12020 or 9920 for E-hyper 7? - RC-Monster Forums

sleebus.jones · **12020 or 9920 for E-hyper 7? -** 10.18.2007, 08:27 AM

I'm gonna get one of these, just not sure exactly which one to get. I don't want to get the 12020 if it's just excess capacity that I don't need. I've got a fiegao 10L on it now, and I intend to run it with 4S - 5S.

I'm pretty sure the 9920 will fill the bill. However, I don't know exactly how "fragile" they are. Do I really need the extra current handling capacity of the 12020 to keep from letting the smoke out?

Also, bypassing the internal BEC with these is pretty much a given, isn't it?

Thanks for any help,
Sleeb

jokerjustin · 10.18.2007, 09:57 AM

if you have the cash get the one with the higher capacity. it will not hurt and you can have a little extra confidence that ur esc will be ok

sleebus.jones · 10.18.2007, 10:52 AM

The cash is not the issue. Spending cash I don't need to is.

lincpimp · 10.18.2007, 11:18 AM

A 10l on 4s is not that high draw of a system. I have my 10l on 4s in a LS10 with a mm running it and it works fine. My truck is reasonably light, what truck are you running this in? I am sure that the 9920 will work fine, especially on 5s. The 10l may be spinning a little fast on 5s, a 9xl would be a better chice, or maybe a 12l. Kv rating somewhere near 2000 is more suited to 5s as it keeps motor rpm near 35k.

othello · 10.18.2007, 11:21 AM

Difficult to say. BK ESCs weak spot ist partial load handling. They do heat up quite easely. If you drive a lot at partial load then the bigger ESC should be better suited. Otherwise i do not see a prob using a BK9920 in a buggy with a 10L motor.

lincpimp · 10.18.2007, 11:35 AM

Sorry can't read, you have a hyper7. I would go with a 12l, or a 9xl motor. The buggys get heavy with the batteries etc. The 9920 should work fine.

10.18.2007, 11:39 AM

If you are running this in a buggy, I'd just go with a Mamba Max and keep it to 4S, or are those still hard to get?

4S is plenty in a buggy.

othello · 10.18.2007, 11:46 AM

BK ESC do not have a proper lipo cutoff. You will need an external LVC. Rumors in Europe are new BK ESC will be released. But no further information than that.

sleebus.jones · 11:50 AM

Quote:

Originally Posted by lincpimp

A 10l on 4s is not that high draw of a system. I have my 10l on 4s in a LS10 with a mm running it and it works fine. My truck is reasonably light, what truck are you running this in? I am sure that the 9920 will work fine, especially on 5s. The 10l may be spinning a little fast on 5s, a 9xl would be a better chice, or maybe a 12l. Kv rating somewhere near 2000 is more suited to 5s as it keeps motor rpm near 35k.

It's a Hyper 7, so not too heavy. Yeah, it's obvious now that I picked it for 4S running now, isn't it? Hehe, oh well. I agree, you are spot on with using a 12L or 9XL. The "Mr. Overkill" in me says "do the 9XL" but that may be an awful lot of torque for a 1/8th buggy! I can also get to 4S real easy by buying another Apogee 2S 3800 pack. I've been running it with NiMH and I'm "ok" with the performance, but after throwing the eagletree on there, it's obvious I'm getting a LOT of voltage drop. I think 4S on that would feel pretty peppy from what I'm experiencing now.

Quote:

Originally Posted by othello

Difficult to say. BK ESCs weak spot ist partial load handling. They do heat up quite easely. If you drive a lot at partial load then the bigger ESC should be better suited. Otherwise i do not see a prob using a BK9920 in a buggy with a 10L motor.

Well, this will be more of a basher/toy than a racer. It'll prolly be spending most of its time full on, coasting or full brake, heh. Although if I get on the track, i'll be feathering the throttle more, I'm sure.

Quote:

Originally Posted by othello

BK ESC do not have a proper lipo cutoff. You will need an external LVC.

Ew. Forgot about that. I know about the LOA, anyone have any other favorites?

Good input!!!

Anyone else?

Sleeb

lincpimp · 10.18.2007, 01:21 PM

4s on the 10l is a good setup, you will have to gear it lower than the 9xl. If you have a choice the xl motors are better at handling the heat than the l motors. I have a 7xl in a light mt, lighter than a buggy, and it does not get hot and is geared for 55mph! I run it on 4s thru a MM and it is fine so far. Try the 10l and 4s out and let us know. I personally do not like the 9920 as much as the MM but the 9920 can handle 6s so it depeds on your future battery choices.

sleebus.jones · 10.18.2007, 01:49 PM

Quote:

Originally Posted by lincpimp

I personally do not like the 9920 as much as the MM but the 9920 can handle 6s so it depeds on your future battery choices.

Yeah, and that's exactly my problem....I'd rather go higher voltage/lower Kv than the other way around. The 4S upper limit of the MM is what has held me back there. The higher voltage makes such a difference in the amp load put on the packs, so I could get away with cheaper (trueRC) packs because I might not need a 20C pack to to the job if I end up running 6S.

Yeah. 11XL on 6S. POW, right in the diffs!

Sleeb

sleebus.jones · 10.19.2007, 09:35 AM

Well, the die is cast. 9920 and Castle BEC on the way. I'll run it on cells for now and see how she goes.