Well the rain finally slowed donw here and gave me some time to drive and i was having problems with the temps getting really hot. I am running a Mamba max brushless 5700kv in my car with 87 or 88 spur with a 17t pinion. The spur is neon yellow if that helps and i know theres 2. Didn't get through a full pack before it got too hot. Any suggestions on gearing it. I have tried 18t pinion and thats didnt work the settings on my esc are stock settings. I just dont wanna keep buy pinions and find out its the wrong one. Some info would be great. I have read the gearing on castles website but thats is a guideline more than anything. HELP PLEASE!

abyone??

hey bones. i'd like to help out as much as possible. i too run a mamba max 5700 in my hot bodies cyclone. what's happening right now is your fd (final drive) is too low which means the motor is putting out more top end speed. what you can do is increase the size of your spur gear or decrease the size of your pinion gear. doing this will increase your final drive which makes your motor put out more torque than top speed. this gearing will ease the load off your motor and will cool it down some as well as the esc.

what chassis are you running? and do you know what the internal drive ratio is on that chassis

here's how to calculate final drive

spur gear divided by pinion gear then multiply that number by your internal drive ratio.

so for example my cyclone has a internal drive of 2.4375 and i'm running a 105t spur and 32t pinion

105/32 = 3.281 * 2.4375 = fd 7.998

hope this helps

88/17*1.83= 9.473 is what i came up with. Now what does that mean? I am new to this electric stuff. I looked up the final drive and it say it should be 8.052. Does that mean since mine in 9.473 i should change the pinion to something higher or the spur to something else? I ultimately need to get ot 8.052 or as close as possible that i can no matter what system i am running brushed or brushless? Thanx help again! So i should run 88/20*1.83= 8.052

the fd you found online is a suggested number. by going 88/20 to get 8.0 you are moving toward more top end speed. what you wanna do is go higher than 9.43 maybe even to the 10.0 range..it won't hurt the motor. so increase your spur gear or decrease your pinion or both. whatever is easier.

also you might want to tone down the motor by plugging in the esc to your computer and lower all the settings.

ok tried the car with the new gearing i am running now which is 88/16 *1.83 for a fd of 10.065 and all the esc settings lowered to the lowest and the esc , motor, and battery fried. The battery expanded, the motor just quit, and the esc wires melted. I dont know what else to do. I took the motor out before i did anything and the car rolled freely nothing was binding. Now what? I have tried everything anyone has thrown at me and nothing has worked yet. suggestions again. Thanx

need help on a heatsink. which one? [link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXLKA2&P=7]1[/link] [link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXNDP1&P=7]2[/link] [link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXLNY7&P=7]3[/link] [link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXNPF9&P=7]4[/link] [link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXKVU2&P=7]5[/link]

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Well let me give it a shot. Welcome to the problem of brushless motors (excessive heat generation). I use them in my helicopters and these boys get HOT.

Problem: I assume are running your engine with basicly no air flow/cooling at 100% of its capacity. This will lead to over heating very quick. Dont worry there are solutions for it.

Questions:
1.) What ESC are you running. The small mamba or the mamba pro.
2.) What (motor, esc, battery) is getting the hottest. How hot is hot to you. 165F and up is not so good.
3.) What kind of cooling do you use currently?
4.) When you drift are you mostly at full throttle? Are you high speed drifting or more the small technical course?
5.) What tires do you use?

Once you let us know all that i will come up with a possible solution for your problem.

I am running a mamba max 5700kv so its the esc that comes with that system. The motor and esc are getting the hottest 170ºF. The only cooling i have is the body raised up so air can get under it. I run full throttle with the system settings at their lowest. No punch control, timing on its lowest, drag brake on 60% but i run full throttle on a course i make myself. I was told by a guy that running WOT is better than half throttle. Tires i am using is pvc currently which i know has part to do with the heat. I have been told solutions so far are to run a 14t or 15t pinion and see what happens if that helps run a heatsink with the settings set low and get airflow going through the car as well. The temps out side are low 70 high 80s variable winds with a heat index of high 90s. I think that should be enough information I hope you can help mkosirog . Thanx

I forgot to ask ... what kind of battery are you running. Lets assume you run a 7.2volt like most of us ... at WOT your motor is putting out 41040 rpm at a FD of 9.47 you are puttin out around 4300rpm at the wheels. hhhmmm thats some serious power i am running currently about 3000 rpm on the wheels i guess around 3500 - 3800 is optimum ahh well.

Well lets try to weed out the BS you have been told so far.

1.) WOT is better than half throttle --- well thats BS right there --- With WOT you draw more current from the battery throught the esc to the motor. Airplane and Heli engines are designed to run WOT but car engines are not. Physics say ... less current less heat.

2.) Set the ESC settings to what you would like them to be when you drift. Your system needs to work that way ... specialy since the esc and the motor come from the factory as matched (fitting to each other, meaning the engine cant request to much current from the esc).

3.) Temp outside is fine.

4.) Since you run WOT all the time the tires have no bearing on the motor/esc heat --- its more that you run WOT. The whole idear here is that slippery tires will allow the motor to spin at higher/max rpm --- making it run hotter.

Solution:

a.) Like i said set the ESC back to what you would like the settings to be. I would reset it back to factory right now with setting the break however you like it.

b.) You will have to run some tests ... not on the track. Take the driveshaft or the belt out of the car. Then reset the motor pinion. Make sure its not slipping. Mesh the motor pinion and the spur gear ... make sure a paper fits in between ... you dont want the mesh to be too tight ... then run the motor like this for about 5 min at 50% throttle and check the temp. If you are too hot ... send the motor and esc back ... then they are faulty (motst likely a ballbearing problem in the engine) ... if not let it cool and run on 75% for a few minutes and look at the temp ... should be higher but nowhere close to 170F ... let it cool and hook up your front wheels only ... repeat the 50% test

What we are trying to do is figure out where the heat comes from ... it has to be a.) the engine b.) something is to tight and is putting to much stress on the engine ... makeing it overheat. Usual suspects for binding (and here i mean very little ... something you might not even notice that much while working on the car) are diff's, gear mesh, ballbearings. (a single uneven ball in a ballbearing can theoreticaly be the reason for this) You have to understand that something very little will have a hugh effect at 10k rpm

c.) cooling ... motor and esc should have a heatsink ... always ... since you run brushless in a drift car you might even need a cooling fan to add some airflow.

On last tip ... take your time ... go slow ... and you will find it.

I will be checking in on updates ... good luck.