PLEASE HELP ME!! (pick out setup)

[mk351e]

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

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?

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.

[What's_nitro?]

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.

[lincpimp]

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

[bdebde]

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

[E-Revonut]

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:

With the gearing I am running and current it is drawing the motor does need some time to cool down between runs (but it's ok...so do my nerves!). If I can get a handle on all the power the 2200kv system provides I'll be going up to the 2650kv motor with the same battery and gearing. It's currently geared for about 140mph, the 2650 would take it up to about 170mph according to Mike @ RCM.

[TexasSP]

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?

[lincpimp]

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?

[_paralyzed_]

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.

[lutach]

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.

[lincpimp]

Originally Posted by lutach

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.

[brushlessboy16]

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..

[mk351e]

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?

[Finnster]

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

[mk351e]

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??