Maj_Overdrive

My Feedback: (11)

I personally like 5s a lot in my rigs, plenty of power to really haul them around and its just enough of a handful. 6s is getting on the nutty side and starts to strain the drivetrain IMO. Things like diff cases flex and there's just a lot of strain on all the diff gears.

The 5s 4200 35c pack you ordered is a good pack for the truck. For a typical 1/8 you want a pack that can supply 125-150amps constant and you get that with the pack you ordered. I run 5000 25c packs (125 amps) in my LST XXL with the big Castle 1717 and they never get much above ambient temp let alone puff. More is always better and provides some headroom so nothing gets stressed and fails. In the case of Lipos a pack that can't keep up will puff. Some lower quality packs have what's called ripple voltage that can hurt an esc, but it's really only a concern in the higher powered stuff. I'd put the stock G3 in low-mid powered as far as 1/8 is concerned and wouldn't worry about packs hurting the esc.

HerrSavage

How do you program the ESC for 5s? A guy in a German forum is saying it's not possible..

Foxy

German guy may be right, there are quite a few ESCs which don't like 5S. If you have the option to specify total voltage to cut off, simply set it at 3.2*5=16v, rather than specifying how many cells explicitly, this is an effective workaround for quite a few ESCs. Of course knowing that your cutoff should be 16v, you can leave it in 4S mode and set the cutoff at 4v per cell. That will work too, as the ESC will only look at the total volts, it can't inspect individual cell voltage through a deans plug.

HerrSavage

Just hooked up the Hobbywing program card. Only reads up to Item 5. So I guess I need a more advanced ESC to use the other stuff?

My LVC was set at 3.0V?!!... Changed it to 3.4V. Guess that's why I was getting decent run times....

I also changed the brake power or whatever to %50, since I think I've heard people say to do that...

Foxy

50% is a lot of brake power in a 1/8th.

By the way, I run all my LVCs at 3v, recommendations for high cutoffs stem from the fact that lipo used to be dangerous and short-lived. This is no longer the case. Setting the LVC to more than 3.2 is just wasting runtime if you ask me.

Haddi Taha

+1 I use 3.0v and have never had any issues and all my celles end up around 3.5v when I put them on the charger if the lvc kicks in

But one of his packs always has a cell that finishes at 2.9v so it may be better if he sets his lvc at 3.2v just in case, and it will probably make 2 minutes difference in runtime

For 5s you just have to set the lvc to 2.8v so it recognises the 5s as a 6s but if you want to run 4s or 6s afterwards, you must change it back to 3.0v or more

HerrSavage

Just went and checked - I had set it to 3.2, not 3.4. In any case, at least I've learned how easy it is to set the ESC for 5s - just go to Item 3 on the program card and change it from setting 5(3.2) to setting 3(2.8)..

What I'd still like to know is to what extent running 5s with a 14T pinion is a bad idea. Nobody ever mentions 13t pinions? Surely 13 would be a compromise between 4s and 5s, and would be fine for both? Would be nice to not have to change the pinion, and have one that worked for both...

Foxy

I use a 13 when I don't know what batteries I'll be using as it is the best middle ground, keeps the car in one piece on 6S and is quick enough (just about) on 4S. That's 13/46 on the Xray XT8 which also has a high final drive, so it would be like a 14 on other cars. However, your tires are bigger, so no real difference. If I knew I was going to be running 4S only, I'd bring along a 16 and an 18.

Also, this setting you mention for 5S...what do you mean change it from 3.2 to 2.8? You mean when the esc thinks it has 6S attached? The important thing is how many cells the ESC thinks it has connected at any given time. Assuming you want a 3.2 cutoff, if the ESC thinks it has 4S, set it to 4.0v per cell, if the esc thinks it has 6S, then 2.7, not 2.8 (assuming that's an option, of not, 2.8 will be ok)

Maj_Overdrive

My Feedback: (11)

As you know the bigger the pinion the higher the top speed will be with slower acceleration because of the increased load on the motor. This is just like nitro, and the electric motor will pull more amps with a bigger pinion just like a nitro will suck more fuel. The difference is the electric motor will heat up under increased load.

Now, an electric motor will draw a certain amount of amps according to vehicle weight, gearing, tire size etc. Multiply amps by voltage and you get watts. Assuming nothing is changed except you increase voltage (ie 4s to 5s) the motor will gain rpms, increasing top speed which increases load and heat. If your truck was geared for say 40mph on 4s and 40mph on 5s though, the load hasnt changed and the wattage used will be the same. But since you increased voltage the amps will decrease and the temps should be lower on the 5s setup. This is because the load on the motor is the same and the 5s setup has more power to work against the load.

