Need some Clarification on these Motor Specs

[RCprince]

Can some explain to me contrary to popular belief why ammo motors of the same size can produce more power(wattage) than a 6 pole lower kv motor...My LHS told me also that Ammo over exaggerate their specs. case and point they have a 28-56-3200 motor putting out 666 watts...thats 90% of 1 horse power



Most likely Proboat Brushless BJ Stock Motor:

HiMaxx HB 3630-1500
Dia mm: 36
Length mm: 53
Kv (RPM/volt):1606
Efficiency % 87
Max Amps: 55
Wattage:600
Poles: 6
Max RPM: 40,000

Ammo In-Runner Brushless Motor

36-50-2300
Dia mm: 36
Length mm: 50
Kv (RPM/volt): 2300
Efficiency % up to 89
Max Amps: 100
Wattage: 1110
Surge Wattage: 1850
Poles: 2


36-50-3300
Dia mm: 36
Length mm: 50
Kv (RPM/volt): 3300
Efficiency % up to 89
Max Amps: 100
Wattage: 832
Surge Wattage: 1850
Poles: 2

[Steven Vaccaro]

Specs are just specs unless the same person runs them and posts the info.
Thats why all us racers test on our own. The fastest guys usually test the most and tune the best.

[RCprince]

Thanks Steve the reason I asked is because I'm a mad scientist...I hooked up 7s to an Ammo 36X50 3300kv mtr running a 637 prop....the boat ran fast mtr just warm to the touch

[Steven Vaccaro]

thats 70k rpm.... What am I missing? If that was the case you would be in the 130mph range.

[RCprince]

Thats why I guess specs like you said are just Specs....probably at that high voltage which is 2s above spec max voltage efficiency goes down dramatically.....at 34 bucks i wanted to see if the mtr would blow up...but it held up....

[RCprince]

I may have been in the high 50's early 60's before I ran out of lake space....I was also on the verge of going airborne. before I test these mtr I use your conversion chart to calculate speed, and I get the same thing...but as I lower the mtr efficiency the speed becomes more realistic

[Steven Vaccaro]

But as you decrease efficiency you increase amps and heat.

KV RPM specs from most companies should be real close. The specs in question are efficiency, watts and max amps. They can make the numbers look how ever they like.

I have to warn people reading this thread. I would in no way recommend running this setup. It WILL end up blowing something up.

You want to be a mad scientist? Buy or borrow a eagle tree with the brushless sensor and post the results with a video of the run. Than we can get an idea of whats going on in there.

[SJFE]

I'd pay good money to see THAT video.

[RCprince]

I over did it when I ran that same set up with a x645, It melted the solder on one of mine connectors and killed my 110 Hv...But with the 637 I ran it on 2 full recharges of the lipo....remember these are runs that are about 300 to 400 + feet oneway, then we run the otherway....But in noway or fashion m I trying to deceive anyone...just reporting what I experience...our 1,000 dollar sony Camera won't keep it's recording on disc...it keeps corrupting the disc and keeps trying to repair the data to no avail.

[domwilson]

These are decent. I have a couple of them.

http://www.aiptek.com/

[Steven Vaccaro]

I understand your not trying to deceive anyone. Just letting the young-ins understand this isn't the setup to run.

[SJFE]

I wana be clear also...all I wana see it your boat blow off the water ...Nuffin but love for ya man

[Flying Scotsman]

I understand your not trying to deceive anyone. Just letting the young-ins understand this isn't the setup to run.

A very sensible positition. Way too hot a set up and people with less experience will follow that set up, because they want speed without knowing the consequences that a high rpm small motor coupled with high voltage and large props will result in.

Douggie

[blakybob]

I'd like to chime in on the Eagle Tree suggestion. I'd love to see some rpm and amp charts. That's definitely a "mad scientist" setup IMO.

Blake

[domwilson]

Somebody was doing some deep digging...2 1/2 years later....