anyone run 3S in a Truggy?
 

Just out of curiosity, is anyone running their truggy ( or tested their truggy ) on a single 3S Lipo?
What sort of speeds would be possible "theoretically" without puffing the pack?

People who are geared for 25mph might be...

Not sure what kind of info you are looking for, but higher voltage is always better. Lower voltage will demand the use of a very efficient motor, such as a neu, to perform and not kill batteries. You still need the same amount of power to get those truggy tires turning and move the weight of the vehicle, regardless of how much or little voltage you run.

So you will need the same physical weight battery, regardless or voltage to get the same runtime and power. So either a 3s 10000mah, or a 6s 5000mah, for example.

You will need to run the same size motor for any given voltage, for example you want motor rpm around 35k rpm, and want to move a 10lb truggy. A neu 1515 is a tried and tested motor that can get the job done. You would need a 1600kv motor for 6s, or a 3200kv motor for 3s. A 3200kv motor in a 10lb truggy geared for 40mph on 3s lipo will be pulling some amps, I bet 250 or more spikes, and well over 100 average. Stuff gets hot at that level, esc, motor, wires, plugs, etc. Plus you need a good battery to handle the load.

Higher voltage is just better all ways round. Now that we have the MMM, an inexpensive esc capable of 6s, there is no reason to not run 5-6s in the heavier vehicle. It just makes more sense. Going even higher in voltage would be better, I would prefer to run 8s, 10s or 12s. My varied experiments with 8s and higher have been very positive, especially on heavier vehicles and higher gearing.

Not a good idea really... 35mph tops is about what you should expect using a pack with something around 6000mah cap... the currents will be too high for comfort using such a low voltage.

You would need a very good pack to do this, at least a 30C and 6000mah or more of capacity.

Why would you want to run such a low voltage pack? You really don't want to go below 4s lipo, even then you need a good quality pack for a truggy. It's just asking for trouble, everywhere, pack, esc, motor.

I run 2s for training mode for my son - 4S gearing so get about 20mph...

thanks guys, I was just sitting at work wondering what sort of speeds would be possible (you know . . .wasting time at work bored), thanks for the answers.

Most everyone will advise against it, but most also have never tested it out and continue to advise against it via heard word. That's fine and if you want to stay cautious, that's good.
I'm one that has no problem running 3s on my truggy. No batteries, my truggy weighs about 7lbs. It's really not that heavy of a truck and I don't have any fancy CF parts either to lighten it up. I don't run a single 3s pack, but 2x3s packs in parallel. Each pack is rated for 90A, so total of 180A capable (supposedly). On 3s with my gearing, my truggy hits about 40mph. I've bashed and run at the track with zero problems on 2x3s packs. On an 80F day at the track, my ESC was 80-90F, my motor was 90-100F, and my batts were 100F.
I've tried running single 3s packs a few times to see what happens (and I really wanted to get some runtime in and was impatient) and 2 of the packs had 1 cell die (so 3s became 2s). No puffing. Just a dead cell. Need to open the packs up and either make another 3s out of them or make a 4s pack.

Is it the best scenario? No. It's true that it pulls more current. Less current is better.

Is it a setup that can run with no problems and everything stays cool? YES!!!

In case you're interested to know, my BL setup is an EZRun 150A ESC and 3674 motor. I also run on 4s. Not a super efficient, high dollar setup. Yet it still runs great and allows me to pass nitros at the track and out jump them on the jumps that don't have a lot of runway to pick up speed.

BS

I run 6s, Neu 1512 3D(1700kv), when geared for 35mph I get ~130F for motor, and up to 100F for my highly modified Quark, that's on a 80F day at a race... the temps are more like 150+F when bashing.

Sure you could get those temps, if you were crawling around going 10mph. lol

Call it what you like. Those are the temps I get. I'm not full throttle at the track except on the straights, which aren't that long and run for about 15 minutes at a time, so my temps aren't that high. Even when bashing, my temps have never exceeded 140F on an 80+F day. I've yet to run it when it gets really hot here (90-105F), but so far so good for me. Believe what you like, but since you've never tried this setup, been at my local track, etc. then it's only your opinion based on your experience with your particular setup. My statements are facts from my runs and experience with my setup.

i think ur facts are wrong as well, i also call BS if it was that simple every one would run that setup

BS as well, I run 4s1p 25c 5000mAh packs with CC Mamba Monster 2200kv 48t/15t gearing in my 8ight-t i see 125-135f temps on motor 125ish+ on ESC and 100f on batteries on a 90f day. Temps on a 3s are going to be more then that. Retemp or quit reading your gun in Celsius mode.

they way you write it, I would believe your figures. It's easier for people to say "noo, that doesn't work"... still, it's hard to believe.

the negative of high voltage is the extra weight. 4000mah 4s is lighter then 6s 4000mah. every gram of mass extra, you have to accelerate and stop. this causes stress on the components. your cars isn't heavy, so it's not that hard work for a 74mm motor.

