FinishLineSport

iTrader: (1)

For those of you that have this motor, I run tight indoor carpet racing with one 50-75' straight away and my truck is one of the fastest, but my motor temps get up to 180-200 degrees after 5-6min races...Originally I had a 27t pinion with 78t spur and I swapped that down to a 23p and 78s still gets hot, still fast...Timing was where it was when I got the motor, at -8 then plus the built in timing...Wondering if I should put timing to 0 on the endbell, and try a smaller pinion like a 20T or what...Im happy with how fast my truck is, just need to run cooler...Im wondering if the temps are causing the fade toward the end of my races or if its because my maxamps are dropping off so fast...I run the Gen2 rspro with maxamps 6500mah dual core 150c batteries...

Any help would be great...


I run a proline pro 2.

Jonny5

iTrader: (19)

That has a 2.72 gear ratio like the Slash correct? You might be under geared, causing heat. When that motor is in its "sweet spot" for gearing it will run between 110-120° and be ballistic. The temp you're running it at will degrade rotor strength quickly and eventually burn up the stator as well.

I plugged your gearing into a gear chart and that's what I would start at for a shorter track, which makes me wonder if you have a bind in the drive train somewhere. Was the motor new when you got it? Does it have the 12.5 HT rotor?

FinishLineSport

iTrader: (1)

Yeah it has the 2.72 and just like a slash. What would you suggest for gearing for a right track?

It is the d3.5 17.5 the certified hand built with that stator you mentioned...it was brand new a month ago, only few races on it.

FinishLineSport

iTrader: (1)

Sorry it was also the maxzilla...the $150 one...would having a lot of drag brake cause excessive heat? I turned up the drag brake high thinking it's be more controlled braking thN me slamming brakes...I picked up a 20T today as that was next size down my hobby shop had.

Lead-Lobber

iTrader: (1)

In my understanding of gearing, dropping pinion would increase speed, and increase motor temps. To decrease temp, increase pinion size, getting the ratio closer to 1:1. This decreases speed (and temps) and increases torque. Am I correct? Again, that is what I'm being told. I'm new to the "go fasts", coming from the crawling world.
Cheers!

FinishLineSport

iTrader: (1)

Idk trinity told me bigger pinion equals more heat = bad

Lead-Lobber

iTrader: (1)

Hmmm. Interesting. Maybe I misunderstood what I was told too. I'll have to verify. Good Luck!

JsK

iTrader: (10)

78/23=3.39 x 2.72 transmission ratio comes out to 9.22. Thats pretty low geared for a 17.5
especially a D3.5 with a 12.5 rotor. There has to be a problem
somewhere else in your system. Check for drag. Could be a bad bearing or your
gear mesh might be to tight. Could also be problems with the settings in your ESC.
Lower tooth count on your pinion spins the motor faster, Higher tooth
count spins it slower. 17.5 motors make a ton of torque but very little RPMs
hence the need to be geared much higher than a mod motor.

Your undergeared, excess drag or the ESC settings are off.

Lead-Lobber, maybe if you spent less time being a grammar nazi and calling people stupid you would learn something.

Bkautz

YESS!!! Drag brake to high will cause to to run high I had the drag set high in mine before and it ran up 180-190 I turned the drag brake down a bit and wow motor temps dropped to 140-145 after 7 mins on a 75/24 and was able to turn the motor trimming up and it's way faster had to turn down the EPA on my remote

FinishLineSport

iTrader: (1)

I'll have to check my esc but the drag brake is very high I know....anybody else think this may be the problem? My wheels spin freely, gear mesh is def not too tight and my motor timing on end bell is set to 0, but from my understanding puts the timing really at +20. I wonder if I should also Turn that down to produce more torque?

liquid g

iTrader: (46)

On my blinky sc10 I was geared from 22-24/75 on a tight indoor dirt track temps were usually 140-160

JsK

iTrader: (10)

Thats really low for a D3.5,I ran 28/75 on the same style track and with a Tekin
RS in blinky.

FinishLineSport

iTrader: (1)

Do you think my drag brake set very high could be the problem?

JsK

iTrader: (10)

Yes, or you are undergeared. Try running without any drag brake. If that gets
you back down to 100 or so you can start adding it back a little at a time.

FinishLineSport

iTrader: (1)

Ok...when you say under geared, do you mean too small of a pinion?