Keep getting told to run a 57mm prop. What does that relate to with an octura prop number. I have a box of all sizes from my nitro days.
so it what voltage are you running? 4s sure you can do that with a 1730kv. above 4s thats a giant heck no on a 57mm 1.4 pitch. as you spin faster you use more wattage. either by higher KV or higher voltage gets you more RPM. your motor can only handle so much wattage. realistically 3000w continuous. basically wattage = speed. your hulls drag coefficient causes it to use, lets say 3000w @ 58mph.
now you can get the 3kw/58mph target by spinning slow with a larger prop, or fast with a smaller prop. If you try to spin fast with a big prop you overheat everything, your batteries wont last.
amp draw:
4s -14v (under load) 3000w / 14v = 214A
6s - 21v (under load) 3000w / 21v = 142A
8s - 28v (under load) 3000w / 28v = 107A
as you can see the higher voltage you run, the lower the amp draw, the lower the amp draw the longer batteries last. You are looking at a 6s motor. Its too large for 4s because LIPO cant push 214A. Lipos are good for 125A-175A at race distances. depending on the quality. its too high of KV for 8s because you would have to run way too small of a prop to achieve your hypothetical 58mph. which is realistic for your hull by the way.
essentially if you run 8s you need a KV around 850-950. you do need to run 8s in that boat. with 2 4s packs in series you can run 6500mah packs. Look at a TP 4070 780kv $129 on their website. Run like a 2317-17-45 ABC prop. Or 2417 (2.4 inches, 1.7 pitch) to get into the 60's.
