5 cell + mamba 25 in a tenth scale for racing?

I have been racing a mamba max 5700 on 6 cell nimh, first in off road stadium truck, and now on carpet in a touring car for the winter. I have never come close to needing the full potential of this system for racing on our slippery dirt track or tight carpet track; 10 cells geared up in a parking lot is fun, but not practicle for racing.
My local track is now allowing lipo in mod class, and no weight restrictions, so I was trying trying to size a motor and battery as light as possible when I found a great planes ammo motor gpmg5195 28x35 mm 2700kv 3.3 oz
11.1-18.5 volt 15amp 277 watt continuos, 30 amp 550 watt burst. @ 18 volt = 48600 so gearing is not a probleme, efficiency should be wonderfull, and the power numbers look way better than the hot 19-turns that do well on these tracks. I normally pull between 2200 and 2800 mah out of my packs in 5 minutes with the 5700. 60min./5min. =12c x 2.8amps(2800mah)=33.6 amps x 7.2 = 242 watts. Plus the 50 oz car would be roughly 10 oz. lighter with new setup. I know some on this forum are scared of five cells on even a mamba max, but the caps are rated at 25 volts on both the mamba 25 and the mamba max. On another forum I read a castle thread supported by castle employees where they very politicaly correct said, the controller is recomended for three cells, but the cap was a good indicator of what the rest of the components are rated for, I think they also said leaving a 20% safety margin would be relatively safe, just no warranty. I am posting this all as a ??? I know the people on this forum have alot of expeirence, but cant find on any forum where this has been tried. My other reason for wanting this is I have a little used mamba 25 (18t racing faded out) and would like to free up my mamba max for a truggy eventualy. Also 5 cell sounds nice in m/t would rather test on little mamba$$ and if all goes well it would be nice to have all my packs universal (small 5s 10th scale; 5s2p in monster)

One more ? do higher voltage lower amp draw setups feel smoother to you guys? My 18t with the 4100 & 3 cell always felt smoother than the 6800 6 cell nimh. Even the 6800 3s geared way down felt pretty good. Very little "turbo lag" and very linear, the 6800 on three cells still took alot of throttle control but it seemed predictable.

[Serum]

The mamba 25 is not suitable for 1/10th cars. At least; i would never use it. the current draw will be much higher. It will be ruined.

Power wise it would be able, but the currentdraw will be much higher. Unless you gear it for 10 mph.

[Serum]

Welcome to the forum!

thank you serum for the quik response. currently i'm pulling less than 250 watts average x .8 for 20% weight reduction = 200watts /17volt (roughly 5s under load)= 11.76 amp average. sounded safe to me, but I have no idea how high this system would spike on acceleration, or how accurate the manufactures motor #s are. I beleive an 8000kv mamba sized motor is rated for atleast 15 amps continuos, but dont know how many amps it actualy pulls in a little car. also what do you think about the driving feel of higher-voltage-low-amp vs lower-voltage-higher-amp setups with similar top speeds. My other basis for this idea is that a 70 amp controller is supposed to be good for 10th on 2s; I'm talking 5s 2.5x the voltage, so only a fraction of the amps needed. 25x2.5=62.5 amps on 2s.
I know this is cutting things close. and appriciate the negative responses also, they may save me an 80 dollar controller.

[Serum]

First; i doubt if the small mamba takes 5S.

Startpower will be way higher. I am pulling a 75-80A current with a light MT under acceleration with an 8 cell pack on a 1350 kv motor. The starting power will be much higher than you expect.

If you want a controller capable of doing it; get a mamba-maxx.

A higher voltage same speed setup will usually result in longer runtimes, cooler motor/controller/batteries. Somehow a high voltage system acts less nervous. (well, high voltage, only have driven a 24 cell monster)

[MetalMan]

Serum, the Mamba 25 has the same voltage limits as the Mamba Max, so if the Mamba Max can take 5s Lipo (several users here has proved it can), then why can't the Mamba 25?

Although the Mamba Max would be better in terms of not pushing the limits (as much).

[jhautz]

I saw someone who ran a Quark Pro-car 33 and a Neu motor in a Losi XXX4-G+ (it was a roller I sold to him) on 3s lipo. That was before the neu motor became ''all the rage'' for us car guys. It was actually the first Neu I ever saw. Not sure what size motor it was. Looked like a 1505 or 1507(it was short). It was the fastest buggy on the track though. The thing was silly and he didn't have any issues with cooling. (I think I might even have a picture of the setup somewhere, I'd have to do some digging though. This was a year or more ago.)

Based on that, I say go for it. but I will note that my Quark33(universal) can take more before thermaling than my mamba 25. I think the heatsink makes a big difference.

If the mamba 25 can take 5s and you are running a very light racing style 1/10 truck or buggy, they arent really much heavier than a losi Mini LST and they run all day on Mamba25. The 5s should actually be less amp load than a 3s setup.

Just my opinion. I say go for it. They only way to know is to try it.:027:

[t-maxxracer32]

what is thermaling mean? heard itused alot

[jhautz]

When the Speed controll overheats and shuts itself down before it destroys itself. Its a safety mechanism built into most speed controlls.

[gixxer]

thermaling is when the speed controll shuts down do to excessive heat.

[t-maxxracer32]

destroys itself or shuts off? lol...

I have seen a mamba 25 with a heat-sink epoxyed on the fets, looks easy just don't know what epoxy to use.
-do the numbers on the motor look reasonable? little airflow in truck compared to airplane, but not looking for monster power, just quick, smooth, and light.
-recomendations for a small light bec?-(so far found atlanta hobby park bec 6.5g (.23 oz.) 6v 1.25 amp cont. 1.5 amp 60 sec.?

-looking for more opinions on higher voltage being smoother? A high kv speed 400 size motor geared down on 3700mah two cells with my M.M. is an easy way to knock of some weight and safer, but then eventual monster/truggy/buggy will be stuck on 4 cell. 2-cell is lighter and cheaper than equal watt/hr 5s. mamba 25 ofsets extra battery weight compared to M.M. + balances out very well in touring car

I dont believe the mamba 25 has thermal protection, but I know how to use a temp gun, as long as it does'nt light off the first time I squeze the trigger. don't want to waste money on a motor and small bec if this is a totaly unusable idea.
I do have a couple old 10c t.p. 2100 packs one 2s and one 3s laying around to test with and the mamba 25.
thinking slightly smaller mah 20c pack if it became permanent. eventual truggy could use 2p for 5min heats add parrallel packs as needed to make the main normaly 10min. around here ocasionaly 30min.

[Serum]

Again, 25A is way too little for a 1/10th, but if you want to burn your controller, i'm not stopping you..