Disappointed with my new mega...should I be?
 

I was running a medusa 36-50-2200V2 with a 4S 5000mah in my rustler. I went from the stock vxl motor and esc on a 3S 4000mah and going to the medusa and 4S I noticed alot more runtime(atleast 40% more) and very cool temps. I figured more is better so I bought a mega 22/30/2 1770 with a 5S 4000mah. After running a few cycles and doing some speed runs geared 23/76 I had to stop alot to keep the thing from getting past 140 which I was told the max.

I then threw the 4S medusa combo back in to check the temps and they barely broke 100 most of the time I checked it was around 96(64 temp outside). I just don't get it to me the run time should have increased some and temps would still be cooler then my medusa. I could gear the medusa 30/76 and not have a problem and run cooler then the mega did on 23/76 gearing.

I'm not running a fan since I broke it but would prefer not to even run one. Now I'm thinking to just get a medusa 36-50-1600v2 and use this 6S 4000mah I have coming tomorrow.

The MM never even broke 100 anywhere on it; I do run a fan though.

Any thoughts would help.

sounds like you might be undergeared so its freespinning quite a bit. go up a tooth or 2 on the pinion.

Are you using a Mamba Monster or a Mamba Max?

I was running 30/76 doing pure speed runs with talon tires and I could only do 3 runs before I had to let it cool. I did hit 74.1mph by my gps.

Mamba max with mod one by artur done.

I would stick with 4s or 5s if you are game. 6s is going to cause it to let the magic smoke out I would think.

so the mega was running 23/76 when it was heating up?

you did go up to 5s so i still think your under geared cause free rpm on your mega is 32,745.

the medusa on 4s is 32,560 there pretty close rpm wise so you should try your 30/76 on it, it shouldnt heat up.

you steped down in kv and made up with it in voltage. its pretty much the same setup except for your gearing change with i think is your problem.

Artur said I should be ok as long as I try to stay under 50amps constant and so many volts...sorry forgot the number but if I set my charger to 4.1 per cell that should give me enough margin. I doubt i'm the only one trying 6S on an MM but if I see white smoke I'll know why.

That was my plan...same rpm just more effecient.

so your gearing should stay the same. you went to 23/76. wayyy lower than 30/76 on the medusa. go back to that you will be ok.

I just reread my first post and I didn't have it clear. I ran the mega on 5S with 23/76 and I ran the medusa 4S with the same gearing within an hour of each other tonight. Mega just ran hotter.

thats were you had me confused. the 30/76 threw me off

with the Medusa 1600 motor I would expect you to exceed 50 amps closer to 70-80 on 6s

I seen a post were a guy was going over 80mph(in a rustler) and pulling around 1100watts. I figure at 50 with 24 volts that's 1200watts so I might be ok. I'm starting to think that the mega just pulls more amps then the medusa and that's causing the higher temps. If I have time tomorrow I'll just gps both the mega and the medusa with the same gearing and see if there is any speed difference since they both have the same rpm(will really close). Just running both tonight it seemed the mega was abit faster but I'm not good at judging speed.

How is the timing on the MM? A 6 pole motor likes high timing to work efficiently. I had my Mega ACn22/30/2 in my MBX5T and with 14/48 it was running very good. I changed pinion to a 15 to test out a new ESC and the Mega was very hot, but after 7 minutes of hard running. I now have a FUN600-17, with the same 15/48 gearing and it gets very hot in about 2 minutes. The Mega is a power house and in a light vehicle you can get away with higher tooth count on your Rustler. In a heavier vehicle like mine, the proper gearing is recommended. A good tool to get is a data logger from Eagle Tree or BNB Products to see just how many AMPs your set up is giving you. Most of the time is just trial and error.

Timing is at 10advance. I might try higher. Really wasn't looking for more power just a better setup. With the medusa only on the hottest days did I ever have to worry about temps. I like that and will keep going until I find it. I do love the noise the mega makes as it slows to a stop.

Maybe I should just learn to quit while I'm ahead.

Thanks for the replies guys.

I took my medusa and ran it at 30/76 with the tall talons and 5S. Did all speed runs one after another only stopping to dig my truck out of the weeds and check speed on my gps. The motor didn't even break 135. So I ordered the 1600 medusa and if anyone wants the mega PM me I'll make them a deal.

what you see is normal imo...
mega motors average efficiency at low and medium portions of the powerband is around 5% lower than the corresponding medusa v2...
peak efficiency is also about 5% lower than medusa v2...

as an example, consider that a 5% efficiency difference means 20watts more heat at 400watts input, whereas a 60mm can is supposed to run 'warm' at 50watts worth of heat dissipation... practically, 5% less efficiency at a similar powerband means 40% more heat...

however, i agree that 15degrees of timing and higher gearing will allow for a better efficiency...


just my 0.02...