I have once read, that in 1:1 car racing every extra kg requires xx horsepower to be the same fast. that's why I don't like today's cars with all that electric extra stuf nobody needs. that's why I like my vintage benz...

I call BS too. I raced quite a bit with a 3s setup in a buggy with a 1512 1.5d (3300kv) motor. It worked pretty well, but the battery temps were pushing 140+ degrees. I eventually puffed a 3s 6000 25c PQ pack and used a 3s 8000 Maxamps pack. There is no way a 3s setup geared to run with nitros on a medium to large track is going to run efficient.

On smaller tracks, 3s is more than adequate though.

I wouldn't say that the motors and esc run dramatically cooler, but the batteries definitely aren't nearly as strained. The batteries on my 5s setup rarely break 100 degrees on a 80 degree day as long as I don't run them down to the LVC. As batteries improve, it may be possible to run lower voltages without much risk though.

The difference is in the efficiency/run time. I can get the same run time out of a 5s 3300 that most guys are getting out of 4s 5000/5500 packs. I know people racing with 6s 2600 packs. I have RACED a full 24 minutes straight during an A Main to LVC on a 5s 5000 pack on a big ass track. There is no way a 3s or 4s setup will ever get that kind of run time.

Your statement may be true that addl weight causes addl stress, but that is not a negative of higher voltage setups. If you run a 4000mah 4s pack and go to 6s, you reduce the mah to get the same runtime. The weight of a battery per watt is pretty much fixed. So if you want X mins of runtime at X speed you will end up with the same weight battery regardless of voltage.

Basically a 4s 4000 packs will equal an 8s 2000 pack. Keep in mind you will run a motor with half the kv for the 8s setup compared to the 4s. Plus amp draw will be less on the 8s setup (half or more) and that will provide better efficiency due to the lesser voltage drop on the 8s setup.

There is no negative aspects to a HV setup. Currently not alot of choice in escs for cars over 6s, and finding a good charger can get expensive. Also, 6s seems to work well for 1/8 scale, so no real need to go up to HV unless you are going for higher than normal speeds, or have a very heavy vehicle.

And guys, don't jump on jsr so hard about his results. He has not listed his gearing, so we have no idea what speeds he is getting to, and we have not seen the track either.

Given the fact he is only running 15min I think this is why his temps are so good. I set all of my vehicles up to provide 25min min of runtime. The first 10 mins barely gets anything warm. Plus his esc has a fan and his motor may well have a fan on it too, as it is the HW system. Plus if he uses decent batteries that will keep system temps down as well.

His recomendation is based on his usage, which is the only thing I can fault him on. If you want a truggy capable of 40mph+ and 20+ min runtimes, 3s lipo will not be the way to do it. Not easily. 4s is marginal, 5s is much better.

I was thinking of using a a 3s 8000mah 20C TrueRC pack in a 3.3 Revo conversion running a HV 6.5 Pro on my small LHS track. Sounds like this might be Ill-advised even considering the Revo conversion is pretty light weight ? The track is almost always dry and dusty so I was thinking 3s will not be over powering and provide adiquet power with the tracks surface, Now I'm Confused ??

It's all about gearing. You could run 2s if geared low enough.

Most people recommendations to run 4s+ on anything larger than 1/10 scale stems from the typical 8th scale weights, along with typical 8th scale speeds (35-45mph). Obviously, drive style, ESC settings, and terrain all play very large roles in how any setup will run.

A truggy basher running the "recommended" 5s-6s on a 1800-2200kv motor could still experience temp issues if they treat the trigger as an on/off switch, while running in grass, with max ESC setting (100% punch control, highest timing, etc), geared for 50mph+.

While a truggy racer running 3s on a 2600-3300kv motor could be fine because they feather the throttle, run on a well groomed track, with moderate to conservative ESC settings, and are geared for 30-35mph.

Just like 1:1 cars: A Honda civic (for example) driven by a grandma who can't even make the gas pedal reach the floor, will most likely last far longer than the same car driven by a lead-footed kid who treats each red/green light as a drag race.

Is the 3s setup in a truggy "ideal"? Maybe not, but I wouldn't call the poster a liar because he stated his experience. He could be a "grandma" driver, and the rest of us could be the lead footed kid.

