Heat diff betweeen these setups

[BHChieftain]

Hi,
I'm looking to increase my RPM target for my syncron. I'm currently running a neu 1515 1.5Y 1500KV motor on 4S, with a large prop (on this config it runs stone cold...). Using a hydra 240A ESC (overkill, I know...)

I'd like to get to 32-33K RPM and can either run my existing motor on 6S, or use a 1515 1Y 2200KV on 4S.

Would there be a significant heat difference between these 2 setups? I though I read earlier that it is better to add voltage vs. KV if given the choice.

All things being equal I'd prefer the 4S setup as I would not need additional lipo packs, but I would priortize reliability/runtime over that...

Chief

[westbeach]

I am running a 1515-1.5Y setup on my Cyberstorm running 5S. On 4s you're barely pushing that motor. On 6s, the difference is cut clear. I believe you're right in adding Voltage, everything runs cooler. But someone please confirm this.

[Fluid]

For the same output power the 6S setup will definitely be easier on a HV ESC since it pulls far fewer amps. The motor will see the same watts so it will probably be close to the same temperature since it is neither larger nor more efficient. Run time will be longer too, but heat build up will probably be the limiting factor rather than pack capacity.

But IMO running 6S on a 6S maximum controller is asking for trouble, particularly when we get greedy and keep propping up and up, increasing the amp draw. So if you run 6S and intend to get higher speeds, get a HV controller. You'll be around 30,000 rpm on the water with either setup.

I suspect that you will be happier overall with the 4S setup as you can use your existing packs and controller. The Syncron is not a large boat and 4S is probably more appropriate anyway.



.

[JMSCARD]

I ran a 1515 1.5y on a Hydra lv120 for 2 years on 6s in a Mean Machine 29" hull with no issues... ran a x440 prop.... not saying its super smart but I did and it was reliable.... esc never got crazy warm either... the 1515 1.5y is a much lower amp setup like fluid says... I don't think I would want to run a 1515 1y (4s) much at all on a 120 amp speedy.... but it sounds like you are running a hydra 240 so you won't have any need to upgrade that if you decide to go 1y..:_)

[pda75]

With 6S, the synchon may be too heavy. I would try the 4S set up.

Pierre

[keithbradley]

Have you considered running on 5s? You could do that with your existing motor and just prop it more conservatively (larger prop than 6s though). I think you would be happy with the results. I dont know what prop you are running now but if it comes in cold you may be able to run it on 5s with that prop.

[BHChieftain]

Here's the other consideration-- the syncron has a flood chamber, so there is only room for a 2S pack along side the flood chamber next to the motor. The other pack has to be up towards the nose. So if I run 6S, I need to run 4S in the nose, and 2S towards the back. Or I could try a 5S config with 3S in the nose, and 2S in back. So I think I may end up nose heavy with those configs...

But on either 5S or 6S, I'd need to order 2 more lipos... since I like hyperion lipos, it is actually cheaper to buy a new motor...

I don't suppose anyone has a 1515 1y they would like to trade for my current 1515 1.5Y?

Chief

[BHChieftain]

I've decided to give the 5S setup a go-- might be the happy medium between speed and heat... hopefully the COG should work out.

Chief

[BHChieftain]

Ran with 5S today on x645 prop, still running cool. Video gets pretty choppy towards the back but the first 2 laps give a good sense for the speed.

Balance is ok with the 3S pack in the nose.

http://www.youtube.com/watch?v=I-otch75WMQ

Chief