Amp draw Q Hydro

[ezhitz]

I wanted to know what kind I amp draws can you expect to see from a Q Hydro. I do understand I it will depend on prop selection weight boat running wet these kind of factures. The boat is a sport 40 whiplash motor Neu 1530 .75y prop tried aluminum 2 blade 4814 48mm batteries revolectrix 60c 4400 mah 2p rtr weight just under 12lbs. Had a turnigy 240 esc in it until it stopped working so I tried my 220amp swordfish with data logging and thought the amps would be lower then my 4s p hydro. What seem to lower the amps was running an older set of turnigy 4000mah 30c.
The boat needs more set up as it seems to hop a little https://youtu.be/l1gXqNqWVIE
Revolectrix 4400mah 60cRevolectrix 4400mah.jpg

Turnigy 4000mah 30cTurnigy 4000mah.jpg

[Fluid]

Like any boat, it depends on how hard you load it. Mine runs a Neu 1527/1Y on 6S1P/6500 and an ABC 2116/17* prop. Average logged amp draw on the oval is around 175 with peaks near 230 amps. Mine weighs 10.5 lbs and hits high 60s, fast enough to be competitive.

There is a general misconception that high voltage setups pull higher amps. This simply isn't so - or at least doesn't have to be. Higher voltage is simply more efficient than higher amps. Power comes from voltage x amps x efficiency, I find that my Q and T boats pull lower amps than my 2S/4S boats to be competitive.

I never understood the desire by many for 300+ amp controller in 10S setups, but they only need 240 amp controllers for 4S boats. Too many boaters seem to feel that brute power is the only way to get more speed and performance, but that isn't necessarily so. Efficiency in the power unit, the driveline, the prop and the boat setup is what does it. It is a combination of all these, plus a few more. Why do you think that Joerg held the T Hydro SAW record for so many years by running round cells against LiPos? His 'secret' was in the sentences above.


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[CraigP]

Fluid is hitting the nail right on the head! Higher voltage should result in lower current, given the load on the motor has parity between the lower and higher voltage setups. If you run a boat a 36,000rpm with a given prop then that is a given load. If you raise the voltage and put in a motor with the kv chosen so that the prop is still spinning 36,000rpm with that same prop, then you will see a drop in current. If the LV setup was let's say, 4s and you went to 8s (keep the example easy) you would more than HALF your current, because higher current setups are less efficient, just as a Jay said. I'm running 8s on an 11lb, 34" hydro and hitting mid 60's with WOT turns, and datalogging 90amps average with 115a spikes. I got a 150a ESC, and I haven't blown an ESC or puffed a battery. The efficiency gain is really quite remarkable!

[ray schrauwen]

What hull are you running?

[CraigP]

A good running hull in Q Sport, which is a 6s class, is running 170-220a. Most people I have seen and read about are using 280-300a ESC's. And a lot of folks in Q Sport burn ESC's, so work your setup from the slow side up to faster in small steps. I would data log it, but that's just my preference...

[ezhitz]

Ray was the question to me or fluid ? I am running a blazer sport 40

[RaceMechaniX]

Jay, you might have to eat your words. Joerg had to custom build his latest controllers to push more amperage. He says the controller is good for about a 1000A. By the way, he ran 298kph today in Munich. More on that later.

All in good fun,
Tyler

[ray schrauwen]

Cool, so am I. Mine needs the driveline changed. I started with 1/4" but I don't like it. Going down to 3/16". Pain in the rump job but maybe I'll get on it tonight.

Are you going to the Apple Butter Festival on the 30th? I'm trying to get some boats ready. Hopefully this nice weather holds up.

Ray was the question to me or fluid ? I am running a blazer sport 40

[ray schrauwen]

No kidding! Wow.
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That controller is something wild.

Jay, you might have to eat your words. Joerg had to custom build his latest controllers to push more amperage. He says the controller is good for about a 1000A. By the way, he ran 298kph today in Munich. More on that later.

All in good fun,
Tyler

I tried a SF200 8S esc with a TP4070 custom 1250kv and it just choked badly. The SF240 worked o.k. but like others say, you have to work things out or you get heat issues like me. The motor they made me is a monster however it's an amp hog. The batteries never had an issue but the motor and esc's would be nuclear.

