HELP HERE ! Mamba maxx and feigao 9xl setup slow as hell!!! - RC-Monster Forums

I've just got my mamba maxx and fiegao 9xl and tried it without it installed in my truck cause i wanted to feel and hear the power. Well it was a big dissapointment cause a mabuchi motor would go faster!!! Is there anything wrong im doing here? My battery is a 2s 4000mah. Should i use two of those? I need some help here cause i was told that this setup would kick an hv maxx. Could have it been initial setup of esc? tried to update it thru usb still same power output on engine!!! Help

Dafni · 11.09.2006, 08:32 AM

Well, a 9XL on 2S won't give you much rpm. This motor feels more at home on 5S.
I guess your intention was to use it on 4S :032:

Try it on 2 2S packs in series... twice the voltage will give you twice the rpm. But don't rev it up too much without load!

Another heads up: even two of those 4000mAh Batts won't do the trick in an EMaxx in the long run. Their discharge rate might be put to its limit, and the packs will suffer over time.

Hope this helps
DAF

11.09.2006, 08:34 AM

But the MM said max is 3s lipo's? right? So what would you recommend?

11.09.2006, 08:45 AM

I'm a racer at the local track and our run times usally last 5 min per race. I hardly use the truck for bashing!

Dafni · 11.09.2006, 08:46 AM

See, the 9XL has a KV of 1667. That's 1667rpm per volt. And you typically want to have around 30-35'000rpm on a BL motor in a car. So you'll need around 20 volts for a 9XL to work in the efficient range. Less might work too, but already 4S is not ideal for this motor. Opinions differ, though. I'm speaking from my own experience here, mind you.

The MM is rated for 3S max, but as is common knowledge now, it can take 4S easily if you use an external BEC and a fan on it. Even reports of the MM taking 5S without problems pop up here and there. It's up to you. Just make sure you have the BEC disabled.

Please refer to the other threads on the MM here. This has been discussed before.

One member here, CrazyJr, runs a 9XL on a MM on 4S, and seems to like it alot.

DAF

Serum · 11.09.2006, 02:03 PM

2S on the 9XL for a monstertruck?

That's asking for speed related problems.. that motor needs more volts.

coolhandcountry · 11.09.2006, 02:27 PM

Crazy jr runs on 12 cells which is slower than 4s. He is real happy with it.
He likes it more than the hv.

glassdoctor · 11.09.2006, 02:55 PM

4s will be plenty but it will have to be geared tall... run in 2nd gear. There will be plenty of power you just have to put it to work....

neweuser · 11.09.2006, 03:10 PM

You can run 2x 2s2p in series and gear up. you're kv won't be that high, but you can do it. The motor may run a tad on the warm side though, at least mine did. It ran better on 5s lipo. Like Daf said, the comfort zone for that motor is around 30-35,000 rpm. You can calculate the rpm's with this equation. volt x kv = rpm