What ESC do I need?

[GoFastNow]

I have a SAW hydro, weight is 17 lbs, using a TP 5680 (1070kv) on 12s turning 2 (1817) props. I am currently using a Swordfish X300 esc, and it seems to be ok so far, but I have no idea if this is ok, or is it about to fail? Any guidance or recommendations greatly appreciated. Its going from zero to 90 mph in 3 seconds now.

[koen]

A 300amp esc is good, swordfish or ZTW are good esc .i use a ztw to full satisfaction

[TRUCKPULL]

The Swordfish X300 esc has data logging. You should use it.

LJ

[GoFastNow]

Yes it has logging. Last I looked, it maxed out at 490 amps, and 17,500 watts. Thats why I asked for help, because I dont know what to make of these numbers.

[TRUCKPULL]

Yes it has logging. Last I looked, it maxed out at 490 amps, and 17,500 watts. Thats why I asked for help, because I dont know what to make of these numbers.

With numbers like that, I would prop down, or reduce your pitch.

LJ

[larryrose11]

Yes it has logging. Last I looked, it maxed out at 490 amps, and 17,500 watts. Thats why I asked for help, because I dont know what to make of these numbers.

you need a smaller prop, or a larger motor.

[TRUCKPULL]

You could try 10S instead of 12S, with the 12S you are way over 50,000RPM
10S would put you down around 42,000 to 46,000RPM
Use your 1817 props, keep your runs down to two passes, and check your heat and your Log.
Let us know your results.

LJ

[GoFastNow]

Do you think it will go faster on 10s? This is a Drag boat, I only make a single run, then go pick up the boat. Run time is about three seconds, so not getting hot, motor or ESC. A few years ago when I started this project, I had a goal of around 100 mph, I am getting close, but not sure if I am ok, or is it about to burn up the ESC.

[TRUCKPULL]

One run of 3sec. should be fine. just keep a eye on your logs.
They will tell you if there are mechanical woes starting to show up.

LJ

[larryrose11]

Are you concerned about top speed, or track time to cover XXX feet like a real drag boat?
Do you have a actual course set up with timers and all that? That would be impressive.

Going to 10S will lower the RPM but will allow you to use a larger prop with more bite for a better launch.

[GoFastNow]

The boat is 36", I try to do both, I want it to leave hard, like a real TFH, but I want some decent speed out of it. I am going about 220', zero to full throttle and 90mph in about 3 seconds. So far, I am pretty much the only one driving this boat, so I have nothing to compare to, or get knowledge from. I use this handy little device for ET, MPH, and distance.143071490_3964601003591179_5788248291570344957_o.jpg20201001_140250.jpg

[larryrose11]

Cool.
To get a consistent performance, you may want to play with the Startup settings in the ESC, and just gun it off the line (like toggle between Slow and Standard). Like some sort of Launch Control in performance EV's
The idea being the perhaps the Slow setting with a bigger prop will prevent cavitation off the line and yield a better ET/ longer peak acceleration. Slow startup will also (likely) have a current limiting effect, limiting tur current ramp up at start
More consistent performance will also allow better tuning of the setup.

[EddieM41]

Where do you come up with 50,000+. The OSE speed chart says only 42,757...still very high rpm. Just curious?

[TRUCKPULL]

Where do you come up with 50,000+. The OSE speed chart says only 42,757...still very high rpm. Just curious?

12S - with a load drop from 4.2 V per cell to 3.7 Volts per cell = 44.4Volts
motor is 1170 KV
1170 X 44.4 = 51,948 RPM

LG