I have been running my SC8E on 3s 8000 with a Neu 1515/.5y/S with a Losi Heatsink 14T pinion.Its running the same temps as my 1515/1.5D/F ON 4S 6000 15T pinion.I also put a fan on the motors.And the MMM fan comes on but never gets as warm as the motors.Its the Battery that shows signs of heat with the 3s setup though.

haha we all talk about temps and temps and temps but honestly after two years of racing 1/8th electrics and building/setting up over 14 1/8th scale cars the BIGGEST varition ive seen in temps is just handing the remote to someone different....


GREAT example, i setup a Losi8 the other weekend with a MMM, $40 ezrun 2350kv motor, and 4s 5350 pack geared for over 40mph, and the ezrun motors have those HUGE fans on it, i let the guy drive it around for 10 minutes and he never broke 120 on that cheap motor or 100 on the speedo and it was 95 degrees out side, he gave me the remote for 2 mins i had the temps up to 165 on the motor, 145 on the esc, and 125 on the lipo...... in 2 mins! i gave the remote back to him and he ran 5 more mins before it started to slow and when he pulled it off the temps were back down at 125 motor, under 100 esc, and right at 100 lipo......

i personally run 5s in my truggy and after a 6 mins race im at 160-170 on the 1515 2.5d motor and 140 on the mmm and 110 on my rcm lipo, so if a setup works for you doesnt mean itll work for someone else, i drive the hell out of my truck every time it touches the track, i have the track record at 3 tracks in the state with it and run those kinda times every race, but when i hand my radio off to others they could run it for over 20mins and temps would be low, with me driving i cant run more than 10 at my race pace....i can also tell a HUGE difference in runtimes my gf drivng my truck can run it for over 25mins on the track while i can dump the pack in under 14 now....


what im getting at is yea you could make a 3s setup work, but if your buying a system... go low kv and high voltage their are no down falls. if you already had a mmm and 2650 motor laying around im sure you could run that in a truggy fine on a PAIR of 3s in paralell with fairly low gearing.... but dont purchase a system with the intention of running 3s...

:rofl: thats a good way to put it brian, my driving style is FULL throttle, FULL brake, if your not on one or the other your not going fast enough :yes: the basic idea behind my racing style is to get in,through, and out of the corner as fast as possible, how does the saying go straights are for fast cars and corners are for fast drivers....:yipi:

Well, I don't really want to jump on the guy, but I just can't see temps being that low under conditions that are anything remotely considered normal... granny driver would be the right way to put it, and geared for maybe 30mph tops, maybe something like 25. :lol:

This is actually interesting me, I am going to test my Revo out, and see 'what is takes' to keep the motor temps to 100F on a typical summer day.

jsr, can you please posts your truck, compete setup, gearing, batts, etc? thanks, we should all know this, it's very important me thinks in hindsight.

....y?

Truggy on 4s is a minimum for me.

Btw. These motors are designed to be most efficient while running 30-35K rpms.

I vote against 3S also and say 4S min. Fans can do wonders to temps though. Maybe thats how JSR keeps his motor so cool. I can keep my Feigao 7xl ice cold with 2 40mm fans and the novak heatsink. I've run it for years now without issues. Without the heatsink and fans it would not have lasted a single run. I was easily reaching temps of 170 without much effort without any of that stuff. 3S is something we used to talk about in the day when there were no such thing as 4S controllers and people experimented and came up with 3S just being too low a voltage for a heavy truck running a descent mph. I am having a bit of trouble though with the controller being at 80 to 90 degrees on an 80 degree day. Even my best MM on 4S got hotter than that with a 40mm fan on it. I would be interested to see if JSR is running any fans on his esc and/or motor to stay that cool.

Do you guys remember my Quarkinstien? That thing ran about 10F above ambient, but look at it! :lol:

http://picasaweb.google.com/SethHuls...31438369440434

Wow, for people who have never run this setup, or a similar one, you're all very undeniably correct in your opinions.
Some info on my truggy/setup/track:

TTR ST-1
Geared for 35mph (right now, need to pick up other pinions)
Weight w/o batts ~7lbs (complete with BL setup, wheels, tires, etc.)
Batts - don't recall the brand, but each pack is rated for 90A and I run 2 packs in parallel for 180A constant discharge capability
Fans - fans are installed directly atop both the ESC and motor. They keep both quite cool. They will thermal shutdown if the fan is not used. The fans do wonders for this setup.
Track - hard packed dirt, very tight turns with many jumps (mostly small, some quite big), front and back straights that are long enough to allow about 2sec at full throttle.
Usage - I DO NOT RACE. I go to the track for fun. I don't attend during the race days as it gets quite packed. Everyone at the track is just there to run and have fun. No one during those times are very good drivers. On the straight, the BL acceleration keeps up with the nitros. Only an 8ight 2.0 pulled on me on the straights. I can out-jump him as the track is tight and doesn't have much room to build up speed (and thus rpms) for a nitro. Full throttle and full brake doesn't work well on this track. The light dusting of dirt atop the hard pack often makes you slide (although I've never tried holeshots).

