...was thinking of a 3 to 4 foot cat maybe longer just wondering what size motor and esc ill need to get it up to 50 to 60
I can give a few examples, a lot depends on how you want to run the boat - sport running, oval racing, SAW racing, run time expected, etc. The run times I show below are for full throttle racing, less severe running would extend those times.
34" Aeromarine Sprint Cat:
Neu 1527/1250 Kv motor, Castle ICE240 controller, 6S2P/10,000 mAh, x455 prop race setup
55-60 mph running for 2-3 minutes, could run longer if slower
Scorpion 4025/1100 motor, Castle ICE240 ESC, 6S1P/5000 mAh, x455 prop sport setup
45-50 mph running for 2-3 minutes, could double that if running 2P
41" Stryker catamaran:
Lehner 3060/10 motor, Schulze 40-160 controller, 10S1P/6600 mAh, x465 prop race setup
60-65 mph, 2-3 minutes racing, more with 2P
Scorpion 4035/850 motor, Schulze controller, 10S1P/6600 mAh, x457 prop sport setup
50 mph for 2-3 minutes, longer with 2P
These are boats I run so I know they work, no "theory". You can spend more or less, but remember you can have speed, reliability or low cost -
choose any two.
.