular model, it seems JW has a different market in North America, they sell smaller and more entry level products.
When I said "hot" I meant at that RPM, it is more than sport boating's goal, and SAW ( straight-aways) can reach 50,000+ rpm. So it is not that rare to have 40,000+rpm as some people just like to run their boat that way, but SAW runnings are short bursts of sprints and therefore set ups are different. Your hull is more than a meter long and to run 6s on a 1900kv motor with a 120A ESC is asking a lot. Also you will have very short run time , if it were my boat, I would double up the battery capacity and run parallel set up. Either 4s2p or 5s2p, but there will be expense associated with new batteries.
What connector does JW equip the boat with? The amp draw is high in boats and you need to have at least 5.5mm bullet plugs all around. ( motor-esc, esc-batteries, etc.) http://www.offshoreelectrics.com/proddetail.php?prod=ose-55bullet
Having said all that, 1st question wasn't asked, have you run your boat? How was temperature after 2 minutes? ( 1st run don't run more than that, in fact under 2minutes) How did you like the speed?
To answer your question regarding props: most important thing is to have your metal prop BALANCED/ SHARPENED.
Something for you to consider: Up grade your ESC to at least a
Seaking 180AESC:http://www.offshoreelectrics.com/proddetail.php?prod=ker-seaking-180
Cheers!

[Beijing-Boater]

Thanks sir! I do understand your concern as well. I am running 5.5 or 5.8mm? (male end measures with a caliper 5.8) bullet plugs all around. Also, I just bought some new lipo's with this connector...
http://detail.tmall.com/item.htm?spm=a220o.1000855.0.0.oFJHZI&id=16681796531&acm=03067.1003.1.898&uuid=oYCjfMA8&abtest=_AB-LR67-PR67&scm=1003.1.03067.ITEM_16681796531_898&pos=5
Is there an adapter I can use, so I can use these lipo's?
Thanks!

[tlandauer]

These are "Deans" Connector. There really is no good adapter, I buy my lipo batteries and either cut them or de-solder them and change to 5.5mm bullet connectors. The "Deans" are good for RC cars or truck up to a point, since GEARED set ups require less amp draw. With Fast Electric Boats, you and your equipment will be much happier with bullet connectors.
I suppose you can make your own adapter, but the internal resistance increases as there are more connections, if I were in your position, I will change them to bullet connectors.

[Beijing-Boater]

Sorry for the delay, I'm just back from Shanghai. I want to thank you for all your knowledge and advice, it is greatly appreciated! Take care and happy boating sir :thumbup: