PLEASE HELP ME!! (pick out setup)
 

This is going to be long, and annoying, so sit down, relax, read, and PLEASE help me!!!! :yes:

In feb 08 I decided I was tired of nitro, and BL was what I NEEDED. I set out to buy a Losi Muggy and convert it to a BL beast that would be faster than my nitro buggy that was set up VERY well. At that time, the MMM was coming out, which was supposed to be good. Long story short, I've been through 5 or 6 MMM's, and it's grown old. VERY old; I'm done. They're a great company, with great people, but no matter what I try, or what I do, it just doesn't seem to work for me.

So, I'm going to try the RX8, and if that doesn't work, I'll be having a little garage sale that you're all welcome to attend, though most items will be launched out the garage and on the lawn! But I do wonder all the time if my setup is wrong, even though Castle says it's fine. I can't mess around with the MMM anymore - I've been through 5 or 6; one of my V2's even melted a $130 digital servo, and that's just a nice little loss I had to take. Oh, and I spent the whole season last year with nothing that worked! It's been nearly 14 months since I placed my original order for my MMM, and almost all the time I had a working controller, it was winter and too cold to go outside. Well, summer's here, and I'm NOT letting my $1500+ toy sit the summer out again!!!! Nooooooooooo!

I have:
Muggy (about 12lbs; 4WD 1/8 scale truck)
Tekno Neu 1515 1Y (2200kv)
6S 4800 20C Hyperion (Enerland cells)
MMM
12T pinion (also have an 18; it wants to fly into outer space with this!)
HPI phaltline tires and wheels for street use

I Want to:
make this truck go about 55mph
NEVER BREAK!! EVER!!!!!!!!! (at least not my motor or controller)
stay as cool as possible, even if it's 90+ degress outside - NO THERMALLING!
use the RX8

I only bash, I'll never race. My driving is mostly speed runs in a parking lot, some track use (not racing), and messing around in a park. Oh, and the occasional construction site. I don't recall any of my MMM's making it past a parking lot.

I would like to keep my batteries if I can, as they're expensive, and I doubt I'll get much for them on ebay. Monster Mike says to go down to 5S and a 2000kv motor. Tekin says 6S is ok, and go 2000kv. Castle says 6S and 2200kv. And of course, I remember people on here last year saying go 1700kv, some even lower. If I knew who was right, I wouldn't be making this post right now!

So, I want an RX8, and I plan to sell my Neu motor to get an RX8 combo. What motor should I get, should I drop down to 5S, and what pinion? Please though, only make a recommendation if you really know what you're talking about (I can't deal with this damn thing breaking anymore!!), please keep in mind I want it to stay cool, and I AM aware how silly it is to have a truck this big go this fast. Are you aware how fun it is? :intello:

I do keep an eye on temps; my radio has telemetry. I will also have LOTS of cooling going on, as well as the RX8 fan.

Well, I know that 6s + 2200kV = a very fast motor. That isn't they way to stay cool. It is the way to go fast, though. What would be your gearing (p/s) at 55mph on that setup? Honestly I don't see you having a truck THAT fast that won't ever thermal or run hot unless you go HV.

If you plan to keep the gearing for 55 I would go with a motor that will top out over 40k rpms, and be as long as possible. On 6s that would be about 1800kv-2000kv. The muggy does not have that much gear reduction anyways, so gearing it up for the speed will not be very difficult. I am not too familiar with the big tekin motors, but the truggy length models look like the ones to use. Not sure if your 20c? lipos will hold up. 12 lbs trying to do 55mph will be putting some load. I would use a lipo good for 150amps cont on 6s, so a 5000 30c.

Looking at the tekin motors and the speed calc, I think the 2000kv 4038 t8 motor looks to be the best bet. With 6s motor rpm will be around 45k, and you can use a 14t pinion to get 55mph. Keep in mind that you will not be able to gear much lower than a 12t, which will get you down to 45mph. Not too bad, but that is as low as you can go on 6s. You could swap to 5s and lower motor rpm if you wanted to gear slower.

Will this run cool? I have no idea. The tekin setup is new, so who knows if it is any good? Just throwing that out. I would be interested to see your results, especially with those lipos, as I think you will work them hard.

Heres the speed calc with the setup I proposed.


Differential Ratio: 4.090909090909091
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 46
Pinion Tooth Count: 14
Total Voltage: 22.2
Motor KV: 2000
Tire Diameter (inches): 5.5
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor coil Ω: 0
Spur/Pinion Ratio: 3.29 : 1
Total Ratio: 13.44156 : 1
Tire Circumference (inches): 17.28 inches (438.88 mm)
Total Motor Speed: 44400 RPM
Vehicle Speed: 54.05 mph

If you want that kind of speed with the Muggy... you have got to go high voltage.

12 1/2 lbs is a little heavier than my e-REVO ready to go. If that is your weight ready to run I think your going to need a massive motor to keep things cool on a 90* day trying to hit 55MPH. On the hottest days my 1515 2.5df gets a bit warm with gearing for 40mph on 5s. I'm sure the tekin ESC will be fine but I don't know if their motorwill be enough. Maybe a 1518 or 1521 neu or 80mm medusa would be a better choice. Or you can be a little more reasonable with your speed requirement and gear for 35-45MPH. I honestly think 35 is plenty to have fun with, pushing to or past 40 creates a lot of O shit moments.

The only thing I can see wrong is how hard you drive it and if the gear mesh is too tight. If you are always accelerating 100% and using the brakes constantly I can see where it might cause problems.

Your setup is very similar to Joe Fords setup he has for a Kyosho GT2 for speed runs (100mph+). You can check all the details and videos here. It sounds like you need to let the car cool down. Joe's car probably weighs a little less than yours. maybe 10lbs.

This is his setup:
6s 5300 30C
2200kv Monster Max combo
2 speed transmission

This is what he said:
http://www.rccars.com/forums/attachm...7&d=1241792995

http://www.rccars.com/forums/attachm...0&d=1241792995

http://www.rccars.com/forums/attachm...8&d=1241792995

I would also think a bigger motor for this setup would be optimum. The muggy is heavy and big. Personally I would gear it for 45 and be happy. That is alot of speed for a truck that size for general use. Plus trying to gear it for street runs of 55 then offroading with the same gearing is asking a bit much from any ESC. How many nitro muggies with less than a perfect tune on a top of the line engine can maintain 45+ on and off road?

I like the double servo mount on the IGT. I wonder when Mike will offer that for sale? Maybe make a package with it and the kyosho mount together?

People like to throw numbers out, like 55mph, but usually they have no idea how fast 55mph is for an r/c car. Hell, at 40mph they are outta sight in a few seconds. My friend swore up and down his rustler was hitting 70mph, and when we gps'ed it his fastest run was 44mph.

Gearing a muggy for 55 seems to be the reason you killed so many MMMs, not the MMM.

I believe to get everything you want you'll need to go HV like 12s, or run 2 tekin systems. You just want too much.

I have both of my truggies geared for 34-36mph and one actaully has gone 46mph and it is spot on when I added a 1" ballooning (5.65" truggy tires) in Brian's calculator. If you gear your Muggy for 55mph without adding tire balloning, it will be going a lot faster.

Yes, above 35mph or so tire ballooning does start to affect speeds in a big way.

Just run a 2215, shulze hv speed control on 12s... just gear down a bit and you wont know what heat is....or what money is after you buy all of it..

thanx to all. I think I'm gonna try 2000kv rx8 combo and see what happens. Anyone interested in a tekno neu 1515 1y for sale?

To repeat the already said:

Bigger batts: 20C 4800 (96A) is too small
Bigger motor: 1521 will do the job and stay cool. Muggy is a big truck
Be reasonable on speed. Do you really need 55? 45 is fast already.
Small tires will help

You are prolly pulling 2500W+ peak. That's a ton of power. Overall I would say the setup is a bit underengineered for the task at hand. I wouldn't assume a new esc/motor will fix it if the specs are not being raised. If you really want big reliable speeds, a MGM 160A/8S controller would be needed and a 1521. You could have bought it already w/ all the dead electronics you have now I bet. Else lower expectations

people have mentioned the Neu 1521 a few times, but I don't understand why? I mean, if the 1515 has the power to make the truck fly (if I strapped wings on it), why do i need an even bigger motor?? What is the difference? Does a bigger motor run cooler? If so, why??

I might be - sent you a pm.

Yes a bigger motor will run cooler. Would you put a 2.0L 4cyl in a F-350 Super Duty? A 120HP motor will move that 6500Lb truck easily, it won't do it with any kind of performance, it's be slow as hell and over heat the motor and it wouldn't last long. A bigger motor is capable of moving a bigger heavier truck much easier with less heat and a longer life. A bigger motor is capable of producing the same amount of power as your smaller one without heating up as much because it isn't working as hard, bigger rotor equals more torque, and a bigger can has more surface area to dissipate the heat better.

^^^ yeps

Plus you wrote in the stipulation that you want a cool system no matter what. You just aren't going to get it w/ that sized of motor w/ that level of power demand (maybe if you went to a high voltage setup, but not on what you got now.)

I don't see how just switching one brand of motor for another is really going to get you anything. Neus are arguably the best motors on the market. Ditching it for a Tekin that is 200kv lower isn't going to do much for you.

If you really want that much power, need a bigger motor to play safely. Someone here has a 1521/ 1Y (1600 kv) for sale. I would just get this. Tone down the insane rpms, and use the greater TQ to pull the gear, esp w. the gear limited Muggy. A 1521 on 6S, that bitch will be fast. Not sure your batts are up to it, but thats another story.


Personally I would just do this first, and not waste my $$ swapping around escs and all that. I'd save the money for bigger batts down the line. The controller should be fine. Else drop to 5S like Mike said and be happy w/ what you've got.

Oh, and castle is FOS. There have been a few arguments about this.

On one hand they tell people to rev the motors to the moon, and gear for 80mph and their system will handle it. It can handle anything.

When stuff breaks they say people shouldn't abuse their hardware, and what did they think will happen. People should visit forums on how to get up their cars. They can't possibly guess what will work where.

Alot of having their cake and eating it too I think. Castle is good, they just seem quite stubborn on this point. Take what they recc w/ a grain of salt.

I sure wouldn't put that motor in that truck, and it sure wouldn't move that truck easily! I was asking an honest question, not making a point, and the reason is that I just really don't get it. The reason I don't is that the motor has so much torque that I can flip the truck and land on the wheels again, and if I gear higher, it is so fast that above 60ish, it REFUSES to stay on the ground; SO, I don't see how I need more torque. I'm not saying I DON'T, just saying I don't GET IT.

And I kinda still don't, for the reason stated above. Sorry. Am I dumb for this??

It may be hard to tame the power of a brushless motor, for that you'll need a smooth trigger finger. Brushless motors don't know their own strength and will work themselves to death. It's very hard to put it in words but there are some simple rules you must understand. If your system is running hot enough to burn something up you have something wrong period!!! If your melting down motors and ESCs you are asking to much of them. Either your vehicle is to heavy or your geared to high causing the motor to draw a lot of current, that current also passes through the esc. You need a bigger motor on higher voltage that will draw less current for the same speed or get reasonable with your speeds and gear the smaller motor for a reasonable speed. A Muggy at 55MPH will most likely be unstable and hard to control and I will be the guy to say it, you could hurt someone or do lots of property damage with a 13Lb truck going that fast that is out of control! IMHO get a bigger motor, it'll last you longer because it won't be working as hard, gear the truck for 35MPH and work up from there until your components start getting to warm and then drop back down a tooth. Then be happy that you have a setup that stays cool and isn't breaking down all the time and deal with the fact that your not hitting 55MPH!!! You asked for help and we are all telling you the same thing yet you won't listen.

fair enough, I've been known to have a head like a rock!

ok, SO, I'm willing to go down to 50mph. As for safety - I agree, and I take that VERY seriously - we all should. I agree that something is wrong here, that's why I've asked Castle what is wrong with my setup about a dozen times, and they INSIST that my setup is spot on. Well, if it is then the MMM sucks, but if the MMM doesn't suck, then my setup is wrong. Either way, I'd really like to have an RC car that works, but something is wrong!

I haven't really been melting anything necessarily, my ESC just keeps dying (same thing?). Never actually MELTED something. Motor temps are highish, but closely monitored with telemetry, and my battery temp has never been an issue, even on a hot day. So, what would YOU do? I want to go 50 all day in a Muggy. What motor/battery spec (6S max)/ESC would YOU get??

The only thing I can come up with is the batteries might not be up to the task of 55mph. Its already been said, but 55mph and such a heavy truck is pulling serious power. Maybe the ripple current is getting you where the batts arent up to the task and smoking controllers. I personally run the 2200 on 5S and it stays nice and cool in my emaxx. I think the 2200 on 6S is a bit much, but I think Castle says its a solid setup.
I have been running the MMM on 4S and 5S and have had good luck with the V3s. I have run them enough times now to know the MMM is a solid speed control. The V2 did have the BEC problem which has been well documented and it happened to me so I am a believer, but the controller hasnt failed on yet.

I beleive that the MMM will do the job. I would try picking up a 1521 1Y motor, batteries must be capable of at least 150A continuous and I still wouldn't gear for 50MPH as you must account for the tire ballooning out at those speeds. I don't know the exact setup of a muggy so I won't make a definant gearing suggestion, but I will suggest gearing for 40MPH and see how that works for you.

ok, but how many cells would you suggest?

6s an the higher voltage geared for the same speed is going to draw less current

Ok, since I have a muggy, and run 6s, and run a MMM maybe I can give you some info.

I run a 1600kv hacker xl motor, similar in power output to a 1515. I am currently geared for mid 40s. My system will get the motor up to about 150f, and will get the fan on the MMM running to. I use flightpower 4500 30c 6s batts and they will get up to 130f. All that tells me is that my setup is working the batts hard. Loots of draw on startup, and lots to put back in under heavy braking. I have a feeling you may stop cooking escs if you step up to a better lipo. Something ;ike a 5000 30c 6s pack. If you still want 50+ mph 6s is the way to go, as it will allow lower gearing than 5s and help with voltage spikes under load.

My buddy runs a savage (not light) with the 2200 combo on 5s and it runs cool and does well, even geared up at 50. We geared it back down as it was a handful.

What the hell took you so long dude?? I always look for your responses! I guess people are right, and I should step the battery up - zippy has a 5000 6S 30C, so I'll get that. However, why is it that battery temps have always been good for me, depsite the low C rating? Is it because I have punch control set way high (or was it low - just so that I can only pull a wheelie from a hard start) and brake power at only like 50%, or is the C rating very conservative on this enerland based pack??

Also, while I like the idea of 6S, as I believe it's better to push the truck with voltage instead of current (which may be completely wrong), is 6S killing ESC's ya think? Is 5S safer for it, despite the rating?

BTW, are you using the 18T pinion when you are smoking the ESCs? Are you running 40 series tires? How hot is the motor? Could be that you are just way overgeared and putting too much stress on the esc and smoking it. The motor may be staying coolish, but the esc will fry. I would have expected those batts to cook a bit, but if they are staying cool then perhaps you are not stressing them too much. Maybe.. Linc could be onto something too. IDK from the provided info.

If you back down on the speed/gearing a bit, your setup should be fine. Pavement is a pretty easy place to drive. Grass driving gets things really cooking. Use trug/maxx sized tires and that will help a lot as well. If you want more, something will have to change.
The only muggy I drove was still nitro, and it was a big fat bitch. Takes alot to get those moving. As linc describes his setup, just for mid 40s it takes a ton of power, and it works the system pretty good.

If I was doing a Muggy for mid 50s reliably, i would go 8S (30C 4000mah+), 1521, and an MGM. I like to over-engineer FWIW, but I don't blow my $hit up either. Good luck trying to keep that hellcat under control tho :diablo:

Where in NJ are you? There are tons of dudes around there, and perhaps someone can look at it in person. Even hook up an eagletree and get some good info instead of making a bunch of guesses.

My runs are always on a smooth parking lot - no grass or dirt (I intend to get it on dirt someday). Not running 40 series, as I don't know of a tire that can take this level of abuse in that size. I'm running HPI phaltlines, which are street tires slightly larger than standard truggy tires. I'm running a 12T pinion - 18T simply doesn't work. I can't go smaller than 12 though, it won't reach the spur. The motor temp is very dependent on weather. If it hits 170, I stop, but that only happens if the ambient is 70+. My battery has never gone past 115, and the MMM fan is almost always on, regardless of outside temp.

I'm in Old Bridge and willing to drive some at this point!

Damn dude.. a 12T isn't that crazy on those tires.... Have you tried taking the punch control off? Maybe there is some weird setting like timing etc?
Seems like something else is amiss...

yep, punch control is WAY down - 40%, timing is normal, brake power at 50%, reverse at 30%. Wiring and gear mesh inspected a thousand times, and on every failure, nothing was even being used hard! This is why me and everyone at castle can't figure out what the hell is wrong, for the last YEAR.

And as much as I would love to just get an 8S MGM and a Neu 1527, and the most expensive 6S battery I can, I just took a MASSIVE pay cut at work, so I'm screwed. Big time. Oh, and I need 2 new sets of tires, and I really would like to buy the parts to convert my hyper 7. Oh, and it too needs 2 sets of tires. Lame.

If I wanted 55 out of my Muggy I would go the route as Finnster said, 8s and 1521, that why I said higher voltage on earlier post. I have found, like Linc, that about 45 is max with a moderate 6s battery (Neu 4300 25c) and 1515. I gear for about 40 with my set up and can drive it all day.

I would go for the battery you suggested. It is about the cheapest way to do some swapping. Higher voltage is always better. Now do you run the truck at full throttle all of the time, or do you spend alot of time at partial throttle?

mostly WOT in parking lots. I admit, I can't get enough of it; watching this truck go that fast is like crack! However, I do kind of want to avoid going to the 1521 if I can; at this point if everyone agress I need to lower the speed then I'll have to deal with it I guess, but the easiest thing to do is go Zippy 6S, RX8/T8 combo, so if it means lowering speed, then ok.

Here why I don't want a 1521: I have to seal the can, grind the shaft, wait a while to get it, and it will be the most expensive option. If it really will achieve something, then I'll do it, but the tekin combo is easier and cheaper.

Well you already have a mmm right? Even if it's out of warranty it's $70 to get it fixed. A neu 1521 1y is $275 new, so for $345 you'd be set. The rx8 combo is the same price but doesn't come with the hotwire, that's like an extra $35.

I think you are looking for a technical excuse to buy yourself an RX-8. Nothing really wrong with that at this point - we have all done it when something new comes along. I'd just hate to see you posting on here in two months with the same symptoms on your new system. I too am tempted to come up with a reason to buy one of them!:intello:
You have been given many examples of similar setups that run the way you want yours to, I think maybe the key is driving style as you seem to run yours somewhat different than most of us. I'm also suspicious of when you stated it really is dependant on ambient temps. Unless you are running in 100+ degree temps (and on hot pavement) for an extended period, it shouldn't put your system into an overheated state. I havent re-read the thread to check this, but how well is your body vented? Maybe its something as simple as that? Try doing a few runs with the body off and measure the temps.

Like I said in my pm to you, my Flux runs very well on 6S, and its about as close as you can get to weight and motor set up to your muggy, and its geared for about the same speed.

I'm sort of in the same spot as you are. I'm setting up a HV Muggy for about 35-40mph. From the beginning I was having a lot of temperature issues caused by high amp draws. I switched from a 80mm medusa to a Neu 1521, and still had temp issues and high amp draws. The Muggy would still fly though. I even test ran a 60mm medusa in the Muggy, and it would still fly. Like someone stated beore, these brushless motors will do about anything. They'll just pull as must amps as they need and are supplied. Small motors will heat up with these amp draws and larger motors will stay cooler.

I rebuilt my diffs a few times to check for any binding issues. I didn't find any issues with them at all. It took me a few months untill recently I found a setscrew was missing in the rear right cvd. The pin in the cvd had come out and was causing some serious binding. Now the cvd is bent and useless. I'm waiting for some new cvds to see if my problems are resolved.

I was told in this forum a few times I probably had binding issues. Just took me a while to find them.

Also, I found the eagletree datalogger was a big help. really lets you know whats going on in your setup. Probably a better investment than getting the RX8. I have recorded a high of 4000watts (geared for 40mph and with binding in the drivetrain).