HPR C5009 upgrade - goal 105 mph

Hi there,

Im upgrading my HPR C5009 for the third time. Here´s a short presentation of the two earlier setups:

2 x leopard 4082 2000kv
2 x seaking 180a V3
Props: Octura X 2/446 (cut)
Max speed: 129,6 kph (80,52 mph)

2 x leopard 4082 X2 2200kv
2 x seaking 180a V3
Props: Octura X 2/446 (cut)
Max speed: 140,9 kph (87,55 mph)
Same setup and ABC 1814 17 45; 155 kph (96,31 mph)

When use of ABC the setup is reaching its limit. ESCs cuts (thermal cut?). LVC is deactivated. The lipos are in SAW world record category, so they deliever enough power; SLS Quantom 65C and Roaring Top 80C.

Further plan of upgrade:

The seaking 180A has impressed me. But now Im beginning to experience that it could not handle bigger props. My next step was to go for ABC 1915, but ended up on 1817 - which is smaller, but has a pitch of 1.7.

Based on these new props, Im going for 2 x swordfish 240A datalog. I considered twin swordfish X 300A, but I think 240s should keep up. Will be interesting to test.

That beeing said. I have had a lot of fly offs after using ABC. So I will lower the drives a bit, and also have some more weight in front than earlier.

The setup with seaking 180As:

Attachment 159789

The setup with Swordfish 240A (need to order new ones, this on is already in use in another boat):

Attachment 159790

ABC props (Dashboata):

Attachment 159791

The new motors:

Attachment 159792

I would say that your ESC’s is most certainly your issue. Also try and get rid of some of that wire length. Take it to a minimum possible(you’d be surprised what a few hundred rpm would do). You are at a point here where it is all fine tuning. I have a few tips on that but let’s go one at a time to see increases. What size connectors are you running ?
Another thing I would suggest is to pick a prop diameter and keep it. This will save some trim adjustmen. Ie: get 1915’s and trim to 46mm.

Shawn

Great progress...you will need props with max. 47mm and 3,5" nom pitch to get in the 100's mph club.
Gill

Quote:

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Originally Posted by srislash

I would say that your ESC’s is most certainly your issue. Also try and get rid of some of that wire length. Take it to a minimum possible(you’d be surprised what a few hundred rpm would do). You are at a point here where it is all fine tuning. I have a few tips on that but let’s go one at a time to see increases. What size connectors are you running ?
Another thing I would suggest is to pick a prop diameter and keep it. This will save some trim adjustmen. Ie: get 1915’s and trim to 46mm.

Shawn

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Thanks for reply. I use 6mm bullet motor/esc and 8mm bullet from ESC to the batteries.

Quote:

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Originally Posted by grsboats

Great progress...you will need props with max. 47mm and 3,5" nom pitch to get in the 100's club.
Gill

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Thanks, Gill.

I will be very suprised If I dont reach 100 with 1817. But only one way to find out Also need to check heat and ampdraw before going bigger on props. Also - Can the motors keep up/run bigger props

My riggers with Tppower 4050 motors on 6s can keep with no issues props with 47mm like the V947 but I had to upgrade my esc from the SF 240 to the SF 300 as my peak currents are around 330A.As you said be patient and check your temps and ampsdraw to go bigger!
Gill

The ABC's definitely are a lower lift design than your previous Octura props, so lowering your drives makes sense.

I did about 106mph with a dual 1815 ABC props, TP 4050 2050kv, SF200, on 6s 5000mah... with a crappy china hull like the Shocker. I'd imagine the HPR hull would be even more efficient at SAW passes than what I was running. So you shuld have no issues getting over 100mph with the hardware you have. Perhaps it might be worth upgrading your motors to the new TP line of motors, with KV around 2300kv and 4050 or 4060 cans. I'm sure they are even more efficient now and can handle a bit more RPM than before.

Use motor oil or Bar oil in your flex cables and experiment with CoG -- position your lipos back a bit until you start flipping at high speed and keeping the drives at neutral ...

Hi,

Som updates:

ABC 1817: I was shocked after 3 runs. 360 amps!!! and 70 celsius/158F
Octura x 2/446 (cut): 280 amps, almost same heat as above.

Timing is set to low, even though the 2200kvs are Y wind - based on 4-5 other motors Ive had, low timing has always proven less heat on my setups, wether D or Y wind.

Next step:

Test the octuras (most safe) on medium timing and try to adjust CG. I had the weight much more in front in my test.

Doesnt seem to run to wet though?

Attachment 160105

Have moved the escs a bit more back:

Attachment 160106

At least go with new line of TP motors

Quote:

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Originally Posted by grsboats

Great progress...you will need props with max. 47mm and 3,5" nom pitch to get in the 100's mph club.
Gill

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At what RPM? Any recommendations? I'm building a very similar size hull and the only way to get this much pitch at this RPM is by cutting diameter and even the 1917-17 and 2016-17 don't quite get you there. Cupping?

Quote:

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Originally Posted by srislash

Another thing I would suggest is to pick a prop diameter and keep it. This will save some trim adjustmen. Ie: get 1915’s and trim to 46mm.

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Yes, I cannot understand why a prop change recommendation to increase speed always tends to include an increase in diameter.

What is reasonable slip percentage on a setup like this? Doing the math on some of these speed results yields 50,000+ RPM from a KV/Voltage setup not even capable of that RPM no-load. Are these results with props modified to increase pitch beyond manufacturer specs?

What is a expected/reasonable/ideal actual RPM vs. no load RPM? I read .85 somewhere here... It seems this value would be helpful in determining proper motor loading and prop selection to supplement current logging.

Great thread thanks Amir please keep us updated!

The datalogging of my last tests showed 42.000rpms turning a V947 (stock) and 386 amps ......yes amps go to the roof easily if overpropped I'm about to test an ABC 1918 (3,6 pitch but 45mm) but I'm talking about a rigger.Gill

And what is no-load max RPM?

aprox 59,700 rpm on my set up.