This is generalization of course just to explain the concept. I'm sure there are cases where you can increase voltage without changing the gearing and be fine, but there's too many variable for me to say you'll be fine with x voltage and y gearing, maybe a fellow G3 owner can chime in with personal experience. My personal experience with 1/8 and motors similar to yours says that 50mph is going to be kinda borderline with heat. You'll probably be ok now, but maybe not so much in warmer weather. Try it out on 5s with 14t and check the motor temps every couple minutes on the first pack or two.

echthelion

about the LVC u could buy one of these http://www.amainhobbies.com/product_...-Warning-Alarmits alittle better because it plugs into your balance connector and there no need to reprogram your esc each time you change you lipo cell count

HerrSavage

Thanks.. I think I'm good with the charging, checking, etc.. now. (Hope so anyway...)

Changed from 50k to 100k in the middle diff today - WHAT AN AWFULL PIA.................... Stripped out a few screws, it wasn't meshing, sticky silicon oil everywhere, etc...

So anyway, keen to go check it now - new steering servo in , 100k in the center, and a 14t pinion. Would have tested today, but the weather has been unrelentingly horrendous.......... [:@]

I think I'm going to order a 13T pinion now, and then just leave it at that for both 4s and 5s..

Also want to order some HPI/HB hinge pins, as these are apparently the weak point on the truck.. And a spare spur gear, if I can find one...

Haddi Taha

Don't you have good access to associated spare parts?

Haddi Taha

My new Jconecepts Illuzion Ford Raptor SVT for Revo 3.3 body shell on my mt4. I accidently sprayed lots of black where there was suppose to be white but I used dot 4 brake fluid to clean it up. You wouldn't ven know I made a mistake if I didn't tell you

HerrSavage

Looks good.. I'd do black though - white will look thrashed pretty quickly.. I just paint everything black now. All bodies end up thrashed, and black sort of still looks cool all mangled up..

Yeah, I have AE parts here at home even. But I've heard mixed things about running steel spur gears - as in it can be bad..

Haddi Taha

I also like black alot the only issue is that I have problems seeng them at night. I plan on converting to a truggy later with black proline mugen mtx6 shell, black wing and black wheels, its going to look epic

To use a steel spur gear you need a stronger hardened steel pinion like the Robinson Racing ones so the pinion can handle the abuse.

Everyone had their own experiences with plastic and steel spur gears. I like steel gears much more as they never strip but I won't use one without a center diff or slipper clutch.

HerrSavage

Well I have a 14T RR pinion in right now, and wouldn't mind buying for ex. a 13T too..

It is also pretty hard to find the 50T plastic SG as a spare part.. I've probably even got a couple steel 50T RC8 SG's around.. At least a 48T or 52T...

speedeur

Hi from France. For the choice of my combo I will go with Xerun 150 A and a leopard motor the 4274. Can you confirm it's a good choice for my MT4 ??

Haddi Taha

perfect, what kv is the motor? Are you going to be using 4s or 6s

Foxy

This is almost the same as the electrics that are in the car from Thunder Tiger. Good choices.

Foxy

It's a 2000kv, so its ideal.

HerrSavage

I think I've read that the stock MT4 motor is a rebadged Leopard, and that there is another Leopard that's even more powerful(and prob not much more expensive..)?

Foxy

I believe its a hobbywing. As for 'powerful', in relation to electric motors, you can think of stator length as being like displacement for engines. The longer the stator the more torque (as a general rule, other factors are also involved, suffice it to say that under most circumstances, regarding two motors of the same diameter and architecture but different lengths, the longer is the more powerful.

speedeur

Yes I will take this 2000 kv motor and I will run with 4s and 5s lipos I think. The leopard 4274 have a 4.2 cm diameter, is the motor mount ok for this size ?
It's this one :http://www.leopardhobby.com/product/...ionID=01020220

Haddi Taha

Speedeur, thats motor should work perfectly

Foxy, I don't think its a Hobbywing, the only smooth can (no fins) hobbywing 1/8 motor are the sensored buggy ones. But they are probably made in the same factory or something with all the other chinese motors

speedeur

Cool thanks for your answer I will make an order of this combo. Can you give me an idea of wich lipos I can take for it ?