Matt_M

I'll just cut to the chase. Is it possible to convert an RC18b to a 540 size motor? I know it would be insane, but the idea of doing it just bugs me, although it would be tough I suppose.

Needrcspeed

Yes it is possible. There is a member on one18th.com who has done this, although it looks like crap and is constantly breaking parts. Personally, I think it is a complete waste of time and money for what you gain in the end. You can build up an RC18 with a brushless motor, esc and li-poly packs and reach speeds that will spank one that has been modified to fit a 540 motor.

The opinion of one...

Matt_M

Really...

Well I'll admit, I don't know jack about the brushless scene at this moment, besides hearing Mamba everywhere. I'm a born again RC'er from about 8 years ago when brushless was quite new. So I'm trying to re-learn what's out again quick enough to keep up with my addiction to buy the stuff. The moral is don't ever take a break from this hobby, as what you miss will come back and bite you!

Any suggestions on maximum potential motor/batt setups for these 380 buggies I should be looking at?

Thanks.

Lilredmachine

I never get this... Surely, if one can be modified to take a 540, then it can take a 540 can brushless motor? All the folks that say 'for the cost/work involved you may as well as use a 380 bl system', well, that's not the point is it? Anyone can stick a mamba 8000 pack in an rc18t, but a mamba max 7700 combo? Now you're talking.

Hacker Da-Cracker

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Unles you put a 540 size brushless GTB 3.5 and a lipo. then you could woop the mini mamba lol. just my opion, there is also thing on ebay to convert a mini quake to a 540 size. the anything is that your gonna need a bigger battery.

Needrcspeed

When it is modified to take a 540 motor, it completely throws the car off balance, it requires cutting a lot of the chassis away, a different pinion gear, the suspenion is not designed to hold the extra weight, the car does not steer well at all, etc....If you decide to do such a conversion, please post pics of your progress for all of us to see. Maybe your ideas will exceed those of others that have already tried...and wished they had not.

I am 110% in favor of trying new ideas and modifying cars that push the limits of the original design...however there is a point that you lose far more than you will gain from such an extreme mod. The amount of money and time spent on converting a 1/18 scale car to a 540 motor would be a loss compared to hopping up a 1/10 scale car that is already designed to handle this type of motor.

As for the brushless set up that is good for the 1/18 scale cars...I have been very fond of the Mamba 6800. I have a couple of these and the 5400 in addition to a Dynamite C4 - 9200kv and a 7800kv motor from Cheap Battery Packs. I am happy with all of them.

Silentbob343

overpower the car. Heck you can overpower a 1/18 with a long can BL motor, let alone a 540.

damaged123

Man just go brushless. I only got a stock batt pack for rc18t with mamba 25 and C4 8000 kv and i have a pretty damn big increase in power over the stock motor. If i had a stronger battery on this thing it would easily double in speed and power and it already goes over 30 easy. You dont need anything other than better motors and batteries to reach infinite power with these tiny things wheels. go brushless now dont bother with the bigger can

Matt_M

Is the Mamba 8000 pretty much the top of the pack for speed on 3-cell Lipo?

What sort of speeds are actually possible with these? I have seen the Youtube videos w/ the 8000 and they are incredible...look like about 60mph.

I want to get the best Lipo packs out for output amperage. Any suggestions on what I need to look for as far as voltage/MAH? If I can sacrifice a little runtime for a little speed in any way, that wouldn't dissapoint me as I will buy more batts. So I assume the higher the voltage the better, unless the ESC has a limit before it fries.

damaged123

im sure pretty much any 3 cell lipo with any 8000 kv or higher motor will get you around 60 if you can keep the car down. The combo i have with the c4 8000 and mamba esc was only 120 and im sure its just as good ( i heard it actually has more torque) and i doubt youll ever need anything faster than this with 3s

Lilredmachine

Dynamite make a supposed 9200kv motor.

Overpowering the car is the whole point of this escapade. I figure if you are going for overpowering, you may aswell go for overkill on the overpowering.

Hell, you can overpower the rc18t with a cobalt 14t brushed motor.

nitro _ burner

i dont know anything about brushless except there realy good. can somone explain to me how they work?

Matt_M

I can tell you the basics of how they work. It is the opposite concept from a brushed motor.

In a brushed motor, you have the armature in the center which spins, with the coils on it (turns of wire), and it is surrounded by the magnets glued to the can. The electricity must somehow get to the coils to produce magnetism, so the commutator on the shaft makes contact with the brushes. This is the downfall of the design; friction exists on the commutator to make good connection with the brushes. This is where most of the maintanence comes from.

In a brushless motor, the design is reversed. The coils are attached to the motor can, while the magnets are what spin in the center. Since the magnets require no energy, a commutator is no longer needed, and it can rely simply on ball bearings with much less friction and no brushes to mess with. By design, it is virtually maintence free and more consistent, as well as more efficient obviously.

Back on topic, I plan on buying the 9200kv C4 since it is the hottest I can find. Though I'll admit, I caught myself searching the web last night for a 10,000kv motor which exists. My luck couldn't find one.

Here is another question since I have never delt with Lipo batts and will be buying some. Looks like the max I've seen used for 1:18 is a 3-cell. For higher speed and burst amperage, is it possible to use a 14v 4-cell batt? Or will MAH rating effect speed over voltage rating?

I always thought that MAH is capacity, and voltage is the actual rate it discharges that energy. So given two 7.4v batts, one 1000mah and one 1800mah, do they both make the same power but the 1800mah runs longer? Or does the 1800mah run the same time while making much more power?

I appreciate the help guys.

-Inverted-

Mamba is not the top of the line by ANY means, just affordable.
There are much better systems.

Needrcspeed

Here is very short video clip of one of my RC18's that I ran with the Dynamite C4-9200kv motor, Mamba ESC and a 3 cell 1320mah li-poly pack...

http://youtube.com/watch?v=FYWGLzSnOpE

Gives you an idea of what you can expect from a substantial upgrade that is designed to fit in the car.

Matt_M

Like Lehner?

I know them well as they make the fastest motors for outrigger boats. I don't know which size range from them would fit the 1:18 scale vehicles, though.

Matt_M

62mph...that's fast. I have a feeling 70mph+ isn't too far away in the future if it isn't already being done.

Is there anyway someone could verify my questioning above of MAH vs voltage?

Thanks.

stiltman

If you use a 4 cell lipo you better be sure that your esc and motor are rated to handle it or you'll fry it all. The esc and motor setups that I'm familiar with only go to 3 cells. As far as mah ratings are concerned and increase in mah will mean longer run times, and the ability to maintain the nominal voltage at higher current draws. Also check the "C" rating of the pack. the higher the C rating the faster the pack can discharge its charge (more current). If your C rating multipllied by your mah rating aren't enough for the rest of your setup then your voltage will drop under high load, and your output power will be less than it could be. As soon as you have a pack that can keep up with the esc and motor, more mah just gives you longer run times.