If you race, I'm sure your temps will run higher. The A-Mains are usually longer than the 15 minutes that I typically run. Also, considering my track has many tight corners, full throttle is rare. It's a burst of throttle here and there and part throttle through many portions of the track.

The OP asked whether 3s can be done and everyone just follows suit of the old adage of "no way in hell", regardless of what experience, or lack thereof, they have with a 3s setup. I'm simply speaking from experience that YES, it can be done and can be done without everything exploding destroying half the planet. I already stated in my first post that it is not ideal, but it can be done without worries. If that bursts your bubble that 3s is the end of world in a truggy, sorry. Fact doesn't always follow theory.
And also, friends that run Medusas run hotter motor temps than I do. I ran geared for 40mph during bashing and they get higher temps. Don't ask me why. Their motors are "supposedly" more efficient than mine, we're all geared for about 40mph, and they typically run hotter (everyone on 4s). And at bashing, we're all full throttle.

i just dont believe u can outrun nitro on 2 3s packs in parallel that right there is alot of weight especially if eack pack is rated for 90 amps of discharge, and u said the track is tight so ur on and off the throttle alot which is going to cause more amp draw, i dont know as much as others here but am i making a good point?

The short straights may help in my favor as the nitros might not be hitting full tilt during that time. The only one that's pulled on me thus far is an 8ight 2.0.
When I'm on/off throttle, I'm not hitting full throttle. A lot of it is partial throttle which won't draw the same surge currents as a full throttle pull. The only times I can hit full throttle is entering the straights and two jumps, of which if I don't exit the previous corner right, I can't hit full throttle either. Faster throttle changes will result in higher surge currents and more ringing (residual current bounce). Slower throttle changes don't cause as much overshoot.

So 3s + fans = success...

I knew there was a reason you were able to run it on 3s without thermaling. I have seen a few 1/8 buggies run 3s with the mmm/2650 combo and they did fine.

Are all of your friends that run medusa motors using fans on the motors? I am not really impressed with medusa motors myself, but they are better than a chinese 2 pole motor. Just the design alone.

i did not see the fan part either, its great the fans keep everything under 100 degrees when they would thermal without, ummm, but whatever works, different strokes for different folks, but im done with my 2 cents and being an ass,lol it just doesnt click for me but i dont know why u would so strongly defend BS if it was not true. so ill give the benifit of the doubt.

Yeah, sorry, I run fans on all my electrics. I make that as a must. They do make a huge difference. My friends do run fans on their Medusas. I prefer 4s, but my 3s are more reliable than my 4s.

After reading his setup, and realizing that i know him in real life and i consider a goto guy on all things BL, i know this to be fact as well. Johnny sorry i called you out the way i did, I did not realize it was you posting here SORRY. YES he can run this setup it is FACT.

U're right. I use fans as well on both esc and motor. it gives me worry-free bashing, especially on soft sand w/ my truggywheels (on a buggy). lower temperatures are also good for the motor's efficiency (losi 1700 on 5s). on the track (just for fun, not very fast track) temps are like that around 40deg c., now w/ the torsen center diff a bit higher.

of course, fans won't change or help a crappy motor and wrong setup.

I just converted the 7 pounds into kilogram, 3,2 kg for a truggy, I'm impressed!

pls post some pics.

There are pics somewhere on this forum. I can't search right now but will try later. I should also note my friends don't use heatsinks on their medusas while I have oe on my motor. I have a 1/10 truggy that I broke the fan on and it ran much hotter than with the fan so they do make a huge diff. Once I get better 4s packs I will definitely run those but for now the 3s work fine.

3S packs in parallel can push out quite a bit of current and hold some serious voltage so I can see how they can still take out a nitro. You could probably hold over 12 volts (for a while) with 3S on some quality packs vs 12 Volts on some crappy 4S packs on voltage drop. I've bashed with some friends that have some pretty serious nitro setups and my 7xl just makes them look slow. I think its all the instant torque vs nitro having to spool up, but these electrics are pretty impressive.