Ez run geared low/running hot

[Metalhead Matt]

I started to build a track today(125'x75'), but didn't get to building jumps yet. It's pretty dusty dirt, with lots of clay in it, so it's packed pretty hard. I couldn't resist a test lap or 10 so I grabbed my rusty and made an ass of my self. To the point; running up and down the road wot, doing dounys, throwin' roost in the gravel, I can't get the motor over 120. After 10-15 minutes in the dirt it was 170. No driveline bind, Not full throttle all the time. It's geared 15/87 with duratrax nitro mt tires on it. 4200 8 cell tenergy. The esc didn't get above 105; the bats 120. Any ideas? If I gear it any lower, it would be on par with the fricken xl5, just with more pep. My top speed on the road is maybe 35-40. That's being generous. I'm planning on running this motor until it's junk because there has to be better options. Here's the specs on the esc: Cont. current=35A
Burst=190; resistance=.0015ohm. It says suitable b.l. motor.>9t. It came with a 3000kv/13t. Most of these specs are like greek to me. I'm wondering what a good motor would be to replace this one with when she goes. I'll be sticking to 8-9 cell nimh's for now. I'm not looking to break any speed records. 45-50 on road to show off would be fun, but 35-40 would be more practical for control. What do you guys think? It requires a sensorless motor. Thanks as always.

 

[x_doug_x]

if i was you i'd put smaller tires on the truck ... the combo you have sounds good, but i thought the 9t was a 4500kv motor? i as well have a brushless e/z run setup on my duratrax evader ext. it kept going into 50 percent throttle till i put a smaller pinnion, then it kinda ran better. the combo you have sounds like what you should have for what you're doing, maybe drop some more teeth on the pinnion, those big tires aren't helping.

 

[Metalhead Matt]

Thanks for the suggestion, Doug. That would be too simple for me, though! I like the bit of extra ground clearance. I added a wheelie bar and lost some travel. The tires aren't that big and it's a 13t motor. If I drop any more teeth on the pinion, it'll be slower then a stock rustler. I'm looking for a motor that can handle more. Would a higher kv motor and a smaller pinion do the trick? Like I said, my batts and esc are handling these conditions just fine. Or maybe a heat sink with a built in fan for the motor?

 

[x_doug_x]

from what i read 170 is a good temp.. pm sweet diesel and ask him , i'm suprised he didn't post in this thread.

 

[Metalhead Matt]

He suggested 140 I believe. I've heard castle motors are good up to 200. I just put the Mashers back on it for now. I'm in the process of building a track but there's no jumps yet. It's easy to fly wot around an oval! I'm still real curious about which motor I should upgrade to. But if it ends up being fast enough as is, I'll leave it alone and enjoy longer run times.

 

[sweetdiesel]

I didn't post because I believe doug had it right the first time, the tires are too large for your gearing. I would go with smaller tires or lower your gearing.

I always suggest running the motor at 140 or less regardless of brand.

 

[Metalhead Matt]

Stepping back down to the 2.2 Mashers did the trick. Even with the low gearing, the rotational mass of the heavier tires put it over the edge. They're only a 1/4 inch taller and slightly wider, but you can feel the weight difference by hand. And they work great on my pede. The ez run motor seems to be pretty robust. After I got it up around 170-180, it still works like new. Granted it only happened once. Now I can beat it like hell and it barely touches 120. I have to break my habit of over gearing stuff because I'm making the slow move to lipo. For now on, I'm starting at the bottom! Thanks for the input fellows.

 

[x_doug_x]

yw, now that you know where you are, go buy a handfull of pinions from the lhs and raise your gearing till you're up around 140 and stay there.

 

[Metalhead Matt]

I have more pinions than I know what to do with. 120's fine. It's gonna get a lot hotter outside. It was about 75 the day it got hot. And besides, it rips nice as is. Tons of pep and it tops out right around 35. That's on 8 cells, too. The lipo bugs starting to bite! I think my next step will be to have John the battery guy build me a 9 cell 5000 tenergy or intellect. Which ever the best cells are. Or find one on one of the cheap battery sites. All battery has pretty good deals on 6 cell 4600 intellects. I think I'm gonna try some out in my maxx. Let me know if I'm getting the "intellect name right".

 

[Metalhead Matt]

Had the rusty back out again today. Ran around the track for about 10 minutes and broke a shock(got some jumps built). With 15/87 gears, the 8 cell and 2.2 mashers, the motor was right around 225! No bind in the drivetrain or any other problems. It ran great the whole time. The battery was about 105 and the esc was about 100. I think this will be the last ez run system I mess with. You get what you pay for, so I'm not very surprised or bummed. I'm gonna run this motor until it slows down and then throw a velenion motor on it. Any other recommendations? The esc specs are up a few posts.