Medusa 2S or 3S for CRT.5?
 

Hey All,

I now have two e-crt.5s.

CRT.5 #1 - is my wife's that is built with a stock ofna chassis and buggy wheels, and run it with a Mamba Side Winder and 4600 motor. I kept it as light as possible and don't have heat issues running on 2S maxamps 4200 batts.

CRT.5 #2 - is my original crt.5 with a RCM chassis, my Revo shock upgrade, truck wheels and Novak GTB/6.5 system. It has a lot of aluminum upgrades and is a lot heavier than the other. I run it on 4800 or 5000 hardpack 2S batts.

My beefed up crt.5 is ready for more motor to go with it's mini-monster look. I'm trying to decide between a (Medusa 50mm 5900kv on 2S) or a (Medusa 50mm 3300kv on 3S).

5900 on 2S (95amp cont, 115amp peak)
Pro - would be better because I could share lipos with my 10th scale race vehicles
Con - Will probably run hotter and be harder on batts due to the higher amp draw

3300 on 3S (75amp cont, 90amp peak)
Pro - probably run cooler and be easier on batts plus may have more punch
Cons - have to buy 2 new batts just for this setup

What do you think?

3300 on 2 or 3s - I have it and it gears up very well on 2s and after a full pack motor is not hot at all...

I was going through the same debate in my head. I ended up choosing the 3300kv on 3s. I had to buy new batteries as well. I was running a Lehner basic xl 4200 on 2s and it wasn't bad (~35mph, 20min run times), but I wanted more power. This set-up performs much better.

What gearing and lipos are you running on 2s?

I'm begginning to think 3300 on 2s for the momment and then buy some 3s lipos in the near future. What 3s lipos are you using?

I will check but I think 18/46 on proline 30's.

It is perfect top speed for track and runs ice cold - a full pack at flat out in grass does nothing to it.

Neu energy 3s 3900 25C lipos.

I have 3s A123 cells which come into my crt.5.

So may be to much for the 4800 and to low for the 3300?

Got pics of both your crt.5's go-ride??? Looking for some ideas when I start my build.

I tried a medusa 3300 on 2s in the .5 and if you gear it up is actually suprising how well it works (I regularly have a Neu 1509 in there). You can expect there to be some losses in acceleration though. I used some Zippy-H 4300's on there and they didn't seem to heat up too much more. They are much older now though so I would expect them to have a harder time. I tend to go for lower kv even if i don't increase the voltage (just increase gearing). Everything seems to run cooler that way. I am currently running the medusa 3300 in my lazer on 2s geared waaay up and it runs all day long on the 4300's and everything stays very cool.
GO-RIDE we need to get together sometime to run.

Hey Ren,

I'm in the works of overhauling the electronics of my crt.5. I recently bought: (2) Rhino 3S 4000mah lipos, a Mamba Max esc, and a Medusa 50mm 3300kv motor. I'm working on a new battery holder for the Rhinos and the rest will got together in about 1 hr. Hopefully, I won't regret the much greater power of the 3S Medusa over my 2S Novak 6.5 (1/10th). Somehow I doubt it.

My wife was actually asking me today when we could go drive. I found a used Spektrum DX2.0 for her car, so now we have two complete systems.

Sounds like you have a very good wife.

Yeah she's petty cool. I pretty much make her do my hobbies so I don't feel guilty about having fun without her. The last couple of weekends we spent in the deserts of Utah riding MX.

Lucky. :great:

Can you give us an update on your Medusa 3300 performance on 2S and 3s (speeds, temps, gearing runtime)?

I'm not sure if I should get the 3300 and gear it up (for use on the loads of 2s packs I already have) or if I should step up to the 4800 (may limit my ability to go to 3s later)

Do you have the V2 version of the Medusa?

3300 on 2s gears up fine...

^ Agreed. I have a 36-50-4800kv on stand by, but I think I'm going to put that into a touring car now, since the 3300kv seems to do great on 2s when geared tall.

on 3s (geared 16/46), the 36-50-3300kv is about as much speed as I can handle without crashing every time. It has me grinning from ear to ear.

I've been running the 3300 on 3S with both a 14T and 12T. It is a beast at the track and jumps any triple from the inside of the corner. No having to take the wide line. It pretty much puts the fear into any mod 10th scale. The motor doesn't get hot even with the 14T and truck tires, but my MM has been getting up to 160. I think the MM has a problem as it been cogging lately, so I'm sending it off to Castle.

Ride - Couple of things on the MM - I find they do benefit from an UBEC from 3s and above and an extra cap (such as novak hv) really does lower temps

When it gets back from Castle I think I'll try the UBEC. Kinda bums me out as I hate having all sorts of extra wires with things like UBECs and extra caps. Right now it is cogging so bad that it will not start without a push and then runs very hot. Something has gone wrong. :cry:

Check your connections - One might have gone bad...