I've got a 19t on now and I've got up to a 22t. I'll try the 20t and see how that goes. Thanks for the info and can't wait to get it on the track saturday.

I was a die hard 4s guy, but I never ran anything higher than 2050 kv.
I settled on 4s and 1900 and had great run time and the car was great on the track.

I have taken the plunge and moved to 1400kv and 6s. I have not driven my car yet with this set up but I hope it is smoother on the track.

It seems that it will have more RPM with the 6s

14.8X1900=28120

22.2X1400=31080

I gues I should run a smaller pinion?
I run 15/46 on 4s
What would you guys sugest for 6s?

Great info here. I just find it humorous the we have typed this stuff a gazillion times on numerous threads lol

One thing I want to point out to the guys with questions. This voltage/KV conversation only works if you keep things constant. If you keep your 2650 and put it on 5s it wont help. You have to drop the KV of the motor when increasing voltage.

2650kv is only warranted up to 4S. 4S is "nuts" for a 2650 in a buggy. I ran 3S and it was fun but bad for runtimes. Plus, it wasn't smooth - it was like a 125cc 2-stroke motocross bike - lots of high RPM powerband but not much "grunt".

This year, I picked up two Castle 1800kv motors and 4S 30C Zippys. Much nicer setup. I can see where even higher voltage would be better. I do want to pick up a 5S 4000 to mess with. This setup also runs "ok" on a 3S pack I've got and in the only outdoor race I did with it this year, actually got very similar laptimes with 4S and 3S.

One thing you guys forgot to bring up is Motor Wattage. You can move from a 800watt 2000kv motor to a 1200watt 1400kv motor and higher voltage and maybe even still draw the same amps through an ESC. That would create more power and you'd want to definitely go to 6s for that. Would run cooler since you'd be faster and not on full throttle as much. A motor seems to want to draw at its wattage rating, it just has different RPM output with different voltage. I'd love to invest in a wattmeter and understand it better.

So, when doing motor calc - start with the vendor's motor wattage in the equation. In another thread, a guy with a Novak 4.5 running 2x2s lipos in parallel would be drawing 120A through his ESC - and he was saying it was having heat problems. That's apparent with such high Amps.

so what would be a good battery to run with a castle 2650 and a 14/45 gearing or should i changeing too? or shoudl i just trade the motor because i just bought it brand new the combo and i was wonderign if the esc is a good and than i trade the motor or should i keep it and buy another motor ? its in a losi 1.0 buggy

I have been running a 6S setup all year and cannot believe how much better it is. My car is lighter and handles better, the temps are much cooler, and I feel confident in my setup. With 4S I always seemed a little leery about the car finishing a race. Running the RX8/1400kv setup since they updated their ESC my car has been unstoppable.

Does anyone make a 6S battery 150mm long? I need it to fit in the Kyosho conversion kit for my 777.
It only needs to be about 3400 mah to equal the run time of my 4500
mah-4S battery.

The cars just work better with 5 or 6S. I have been running 6S for almost 2 years (I have a 5S car as well). The biggest problem with 6S is the shape of the currently sold packs. I will always recomend 6S to everyone but beware when shopping for a pack to look at the measurments closely to make sure they will fit in your tray (& under your body). I'm currently running Hyperion G3 6S in 2600 & 2200mAh size packs but had to customize my trays to get them in (2mm to wide or way too tall if you put them in on there side) for my Mugen with either RCM or Losi battery trays. The best fitting pack for my car was the Thunder power 6S 2650 (older 25C pack).

I thought the higher C rating would also use up more battery. Like having a bigger garden hose to flow more water. I thought you could pick a C rating that met the requirements of the motor and ESC, anything higher just isn't really needed?

Does that make sense. Like a 25C battery will give more runtime than an equal mAh size 40c.

This may be a lot of repeat information, but this is the first thread I've read that was dedicated to the subject and remained on topic.

ben

a 25c vs 40c will not likely run longer.

it will have more voltage drop under load.

so a 40c will make the car accelerate faster.

6S will run cooler because the motor will draw less CURRENT at the higher voltage, assuming the motor is the correct KV as said earlier. A 6s 3000 mah 1400 KV setup will run cooler and just as long because the CURRENT draw is less and the motor is more efficient at the lower KV than a 2200 KV setup running 4S.

A high C rated battery is not as critical with the higher voltage because the CURRENT draw is lower.

Both batterieswill do the same amount of work assuming everything is equal, 6x 3000 =1800 - 4x 4500 = 1800.

Higher voltage is more efficent at doing the work because it will draw less CURRENT and created less heat.

No, you are incorrect.

Higher C rated batteries have less internal resistance, and less heat is generated if the CURRENT draw is the same. Higher C rated batteries are more important as the number of cells and voltage go down because more CURRENT will be required by the motor to turn the same RPM which generates more heat in the battery, speed control and motor!

At higher voltages the CURRENT draw goes down if the motor is sized appropriately.

TOO MUCH CURRENT (heat) is what kills motors, speed controls, and causes batteries to puff or fail!

This is true, but...

At the power level of current motors used for 1/8 scale this would not be very noticeable IMO. 1/10 scale racers can probably feel the difference running on 2S or 7.4 volts.

More CURRENT is needed at the lower voltage so a more efficient battery (Higher C rating) is needed or too much heat will be generated because of higher CURRENT draw to overcome the higher internal resistance.

Any more questions on CURRENT draw and how important it is? Whats needed is a speed control that will show the voltage drop and CURRENT draw during a run. Will the Eagle Tree system work at high amp draws?

Last thing, Brushless motors will pull as much current as you let them until the battery pops or the motor burns up. There is no good way to limit the CURRENT pulled unless you lighten the load on the motor with higher voltage becaue the motor is more efficent and will generate less heat if a lower KV motor is used.

I've just built a Mugen MBX-6 with a Tekno V3 conversion. I'll be running Zippy 5s, 5000mah 30c batteries, along with the Tekin 1700kv system. Could you give me an idea of where to start out with gearing? Are you using mechanical brakes, or motor brakes, as I'm sure this would make a difference in motor temps. What kind of temps are you getting on the motor after 10 minutes? I'd like to get 15 minute runtimes so that I can run with the nitros. Thanks for any advice...