Feigao 8L or 8XL in e-maxx?

[rcrazy101]

i have an emaxx and was wondering if putting a Feigao 8L with a 9920 speed controller would work good? I would be running 12-14 cells. i'm also looking at the 8XL, i dont know which one would be better. i'm looking to go in the 45-50mph range. thanks

[Finnster]

The 8Xl will not get you 45+mph on 14 cells unless your truck is super light, but I would still go with this motor over the L.

Loads of torque, great accel, plenty of speed (low 38-40ish depending on weight/gearing), and cooler running. Unless you are planning to drive only on street, you will never ever do 50mph offroad. Not long at least until you hit a bump or rock and then 50mph flips and cartwheels get very ugly.

See my vids for an idea what the 8Xl can do in an MT.

[rcrazy101]

so i should use the 8XL motor but can i still use the 9920 speed control? what brushless motor do you think would be the all time best with 14 cells? is that 8XL in your revo?? cause dude that thing is crazy.

[Serum]

8XL all the way.

[Finnster]

Yeah, the 8xl is in both vids linked below, one on 4S, one on 5S. 14cells~=14cells nimh.

The 5S is stupid crazy fast. Too fast really except for street speed runs. You can't drive that fast anywhere else. 4S or 14 cells with an 8XL is really nice. Even a 9XL would be really good, if not a bit better, as off-road I have a hard time even getting upto fullspeed on 4S. A 9xl would be a bit more tq, longer runtime, and a bit cooler. Depending on what driving you plan to do, I woudl choose between these. AAngel has a vid a few threads down showing an 8ight-T w/ a 9XL (on 4S IIRC.) Still really fast. Its easy to get hungup on #'s and topspeed, but really you want acceleration and cool running temps. Having to stop every 5 min bc your motor is too hot gets lame fast.

Also, if you have not bought the ESC yet, I would get a Mamba Max& ubec over the 9920. Cheaper, way more programmable and great customer service should it ever fry. BK is having probs to say the least, and getting an esc repaired is a long (6mos) and expensive process. CC will fix the esc for any reason for $50, and turn around is ~2-3wks. I've used one for ~9mos w/o issue on 4S, and many others here use them as well.

[rcrazy101]

if i ran lipos wat shoudl i run (size)?

[rcrazy101]

can i still run the 9920 speed controller with the 8XL?

[rcrazy101]

wat is a ubec? and wat does it do?
and where can i get a mamba max cheap?

[rcrazy101]

wat mamba max esc should i use?

[KYLL_E-MAXX]

There's only one mamba max esc. Each motor uses the same one.
http://www2.towerhobbies.com/cgi-bin...&I=LXNKT9&P=ML

[Finnster]

RCM has the MM esc as well.

Do not use the MM motors however! Some people make the mistake of this and burn things up. You have a 7700 system, so you can see the motor is small (a S or small can motor in fact.) You are looking at an XL (or extra long) motor. Get these here as well, and some 5mm pinions while you are at it. The heatsink is also a good idea so the motor can never pops off in a crash.

The ESC works fine w/ 14 cells or 4S, but you must disable the onboard BEC (battery eliminator circuit) and use and external one instead. They build up too much heat otherwise. This is true with the 9920 or pretty much any ESC for that matter, so its a wash. Mike has a fine UBEC for $40, but cheaper ones can be found for ~$15 as well on airplane/heli sites (sry mike.) In all you are looking at ~$280, but it will kick ass.

You disable the BEC by removing the center wire from the RX connector (must do this!). You then tap the UBEC off the batt leads then. This reduces the 14V+ down to 6V, and plug this into the "batt" terminal on your reciever. Sounds a bit complicated, but really its easy. One word of note tho, I've had some trouble with glitching using various ubecs when I've used less than a 2.4ghz radio (like a fasst or spektrum). Others have had success tho. Try to keep Rx/ant/& wires as far as possible from motor as it creates lots of elec noise => glitching. That's why I would get the $15 one. If you do have probs, then you just use a Rx pack like the nitro guys do. Not as elegant, but works very well.

[rcrazy101]

so if i use this UBEC

http://cgi.ebay.com/ws/eBayISAPI.dll...tchlink:top:us

and my MM speed control i should be set for a 8XL motor

[BrianG]

In short: Yes. :)

Hmm, I might pick one of these up to bench test...

[rcrazy101]

when running the 8xl on 14cells what size pinion do you think i should use?

[BrianG]

That I can't help with as I don't have (or ever had) a Maxx...