feigao 6xl or 3s of 8xl on 4s
 

What would be the better option in an e-revo (gorillamaxx conversion):
feigao 6xl with 3s lipo (aprrox. 30.000rpm)?
or feigao 8xl with 4 s lipo (approx. 30.000rpm)?

Both configurations will reach approx. 30.000rpm, so in theory they would be able to reach the same speed.

A 3s lipo configuration would be slightly cheaper and lighter, but on the other hand the 6xl will draw more amps, right?

Can anyone tell me what de advantages/disadvantages are of both configurations?

Look at it this way, if you need, say 1000w to get the performance you want, the 3s/6xl setup will have to pull more current to get this than the 4s/8xl setup. So, I would go for the 4s setup - the weight gain from 3s to 4s is all but negligible.

Also, with higher current, the loaded kv is lower, so your actual loaded motor speed will be less, and might not get exactly the same top speed. Not to mention the inefficiencies dealing with high currents.

5S and 9xl would be even better...

thanks for your reply. makes sense (though I don't know what loaded kv is...)

but what if I have more than enough current avaliable, lets say 150amps constant and 230 amps burst. With 11.1V I would have > 1500w available and 2300w availabale in bursts...???

would the points you mentioned still matter?

Power = I x I * R

More current more loss i.e more heat in ESC and Motor... You don't want to be pulling 150amps constant even if your batteries are rated for it. You'd drain a pack in a couple of mins.

Feigao's are not that effecient relative to to Medusa and Neu... Heat and RPMs equal burnt windings and cracked rotors...

What battery are you going to use to provide those specs? Plus, what esc are you going to use? Not many setups are going to work well on 3s in a heavy vehicle. 4s is the min, and 5s is much better.

My guess is that they are looking to use a 30C 5000 or 25c 6000

A 6xl on those batteries will tax them hard, unless it is geared for 30mph.

The type of battteries I am looking at right now are 2 4s1p 4250mah packs rated at 18-27c (hyperion lcx). If I connect them in parallel I get 4s2p, 8500mah, 153 to 230 amps?

Please correct me if I'm wrong. But that shouldn't that be sufficient?

I'm going to use a MMM. And with a 8xl looking for 40mph.

I would go either 5s w/9xL or 6s w/10xL...my preference would be the 6s marriage will be the most effiecent and coolest running

just get 2 of those 11.1v packs and put them in series, mamba monster/125b and your set!

A pair of mid-range 3s lipos and the cooler running 10xl would be much better than any 3s 6XL setup- you would have alot more run time too.

Yep, what neil said is correct.

thanks guys.
so looking at 6s lipo with a 10xl now. how much runtime will i get out of a 5000mah 30-60c pack?

Alot! That is a big battery, if you gear for 40mph, you should easily get 30mins, maybe more.

Now I've been using the speedcalculator alot, and I noticed the medusa afterburner v2.

If I compare the 60mm 1600rpm from medusa with the feigao 10xl, theoretically I can reach the same speeds but the medusa has more axle torque&hp.
Feigao 10xl on 6s: 4.93 ft-lbs & 1465.2 watts (2 HP)
Medusa 1600 on 6s: 7.25 ft-lbs& 2064.6 watts (2.8 HP)

I've read there's a 70mm version of the medusa coming, but it looks like the 60mm should be good enough. As I consider the price difference reasonable(NEU is too expensive for me), wouldn't the medusa 60mm be a better option over a feigao xl?

I have been very happy with my v2 60mm 1500kv medusa. I run it on 6s in an 1/8 buggy. It does run cooler than an xl motor. It is similar in size to a neu 1512. Not sure if it is identical to a neu, but it looks very similar.

I would expect the medusa to have better number than a fiegao considering they are twice as expensive I have never ran one since I am content with a Neu

Well, I guess i'll try the medusa then. My e-revo wil weigh approx. 11lbs with proline 40series dirt hawgs.

As I'm still building it, I'll wait a bit untill its ready for the motor. Maybe by then the 70mm medusa will be out or castle creations motor for the monster max.

Thanks for the support.