Nineball

This isn't exactly a "rookie" question, but here goes...

I've read a lot about published specs, why Castle keeps them secret, why most numbers cant be completely trusted, etc. Generally, you overbuild and hope for the best, right?

So what do you do when pushing the specs to their limits?

For example: a TP Power 4050cm (40x83 can) 3200kv rated for 6s. The Tekin RX8 meets the amp draw but says it won't play nice with 6s over 1700kv. Probably not a good match?

How about the same motor with a hobbywing max 6 or max 5? Their specs are listed for 58mm cans, so how concrete are the kv limits for an undersized can?

It seems to me, the only way to not build a bomb would be to go for something boutique like Alien Power Systems. Even then, they don't list motor limits, so picking one to use is about as easy as picking a Castle that won't fry (and they're currently not letting anyone run above 2200kv with a D-wind motor).

I guess, which specs so I need to watch out for, and which ones can you fudge a bit?

GerryH

iTrader: (26)

There are dozens of variables in play and the manufacturers are providing a general guideline of what will and won't work. Also hard to know when a vendor lists Max Amps for a motor, under what circumstances that number came from. I have a 10.5t, standard 3650 sized motor that pulls 220 amps on 2S when doing a dyno pull. But my ESC is fine because that's only a burst.

What are you planning on using that TP motor for? I've only seen it used for speed runs.

Nineball

Drag racing. So I'm only pushing limits for... 3 seconds, tops. In this case, I'm sure there's a lot I can fudge, but I'm not sure what.

One of my local hobby shops bought out Rudis Racing, who makes 1-3s drag cars (basically stretched pan cars) that hit 100mph in 1.1seconds. Those cars are going to have their own classes to run in, but for the open class, they're going to dominate unless someone builds something to compete. Going with a 2.0t on 1s in a 2.5lbs car isn't the only way to go that fast, I want to prove that point. So, I'm looking at 4s-8s TP power motors to shoehorn into something (probably direct drive).

Simply put, I don't know what happens when you push spec limits. Would I just be building something that would explode? Would my esc just beep at me and not want to run with the wrong motor hooked up? My pockets aren't deep enough to experiment that much.

GerryH

iTrader: (26)

Unfortunately, you're exploring the bounds of the electronics in a way they weren't primarily designed for. Not that they won't work, but you're not going to find specs for drag racing. The other problem is, you won't know that you've found the limit until something smokes. The good thing is that it's a pretty short burst of power and current draw goes down as the car accelerates.

The Hobbywing and Tekin have similar burst amps, so I'd say it's a toss up as to which one would be better in this case. I might lean towards the Hobbywing since they are slightly less expensive and if you do burn an ESC up, they have a trade in program to get a new ESC at a discounted price that's much better than retail.