the basis of my name (genesis)

[blowNover]

ok so lets see how many people i upset possibly makeing my first post in the wrong forum. if i have please just let me know and i will do my best to move it. ok so i am rebuilding a hk genesis. the hull is all but done so thats not where i am going. but i know i am doing this all wrong buying all the parts before finishing the research. but here is goes ive got a leopard 4092 1730kv 3d, turnigy 180amp third gen with cap bank speed control, running on 2x gens ace 3s 5000mah 40c. so with the motor choice what would yall say is the best timing i know it needs to be low due to the motor wind being a d wind so the plan was one of my three lowest settings 0*, 3.75*, and 7.50* and with that timing what would be the best prop for allout speed, best for greatest reliablity and speed, and just the most reliable. lets see if we can make this a 55 to 70 mph boat.

[MAMBA2200]

:popcorn2:

[grsboats]

3,75 have worked for me and you can try a X447/2 or 447/3 to start........there is a lot of power in this motor for this boat and this is a cat good for straights so take care with fast turns.Gill

[Fluid]

Welcome Genestein. You are posting in the correct forum. Your motor choice is a bit extreme, I hope you don't smoke your components too soon. THe motor shoudl use either 0 or 3.75* timing advance, it should make no real difference. Prop choice will make a big difference. Your rpm on the water will be around 34,000 so prop accordingly. An m445 should get you above 55 if you get the boat trimmed out well.

A few things to pay attention to:

- Keep the wires from the ESC to the packs as short as practical. Ideally the total length of wire from the packs to the ESC board is 7". That is seldom achieveable so just aim for as short as practical.

- Keep the run time low at first. Use a watch and run for one minute, then bring the boat in to check the temperatures (you do have a temp gauge?). If temps are okay, run for one more minute and bring it in to check. Keep doing this until you are certain the setup is safe. I know this seems a pain, but it is less of a pain than burning up an ESC.

- Make sure that the hull is a watertight as possible. When you flip over - and you will flip over - you want the hatch taped well. Water and ESCs in particular don't mix well. Guess which one wins?

- If your ESC does get wet, don't run it! Dry it off completely, or you risk a burn down.

- Listen to Gill, he makes some good points although I'd be careful with prop choice at first.




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[iamandrew]

Lol, your going to need a fair bit of re enforcing of the hull if you crash at 70Mph thats for sure.
its pretty hard to get the genesis going in a straight line when its single drive going over 50mph
having said that, its probably the best value hull you can get, and really easy to upgrade.
make sure you are using bullet connectors on your batteries as well, as Deans and other types can melt together :S

[blowNover]

great thanks gill thanks fluid
the prop i have to start with at this point im thinking i may need to hold off on running till i get a new one. from the best that rich at funrcboats and i could come up with is it looks like x645 that had been shaved down to around 43 mm and has not been detongued. but has been rebalanced and sharpened.
i will start with the 0* timing but i have read that running timing to low may cause heat issues as well.
i do think i may be able to shorten my battery leads a little so i will.
i dont have a lazer temp but its on my list of needed tools.
as far as water tight i actually lined where the hatch sits in with thin weather striping so when taped down it creats a very good seal. (already flipped more then a few times before bbqing the stock motor)
one last thing i didnt mention was that i installed two octura stream line pickups as far aft on the hull as possible. one dedicated to the esc the other dedicated to the water jacket.

[blowNover]

lol no i havent reinforced the hull frankly im not really sure how to. but yes i do have the bullets thanks andrew

[blowNover]

so would the prop i have be to much or not enough i guess what im asking is will it be to risky?

[TristanJones]

I'd go ahead and run the prop you have just make sure you get the temp gun first (I use one from HK was about 15bux US I think, maybe less and is very accurate) and check your temps every minute till your sure it can handle a pack at full noise without smoking it. IM keen to see how you go as Im soon to be upgrading parts on mine, though Im not going as big as you have in motor and i think will run 4s.
Tristan.

[blowNover]

as far as batteries i have the gens ace 3s as mentioned before but in leu of the task at hand could i get the same speeds out of a couple 2s with more reliability? if so
recommendations would help lol. also would using packs that can only produce about 150 amps help save the esc and motor or will the motor just ask for more then the
packs can deliver and destroy them?

[TristanJones]

Going by what I'm experiencing right now I would say it will draw what it needs and cause issues if batteries aren't up to supplying the requirements. I run 2x 2s2p 4000mah 40-50c and temps are at 50-55c after a solid 5mins with the stock motor and 1.4x40 metal prop.

[blowNover]

So you're running 14.8 volts but I'm not completely sure about 2s2p batteries what are the constant and burst amps? And how much top end will I loose going from 22.2 volts down to 14.8 if any?

[TristanJones]

Yeah Im running 14.8v with a p1.4x40mm prop to get 70kmh on 4s (and 79kmh (49mph) on 5s). However batteries are very hot (50-55deg-c) after 5mins of running. 2s2p means a 2s battery pack made of 2cells each in parallel.
My packs are 4000mah 40-50c turnigy (so I highly doubt the c rating is as high as they say).
4000mah = 4ah
4ah x 40 = 160ah so my batteries are capable of delivering 160ah in theory. However! I do not believe this to be the case, OR it's just not enough power, I need to fit an AMP meter and see what its pulling.
For my ESC to see the temps it is I believe it is seeing over 120a constant draw yet under the 240a its max burst rating is.

As the motors are KV rated (rpm per volt) you will loose prop speed and therefore top end or outright speed if you do not select the correct KV rated motor to keep prop speed up, you can change the prop to try and help if going from 6s to 4s but I wouldn't expect to see huge gains in top speed without increasing RPM.
Increasing RPM by increasing the KV rating on the motor, yet staying at the same voltage will inherently increase AMP draw on your batteries and ESC, this will in turn increase heat, I would recommend running at least a T180 ESC with a 2000-2200kv motor for a 4s setup and a decent size prop (45mm or so).
For 6s you choose a lower KV motor as I believe the desired RPM by most with these boats is, from memory, around the 36'000-40'000mark, I hope someone will correct me or back me up there, I'd like to know for sure.

Hope that helps, Tristan.

[blowNover]

Ok but I thought the 2p means that the amperage is double so a 2s2p would be 240 amp not 160 and have a much greater max burst. And yes I have that speed control.

[blowNover]

Any help on re-enforcing the hull would be awesome as well. Thanks again everyone.

[TristanJones]

I'll second that!