Too hot?

[Thunderbruiser]

ok so i got myself a traxxas slash and had been running it on 6 cells with mamba 7700...well now i've went into the garage and built some 8 cell packs...on my first run with one of the 8 cell packs 3700nimh(matched stick packs) the batt was 170,esc 130,motor 140 ish...

is that too hot for my car? geared 20/86 everything is set on high in the mamba...

maybe drop the start power to medium?

[rootar]

well according to the speed caluculator your spinning your motor over 60,000rpm which is bad for the motor, and your geared to do over 70mph, i highly doubt it is running this fast due to the batteries being horribly over worked and them dropping ALOT under load (why your battery temp is so high), the nimh pack you built wont last long if you run it at those kinda temps more than a handfull of times. id switch down to atleast a 5700 motor or even better a 4600 and keep the same gearing and youd be at over 45mph

also leave the start power on high but turn your motor timing to LOW its much easier on 2 poles motors.

[Thunderbruiser]

well i should drop the pinion to an 18tooth then right?

i don't have the 5700 and the only reason i am running that count is because the motor says it can safely run it

[Thunderbruiser]

i think imma just toss the og setup back in since it's running soo hot cause i don't have a 5700 on hand...i read on the motor that 9.6v max is ok 8 cells or 2s lipo max...so i guess it's just the drivetrain

[brushlessboy16]

are you saying the driveline is causing the heat?
try dropping to about a 16t pinion.

[Thunderbruiser]

i dunno dude i just put the stock stuff back on that setup can run 8 cells just fine..it sucks though speed wise...oh well...i'll be getting a 5700 and i'll do just fine with 8 cells

[brushlessboy16]

your geared to high, that is the problem, not the drivetrain

[rootar]

you can keep running your setup, i just dont see that motor lasting very long driven on 8 cells, but if you do keep running it id say atleast gear down to 90/14 or 90/13 those would put you right at about 50mph plenty fast and it still be hard on those batteries but not near as hard as when geared for over 70mph......

Wow, perhaps Im dumb, but the esc and motor seem more than fine. Only thing is the battery is getting way hot. Try a 2s lipo and see how that works out for you. The 7700 is going to require some pretty high current that those nimh aren't providing, thus cooking your battsery. The ESC and motor seem really cool to me considering the gearing and the battery. If you really do want to keep using that battery, then yeah, try gearing it down some more. I'm surprised at everybody's responses. Keep your start power to high, disable punch control, and set motor timing to the lowest setting, you should be golden.

[lincpimp]

Yeah, you are way overworking the battery. If you want to continue using 8 cells with the 7700, just gear it down. Drop down to a 15-16t pinion and it should be fine. I would personally invest in a good 2s lipo, like a trakpower, before buying another motor...

[rootar]

i guess we should have asked what he was checking his temps with. and how long are you running and what kind of driving you are doing before checking them?

i ran my slash today for 55minutes straight my motor 9L was 135, mm was only 127, and crapamps 3s 5000 was only 96......it was 90 outside

i bet if he puts batteries in there that could put the current that is needed he'd have much worse problems especailly in the esc and motor temps, his nimh batteries are the weak point now but if they werent everything else would be smoking hot garunteed

[Thunderbruiser]

i was just testing the batt out in front of the house id say maybe 7 minutes it dropped pretty fast and then when i temped with micro temp gun those are the numbers i got...i did take the motor off as i don't have anything lower at the moment maybe after i get it right i'll put it back in...but for now the stock setup will work just fine...ya know and i'll be getting some more lipo's just not now money doesn't permit so i was just making packs cause i had the batts to do it

[Thunderbruiser]

i checked the calc with adjusted numbers guys and it still says it's overrevving..yet the motor says up 2 8 nimh...so i dunno what to do... i'll get some pinions when i get back and try them out to see how it does....also i'd be running it on a small track with a buddy...so should i gear it for about 40-45? to be on the safe side? as opposed to 86/15 with 50mph according to speed calc

[TexasSP]

Keep the motor and go with 2s lipo like linc said. That motor is made for 2s which is 7.4v not 9.6. Your just overworking the poor thing and stressing the batteries.

[Thunderbruiser]

yea i'll need another slash first...the other one is remaining spec as i am too lazy to swap systems out for a race lol