Burst rate of motors

[sprintkat]

If a motor has a continuous wattage rate of 2000 and a burst rate of 3500, will this motor run at the burst rate for
the entire race. or is it like a battery that can only burst for 10seconds before it bursts into flames.

then if i have a 5000 mah 40c discharge battery with a 60c burst, is that much burst needed before the batteries burst into flames.
what it comes down to it, can i run just a 5000 mah 40c discharge battery without a burst rate
this is the leopard 4082 im thinking about buying to use in a 29" sprintcat hull

[lohring]

Motors are damaged by heat. That's a function of current, not voltage. Motors can be run at much more than their ratings depending on the quality of their insulation. As an example, the UL-1 motor is rated at a maximum of 80 amps. We see over 100 amps frequently on P spec boats. The motors often last more than one race season before they fail. For non competition running, I would stick to the manufacturer's rating. A 40C current from a 5000 mah battery is 200 amps. 60C is 300 amps. You need a serious speed control to be able to exceed that, even for a short time.

Lohring Miller

[JIM MARCUM]

A Leopard 4082 2000KV on 4S2P (two 4 cell 14.8V batts in parallel) will get you 29,600 RPM. You may want to look at Leopard 3674 2200 (32,560 RPM) and 2650KV (39,220 RPM).http://www.leopardhobby.com/product/...ionID=01020203. I've ran them in my Miss GEICO & Apparition with great performance. For LIPO batts, I recommend Turnigy Nano Tec 5000mAh 65-130C. ESC, the new Turnigy 180Amp with extra capacitors gives you a great bang for the buck and can easily handle a 4-6S LIPO setup. Should easily get mid 60 MPH out of your Sprintcat.

Many ways to skin your cat's power requirements. This is one. JIM

[Fluid]

If the heat is 45 seconds long, the motor may last. Here is an example - my P Sport Hydro with 1521 motor (1750W continuous/3500W surge) will run a mile heat with warmup lap pulling an average of 2800 watts without problems - the motor has lasted two racing seasons. But, it is getting pretty warm at the end of the heat in summer weather, around 145*F. A Neu can handle that temperature just fine, lesser motors perhaps not. That isn't the contimuous rating - nor the burst rating - but in between. YMMV.




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[JIM MARCUM]

Jay, should get my first full runs with a Leopard 3674 3270KV 4S2P in my Apparition, and a Leopard 3660 4650KV 2S2P this week. Both are SAW builds, so they will get a bit hot. Will take temps and speeds and let you know if they fry or not. Geeze, I hope you have underestimated Leopards survivability. If I can get the speed I need & last 45 seconds thats OK with me. Each SAW pass only lasts 10+ seconds full throttle. Plus, at $80 each I can afford a couple of spares.

If the 3674 3270KV 4S2P survives, the lower KV models should work out OK for SprintKat. I respect your opinions Jay, but I've yet to fry any of my Leopards. JIM

[martin]

Jim what esc will you be using with the 3674-3270kv on 4s, i was looking @ some of the 3674 motors to run SAW with. With poss 2200kv on 6s or 3270kv on 4s. I know the 3270kv is quite a high amp motor which is why i was also looking at the 2200kv on 6s to get the amps lower. Martin.

[Rumdog]

What voltage and what motor kv are you planning on?

[DINO7]

i have them -leo 3674 3270kv- in my H&M intruder twin with swordfish 200Amp.3s for sport running you can run all day.4s for SAW im running 2s+2s in each motor 6000mah nano and im using all the capacity until the lvc...esc and motors come out in reasonable temperature...not very hot but very warm.but that is acceptable for 48k rpms turning motors.the only thing is that i changed the bearings with some koyo japan bearings-true 60k bearings..
here some testing videos.
3s

http://www.youtube.com/watch?v=i-lFjx0mDwc&feature=youtu.be

4s

http://www.youtube.com/watch?v=XGuyCPvQka4&feature=youtu.be

[GTRhino24]

Sick backflips man. Looks pretty strong.

[Fluid]

...Geeze, I hope you have underestimated Leopards survivability. If I can get the speed I need & last 45 seconds thats OK with me. Each SAW pass only lasts 10+ seconds full throttle...

Jim, this thread is about oval racing, not SAW passes. Of course it all depends on the amp draw and the time needed for heat buildup. FWIW my 4S record runs at 82 mph were right at the surge rating for the motor of 3500 watts. There is plenty more there - but not for oval racing.



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[Make-a-Wake]

i have them -leo 3674 3270kv- in my H&M intruder twin with swordfish 200Amp.3s for sport running you can run all day.4s for SAW im running 2s+2s in each motor 6000mah nano and im using all the capacity until the lvc...esc and motors come out in reasonable temperature...not very hot but very warm.but that is acceptable for 48k rpms turning motors.the only thing is that i changed the bearings with some koyo japan bearings-true 60k bearings..
here some testing videos.
3s

http://www.youtube.com/watch?v=i-lFjx0mDwc&feature=youtu.be

4s
http://www.youtube.com/watch?v=XGuyC...ature=youtu.be

You sure like running 10 pound missles right at your kneecaps.....................

[Punisher 67]

Just chiming in - At work can't watch youtube vids here - My browswer is to old .

[JIM MARCUM]

Jay, I realize that my friend. Thats why I suggested the 3674 2200KV Leopard for Sprintkat as a slightly higher revving motor than the 4082 2000KV. It should make a good oval/offshore boat running in the low 30K RPM range.

Martin, I will probably use a T180 with an extra bank of 6 Rubycon ZLH 35V 1000 uF caps. Also have some Nichicon HE 35V 2200 uF due in & will use my Data Logger to see how they compare. JIM

[Steven Vaccaro]

Here is my take. DON'T listen to burst ratings. Most of those numbers are HIGHLY inflated.

[Fluid]

Steven has a valid point, most of the Chinese motors seem to have inflated ratings. I can attest that the Neu ratings are spot on, as are at least some of the Castle numbers. But any motor can go induction furnace.....



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