Ok guys I'm a believer now!
 

I have been one of the biggest supporters of the Novak hv maxx brushless systems, even when others have bashed it. Well i believe you guys now, I'm not bashing Novak, as i still believe its a great beginner system or even for those who are not sure if they want to go brushless, Because its a familar in an unknown world (everybody knows Novak), Its why i started with it.
I just got my mamba/ 9XL/ 12 cells setup going and am just as impressed with it as i was with the Novak hv. it doesn't do wheelies yet (stock revo tire and lowest setting on the rods), but it will spin the tries for a few feet and goes about 35 right now with a 17/66 32pitch setup. I am currently running it on the bec in the esc (good for 12 cells according to castle). No good info on temps yet, but will tomorrow.
As I said this is not a Novak bash but, i got my feet wet in HV unsensored and now loving it.
Thank you all for the answers to Questions and all the testing you did to make my experience better. Cheers to all (we need a toasting smiley on here)

Now that you've done that, get yourself a UBEC and put 14 cells on that 9XL! The MM ESC will handle it I think you'll be pleased with the power. :027:

Actually, you should use a UBEC anyway because the BEC on the MM is dissipating at least 2-5 watts of power even on 12 cells. That will free the heatsink to cool only the FETs and should help temps.

I'm going to run it hard tomorrow and see if its really needed. Tonight test was just to see if it was setup right, havent even played with the programming, want to see what it will do in default settings.

Honestly at 12 cells its just about fast enough, i'm not a speed freak, just a racer that wanted a better and more efficient setup than the Novak.

Fair enough. If you're happy that's all that matters! :)

Yeah Thanks for the advise, I will go to a ubec or a external pack if necessary. I opinion on power is, "If you can't use, it why have it", so for racing this will be good, May try 14 cells to see but will be down the road.

We will check back in about a month or two and you will probably be asking about 14 cells or Lipo. Its the progression that most everyone goes through. Too much is never enough, what you think is too much now won't be enough later. Ask me how I know.:018: I'm running a Wanderer 7XL, Quark 125, Orion 4800 Lipo's, Gmaxx chassis with UE-bulks,towers and drive/axle shafts, Jammin Bigbore shocks, and Proline arms just to name a few. About six months ago I had a stock Emax with a Novak HV setup. :018:

I got an mgm 16024 and 7XL and 12XL motors, if i need more. I wanted a better racing combo for racing. We run 5 minute heats and the track has a few areas that too much power is a bad thing. On 12 cells its almost perfect, just need a little more speed to keep up in the straights, I'll kill them in the corners

12 cells has got a nice weight. Not a bad choice for racing.. If the other start running too fast, you can always ad a few extra cells..

I glad you have experenced other power.

Good to hear Larry! Good luck with racing, you'l really enjoy it!

larry, try not to break so much stuff..will ya....

Did you have the 4.5 or the 6.5?

He has the 6.5.

Yeah i had the 6.5, or more specificaly the 4400 with a sintered rotor. I got to run it today and i'm impressed, with 12 cells it was running somewhere in the 30's (no gps sorry), but it seemed like it would lose signal momentarily every so often, so i think you were right about needing an external source. All in all its a great combo, good speed and i think i have some gearing options because it seems to pull good and temps seem stable. will try next with a battery pack to see if it is the problem. I have heard of people having trouble with interference with UBEC's, If you had trouble, How did you fix it? If i got to i can use my nitro pack for a whilre before deciding on what to get

by mounting it away from any power wires and away from where the antenna is.....is one of the ways

I think you should ask newe...since he is the ubec glitch king....he might have some answers...lol

hey you guys! So is the mamba esc and 9xl going to outrun the hv-maxx? and what gearing do guys recommend? My trucks an emaxx carbon fiber chassis with custom alluminum arms and rpm knuckles with bow tie tires running on 14.4 nimh

On 12 cells, the mamba/ 9XL is a great combo. it will need an external power source so need a battery pack or ubec and remove the middle wire in plug to reciever. I'm running 17/66 32 pitch gearing and think i got room to gear up, but will not know till i know the problem with the signal.

so ur having problems with the combo? or with your reciever? what do u mean ill need a battery pack or ubec? I'm sorry u'll have to excuse me cause i really dont know anything about brushless systems.

I think the BEC is overloading, it will lose signal every once in a while. The way i was told if it overloads it will cut-off and restart, so i think thats whats happening. I'm running a bigger than recomended motor and running the bec at its limit, so i expected it to happen. I will get back to you tomorrow or tuesday at the latest and tell you if the reciever pack helps.

No problem with inexperience, I was there a few months ago, did a lot of reading before i took the plunge, but till you get you're feet wet you don't know as much as you think

The BEC in just about every ESC I can think of is just a linear voltage regulator. This means there can be a lot of heat dissipated on the regulator, and gets worse the more cells you use and the more servos you use. If you are running anything more than 2s (or 6-8 cells) I would use a BEC. Some people use the ESC BEC up to 12 cells, but I am a bit anal about such things. The excess heat from the regulator will heat up the heatsink for no reason.

A UBEC is a digital device, meaning it uses pulse-width modulation to regulate the main battery voltage down to 5v or 6v for the servos. These are MUCH more efficient and hardly heat up at all.

