Originally Posted by
OutlawRC
I have been on 2 and 4 wheels since the 80's but would consider myself a noob with brushless boats.
I've got the 29" Rio EP (owned for maybe 5-6 years) and runs the stock brushed set up. Now I've got the itch to make it a little faster and ordered a way overkill esc (150a).
The reason I ordered one this big is because my LHS said I could stick a car motor in it without issue, and I've got a few laying around, seriously debating on the Viper 4.5r 4500kv.
Sticking with 2s due to lack of room.
So, my question is this...Since I see mostly lower KV and higher torque motors in boats will a higher KV motor work ok in a set up such as this? It's already plumbed to cool the esc and the motor.
My other options that I know I have laying around is a stock 17 turn, a Novak Ballistic 5.5, and sure I have a few others but nothing in the 3700-3800 range which is what I would like to try.
Thoughts on the 4500?
Anyway, during the process of soothing my upgrade itch I went ahead and ordered a 37" Inception and should be here tomorrow. Already got the batteries and everything I need for it I think.
Still thinking about making the Rio brushless.
My experience for select Motor KV is calculate How many cells of battery are using. i.e. 3700kV using 3 Cells, Simply 3700x 11.4 x 80%(Motor Efficiency) = 33733 RPM
Normally, I will use the Range from 32000-45000 RPM depends on what kind of Boat Hull. Like Mono Hull around 25% efficiency will use higher RPM like 45000. and Outrigger have higher efficiency 10% will use 33000. Max. Speed will never higher 50000RPM it cause serious over heat and damage the Bearing.