Which prop for my setup?

[Ctonez]

Wait a minute...2 4S packs in parallel?!?
this adds a bunch of weight, I usually use 2 2S packs in series.
more weight and longer runtime will likely fry that Ammo or your ESC or both with anything larger than 40mm...and even then, it's too much for that high KV motor.

Running 2 4S packs in parallel (10,000mah) isn't going to get you twice the runtime of 2 2S packs in series (5000mah). The extra weight and load on the motor will use up more capacity at a higher rate, not to mention stress the system and slow the boat.
2 2S packs is really the best way to go with this boat IME.
I'm betting noone who gave you prop advice is running 2 4S packs...that means their info is not going to help your boat with it's 8S onboard.

[planezero]

Id estimate two 4S packs weigh about the same as two normal 6cell NiMh packs which the stock boat was designed for.
Shouldnt think this to be a problem ?
It'll certainly go faster with 2x 2S if you have that option (less hull in the water).

Berry

[Ctonez]

the ammo runs hotter than the stock unit. The Ammo didn't like 12 cell weight in my boat, and certainly wouldn't push a 642 or bigger without getting really hot...especially after 9000mah. I wouldn't run a 640 on that setup either.

I'll just say that I don't think your Ammo will last long with the weight and the prop options being considered.
If it were me and I already bought the batteries, I'd run both packs in the boat, but only plug one in...run it, temp it, check capacity after 2 mins. Let it all cool...plug the other pack in if pleased with temps etc. and go again.

[ibyte]

the ammo runs hotter than the stock unit. The Ammo didn't like 12 cell weight in my boat, and certainly wouldn't push a 642 or bigger without getting really hot...especially after 9000mah. I wouldn't run a 640 on that setup either.

I'll just say that I don't think your Ammo will last long with the weight and the prop options being considered.
If it were me and I already bought the batteries, I'd run both packs in the boat, but only plug one in...run it, temp it, check capacity after 2 mins. Let it all cool...plug the other pack in if pleased with temps etc. and go again.

I beg to differ there Ctonez? i have had excellent results with the Ammo 2300,octura 642 and lipos the difference is i dont use nimh packs so that maybe why you have heat issues i dont. The motor gets hot but not to hot 123 on the motor and 121 on the esc after 5 minute runs and i check right away. But the way you are suggesting to run is good and im sure that would be the correct way to try things out thats just my thought.

[hex-dj]

Steven or anyone who understands this ...Is it true that, in Mono racing detonguing is not so necesary ,while it will be necesary when running,say a catamaran or a rigger?

[egneg]

Not true!

It all depends on the prop and your set up.

[hex-dj]

Thanks egneg. I read that somewhere else and was curious to know. I thought it was bs at first ,but wasn t so sure. I learned how to do the detonguing and so far I ve detongued 4 propellers, 440/3, 42x55,X640,x640.

[egneg]

Good for you! Props are an art form (by this I mean it is a matter of trial and error as every setup is a bit different). There are degrees of detongueing depending on the original prop and application. Just as some folks like a satin finish while others prefer one that is highly polished. The next step is cupping which has a much steeper learning curve and is easier for seasoned racers ... maybe one day enough recorded data will be available where this information can be quantified.

[hex-dj]

Good for you! Props are an art form (by this I mean it is a matter of trial and error as every setup is a bit different). There are degrees of detongueing depending on the original prop and application. Just as some folks like a satin finish while others prefer one that is highly polished. The next step is cupping which has a much steeper learning curve and is easier for seasoned racers ... maybe one day enough recorded data will be available where this information can be quantified.

Yep! True.

[hex-dj]

with what you wrote egneg.