If you are REALLY interested, here 's an example:

Linear BEC (found in ESCs):
dissipated_power = ( main_batt_voltage - 6v ) * servo_current

Let's say you are running 12 cells and are running a servo that draws an average of 1A at 6v. The heat the ESC heatsink has to dissipate is; ((12cells * 1.2v) - 6v ) * 1A = 8.4 watts. That is quite a bit believe it or not. This equates to about 41% efficiency (output wattage / input wattage). Also, 1A will be drawn from the main batteries just for the servo (even though it is only using 6v), which reduces runtime. At 16 cells with this same 1A servo, efficiency would be down to 31% and heat up more (13.2 watts).

A digital UBEC (and they almost always are) runs between 80%-90% efficiency. So, if the servo draws 1A at 6v, the UBEC only dissipates about 1W or less of power (at 85% efficiency) and draws only ~.4A from the main batteries. And with more cells, the UBEC will draw less current from the batteries yet still be just as efficient or more.

This example is a little off because a servo won't draw 1A all the time, but you get the point.

Thanks BrianG, that helps me a lot

No problem. I actually thought I overdid it at first.

Na, it explains a lot about why it would cut-off. I tryed it because Castle said it would, but i'm running a bigger motor and it may have an impact

As Shawn described it to me, what happens when the mamba's bec is overloaded is that it will shut off the bec to let it cool and then turn right back on, and it will do this 20x per second if neccesary.

So what you see is a radio glitch as you are getting, because the rx is losing power for a fraction of a second.

This would be very obvious if you run a Spektrum because they take about two seconds to power up if power is lost.

I had some glitching with (both) my becs, used a Rx pack and it was smooth as silk. Had a hard time finding a good place to put the BEC. My try it again later.

I actually had way more glitching w/ my FM than AM. ???

FM frequencies might be closer to the UBEC switching frequency to cause interferece. AM frequency is generally lower and further away from the UBEC frequency so the band filters on the AM radio are more effective. Just a theory.

hey thanks so much for the explanation BrianG. Kinda hard to swallow all that. So ur saying with my setup of the mm and 9XL ill be needing a UBEC to be safe? But I think all ill be using will be a 7.2v 2s 4000mah batt's Anyway wats the diff with the Feigao 540C 9XL Brushless Motors & a Feigao/Nemesis/Wanderer "9XL" Brushless Motor? And i should get a gearing of 17/66 32 pitch ?

Was that with the 27 fm or 75 fm?

The Am was 27, and the Fm was 75.

The Am was pretty good, I would just get an occational glitch at long range, but it was the "slam on the brake" variety, so I switched it out.

The Fm is a XR3i, I wanted it so I can adjust servo trims and to turn down the brake some (the MM/XL would front flip easy) but it was undrivable. It had a range of ~30ft, and even ran away on me a time or two. :031: Put in the Rx pack and all is fine.

Ok. I ran the ubec on a futuba 75 with great luck. I wonder if some radios
are closer to the frequency of the ubec. Kind of like the esc are more
to interference with some.

It's possible some radios have a narrower band filter and sharper cutoff slope than others. This would allow less "noise" to enter the circuits.

I ran it today with a recieverpack and the middle wire removed from the plug, It runs fine now. Run a whole pack without a problem, so I'll be looking at UBEC's next time i go to the rc plane shop. So, please call out what you have run and the results you have with them, so i can see what they have and what works (would buy from Mike, but got to support the locals first:027: ).

Ok, next thing. Running it today it runs good, but needs a little more speed. My temps for one pack run are:
Motor; 119*f
esc; 159*f
batteries; 129*f
No fans used and temp outside was 76*, can I gear up without trouble? I'll add a fan, as soon as i get a chance from radio shack, Any recommendations on voltage to look at for fans? The acceleration is strong and i don't think the motor is even trying.
Thanks once again and sorry for all the questions

First, I would get the ubec from Mike, I have had the best performacne from those. Fans-go with 5v fans, they push real good air.

The plane shop near me has Koolpower UBEC's, If they don't have that one I'll get it from mike

I like to run 12V fans right off the battery leads. I soldered in a rx/servo connector right on the mamba's main wire tabs outside the case, with about 1" wire leads. So I can plug in a fan or ubec right at the esc.

Fans vary in output and you don't know till you try one. Some are weak and some kick butt, both 12V and 5V... imo one is not "better" than the other. It just depends on the particular fan you try.

I think you can gear up no problem... you don't really know until you experiment to find where the breaking point is.

A fan on the mamba will help a lot if temps jump with a gear change.

160's is not bad at all.... CC says the temps were 220+ when they got them to thermal, and it won't damage the esc either.

I got an 18 right now and can get up to a 20 from Mike, Can Mike make 32 pitch gears bigger than a 20?

I believe so.

I run it today as well, found out the slipper was too loose and prevented the wheelies from happening, now it won't keep the front wheels down for a good run without real careful throttle control. This is with a 5 cell battery pack in the front, its going to be a real handful when i go UBEC. thanks for the help guys.
The track i go to has closed up but the owner is going to set up another track in a different area and let the business side of it die. I'm going to wait till the track is done before i decide on gearing

Could you post some pics or videos im thinking of doing the same setup with 14 cells!