Decided to get more run time from my boats

[Raydee]

After running my Brushless 1/8th scale truck and getting almost 20 min of run time I started thinking that running my boat at 60mph its fun but for only 1.5 min at a time. I don't race boats and never will so I think I would be better off showing them down a bit and increasing my run time. I would really like to get 3 or 4 min run time without major heat. I am going to change the motor in my 30" Whiplash hull, right now I am running a 1515 1Y on 4s and I am thinking a 1515 1.5y might be a way better option without making the boat to slow. Does anyone run this motor in a 4s hydro?

[NativePaul]

Have you tried just propping down? In Europe we race our 4s hydro2s for 5 minutes on a 560gramm 5000ish pack, and most use higher KV than is generally run in the states 2700 being quite common, we just run a smaller props to get the runtime, the revs keep the speed up. As the 1515/1y is only 2200kv you may need to switch to a smaller X6 if you are running an X4 now to keep the pitch speed up.

[Raydee]

I tried to run smaller props and it just seems like they heat the motor and cells up more. I think a 30" boat with a prop that is to small just struggles, kind of like a car driving in first gear all the time.

[red6]

You could always try keeping the motor and prop and go with 3s batts with higher mah.

[Darin Jordan]

You could always try keeping the motor and prop and go with 3s batts with higher mah.

That's a really good thought to consider...

[Raydee]

It is MUCH cheaper for me to buy one new motor instead of multiple new Lipo's. Nothing I own runs on 3s so its 4s or bust for me.

[NativePaul]

That's strange, I could hypothesise that the 1515 was operating under its max efficiency range and heating up more propped down, but I cant explain why the cells got hotter.

[Raydee]

I think its because with the smaller props my heavy hull has a hard time getting up out of the water and it runs wet. With a larger prop the hull jumps up oit of the water and actually runs cooler BUT its harder to keep the hull from becoming airborn. I am def planning on moving to the 1500KV motor on 4s before the end of this season.