tekin rx8 with pro 4 4600 or 550 can 4.5 novak motors in losi scte's.
keep in mind i have like 10 rc's all the way up to a brushless losi 5ive. i have no issues with any solder connections except this SCT.
now 2 or 3 guys at my track are also having issues . all with rx8's running 2s.

nothing is hot. motor max 145.esc 90 to 110 F. has happened to me 4 times now with 2 different 35C packs. thunderpower and hyperion. once a deans .twice a bullet connector. never on the rx8 motor wires or the motor.
these batterys are a few years old and never had this problem on a small track.

always happens on the last frickin lap too. fully charged battery down to 7.5 volts after the 5 minute race. 14t pinion on my losi.
one thing i noticed is the motor wires are just warm to the touch. kinda struck me strange that they were.

what i would like to discuess is possible causes for this.
rosin core solder hakyo 936

yea yea cold solder joint is one. but why ONLY on this car and this set up and with a few different guys?

That motor and ESC combo is asking a lot of that lipo. Running mod is the only time you really have to have a higher C rated battery. that battery might not be getting hot but I bet the wires especialy at the solder joints are. I had the same issue when I was running two 2s packs in series in my 1/8th. was running good 35c lipos but the solder joints on the bullet connectors to the batteries kept coming unsolderd. I switched to 50c packs and never had the problem again.

yea i have heard that a few times now. it just baffles me cause solder melts at what?350 degrees? how could the wires get that hot and cool off in a few seconds.

I'm having the same problem. I run a scte with a rx8, tenshock sc411 4600, 14t pinion, and nano-tech 6000 65c batteries. It's always the positive that comes off and when I pick the truck up the wires and connectors are warm but never hot. Its getting really annoying and need to figure out what change.

i dont believe the "C" rating on all packs are the same. so next question is which battery is actually up to the task?

i just put all new tekin 12 guage wires on everything. a couple minute test on the grass and the wires were 130 degrees F! is 12 guage not enough for this?

I have had this happen myself. I was asked to come in here and post. These SCT's draw a LOT of amps and can heat things up quickly but really just heat up a weak point enough and break the solder.

Some things to be aware of. Use really good solder, really good wire, and if you use bullet plugs, make sure they are new and tight. Also, higher C rated packs will not heat up the system as much.

thanks, so the "real" solution is to run them on 3s. with a lower KV motor. ah but we cant:-(
how about silver solder?

Pics of said issue? Would help diagnose your problem and let us better help find a solution for you...

no pick, just a solder joint coming apart. IF hacker07 has had it happen to him it is not from bad soldering lol. connection is getting hot enough to melt the solder i guesss. it is a low voltage requierment (2s) and u end up with a high amp situation.

switch ur batterys. i was having the same problem today when running a gens ace. never happens with my good packs. im running the same setup as u. you want at least 50c

Thermal cycling problem causing fracturing in your solder joint. Using 63/37 Tin/Lead alloy solder will help keep the problem to a minimum.

Also, if you can, change out your Motor Wires with a higher strand count wire to maximize power transfer and minimize IČR Losses.

I would also add in that Solid bullets are significantly better than some of the "older" "Birdcage" style's of bullets.

I'd Say somewhere its a Soldering Issue. Never had a problem with my scte and tekin/4600kv... Make sure your wire is Pre-Tinned 100%, If your wire is not correctly pre tinned even a good joint will not allow a great contact.

so i went down one tooth on the pinion. i went with all new wire and solder and got a orion 90C 6500 pack. problem seems to be gone. made the whole night without issue.Wires are not warm any more.

so my theory is voltsXamps= watts. motor draws lots of watts. we only have 2s to work with . an old or lower C rated battery looses voltage under load so to maintain the same watts the motor is drawing the amps go up. amps cause heat and that is why this only happens on a low voltage 2s high watt draw system.
so you need a super good battery than doesnt loose voltage under load over time.
i also set up my wires so the deans connector sits over the fan on the rx8. may keep it cooler. cant hurt.