How many watts?

[FighterCat57]

I'm trying to figure out how many watt's I'll need to get a 41" mono hull in the 35-40mph range.

I'm building up this Vanquish as a salt water sport boat. So basically I want to get as much run time as I can and use as little power as necessary.

I don't want to waste a 1717 on this hull, or any other expensive components, so I'm thinking about putting a 4082/1000kv on 8s2p and using an 80HV ESC.

The 80HV will serve up well with a 4082, both rated at about 2600 watts on 8s.

I figure an m545 might be about the limits of that setup on 8s. I've got a bunch of old 4k 20c 4s packs that aren't doing much and I could care to lose. Mind you this boat is going into the atlantic ocean so I have to accept losing it completely before putting it in the water.

Any real world knowledge for this before I go frying things?

Besides putting a real motor and ESC in it.

[Make-a-Wake]

I say 2200-2500 watts................

[keithbradley]

Ben I would run that motor on 6s with a larger prop. Something like an x452. Definitely favor diameter over pitch.
I think I'm understanding you correctly, that you will be running this boat in rough water? I ran my DF 40 in Lake Huron (decent sized waves) on 6s with a 1020kv motor and it was more speed than I could use.
The larger prop will stay "hooked" a lot better in rougher conditions and when you are on and off the throttle. A 45mm prop is small to start with for that boat. Add to that rough water and you are going to waste a lot of energy in cavitation.

[Make-a-Wake]

Ben I would run that motor on 6s with a larger prop. Something like an x452. Definitely favor diameter over pitch.
I think I'm understanding you correctly, that you will be running this boat in rough water? I ran my DF 40 in Lake Huron (decent sized waves) on 6s with a 1020kv motor and it was more speed than I could use.
The larger prop will stay "hooked" a lot better in rougher conditions and when you are on and off the throttle. A 45mm prop is small to start with for that boat. Add to that rough water and you are going to waste a lot of energy in cavitation.