[CraigP]

That's interesting... What you're describing sounds like a switching/timing issue. If the current is switched at the wrong time in the coil, the coil can induce voltage at the time of the switching. This produces a large loss on the switches (ESC) and the motor. The fact the batteries are not real hot also lends validity to this, since the current is isolated to a loop between the ESC and the motor...

Perhaps different timing or in some cases, capacitors placed in parallel across each coil, can shift the current/voltage change to something that's more efficient. I've had to do this in large servo motors running under high acceleration PID loops..

[ray schrauwen]

Well, I've been out of the game a while so I'll try a few things on the 30th. Go back to Auto timing and see what that does.

Anyway... something was not right.

[Fluid]

Jay, you might have to eat your words. Joerg had to custom build his latest controllers to push more amperage. He says the controller is good for about a 1000A....

Thanks Tyler, you have made my point very well (but apparently didn’t read my post very well). Joerg’s 140 mph record stood for many years, you tried many times to beat it with boats putting out at least three times the power (wattage) yet after years of trying you only managed to raise the record about three miles per hour.

I thought I was pretty clear, it isn’t just about raw power, it’s about a total system which works. Joerg’s total system was a lot more efficient than yours, that’s all.


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[RaceMechaniX]

Very true Jay, just having a little fun in light of the news I heard from Joerg. His boat needs 1/3 the power mine does for the same speed. Now he has optimized everything about his power system now that the batteries are 10X more powerful than the round cells. Hopefully he will post some pictures of his new battery which is pretty impressive.
Brian was able to run almost the same speed I did with 1/2 of the power I had in his P hydro at 140mph.

I will say though SAW and heat racing are two different worlds. I have wached David Hall run 100mph in a 2-lap boat, but the boat was so on the edge one bad input resulted in somersaults.
A good heat racing boat will be light, but stable and this is a balancing act for the power needed. My Q heat racing boat is around 8 lbs with the 1717 motor and a 6000mAh battery. Current draw is around 180A continuous and 240A peak. It will run 8 laps and no more. It runs a little wet, but its planted and stable and can run in almost any water condition.

Tyler

[ezhitz]

A little more testing today was surprised to see the results.
Was a little cooler today at about 68 degrees water was flat slight breeze.
Running a M545 with little more ear removed I ran the boat for 1 mill lap 6wide open laps and 1 cool down lap.
results where 69mph motor temp 91 esc 102 batteries had 55% left. I didn't think that would be enough prop for the boat
but until I get it dialed in better I will stick with. The boat still hops in the straight and it seems to carry the left sponson out of the water.
Seven runs today and the speed was between 66-69 mph depending on which packs were run.

[Navherc130]

We're these current results with the swordfish 220?

[CraigP]

I wanted to know what kind I amp draws can you expect to see from a Q Hydro. I do understand I it will depend on prop selection weight boat running wet these kind of factures. The boat is a sport 40 whiplash motor Neu 1530 .75y prop tried aluminum 2 blade 4814 48mm batteries revolectrix 60c 4400 mah 2p rtr weight just under 12lbs. Had a turnigy 240 esc in it until it stopped working so I tried my 220amp swordfish with data logging and thought the amps would be lower then my 4s p hydro. What seem to lower the amps was running an older set of turnigy 4000mah 30c.
The boat needs more set up as it seems to hop a little https://youtu.be/l1gXqNqWVIE
Revolectrix 4400mah 60cRevolectrix 4400mah.jpg

Turnigy 4000mah 30cTurnigy 4000mah.jpg

What's the voltage you're running on the Q Sport? The boat is looking pretty good to me! Got some chop on the water and the hull is handling it very well...

[ezhitz]

Yes they are but its the older SF220 not the newest one.

[ray schrauwen]

Wow. My older sf220 would shut down all the time.

Never got it ready for last weekend. Looks like I have to wait until next year.

When I'm in Vegas I'll check out some of their setups to see if I can get more ideas.

Nice results so far. You might notice less hopping when racing with others when water is rougher, I did.