EMAXX Dual Servos or Single Servo BIG JOE TIRES
 

I have an EMAXX brushless with Big Joes that my servos just can't seem to keep up. I am running the Tactic TSX57 on both sides and I've never really been able to get the speed or power that I'm looking for.

Here are the servo specs:
4.8V 6.0V
Torque: 176 oz-in (12.7 kg-cm) 188 oz-in (13.5 kg-cm)
Speed: 0.23 sec/60° 0.20 sec/60°
Dimensions: 1.6 x 0.8 x1.5" (40 x 20 x 38mm)
Weight: 2.1 oz (58 g)

I'm going to be running a Mamba Monster 2 which i understand has an internal BEC?

So two questions.
1)Do I need to upgrade both servos, if so, what is the most cost effective way to go with the 3.8" tires? Or can I get away with one highly efficient servo to power it?

2) Do I still need an external BEC or will the Internal BEC of the Monster 2 be enough?

Thanks for your help!

Before getting to the servos have a look at your servo saver. The 3903/5/8 Emaxx servo saver is commonly pretty loose hurting performance. Make sure you have the stronger black spring (chrome is weaker) installed. If you have the black installed and the saver is flexing when just turnig the wheels on the ground consider doing the dual servo saver mod. When I had a 3908 with a single Hitec (333oz) it would flex the saver so much it wasn't funny. Unfortunately the dual saver mod is the only way I know of to stiffen up the saver, which they (or the aftermarket) would've made it adjustable.

Your current servos have decent torque but they are slow. I personally recommend under .18/sec, more like .15/sec would be ideal. According to the servo's ratings you should have enough torque though. I still run the same Hitec 333oz servo in my heavier LST with Trenchers and it throws the wheels around like nothing. The flexy servo saver was the limitation in my EMaxx

As far as Bec is concerned the MMM2 should be able to handle it. The adjustable Bec voltage definitely helps and make sure you turn up the voltage. Factory default is 5.1 volts, for your 6.0 volt servos I'd set it to 6.2 volts. This way when voltage drops under load the servos will still see as close to 6.0 volts as possible. I'd also be really tempted to try cranking up the voltage even further and see if performance improves. I would think the servos could handle 6.5 volts and it might increase performance quite a bit.

I run genesis tires and wheels which are the biggest I know of and a decent savox with >225oz of torque whips them around no prob

Hey I'm running 2 savox 0231 waterproof. 208oz @6.0 and running the cc bec that I have turned up to 6.0v. The Rx and servos are rated at 6.0V so are you saying that it would be okay to adjust that bec to 6.2V? And doing so wound not blew either the Rx or servos?

I will not say "6.2v won't damage your servo or Rx". I will say that electronic components are usually able to take a little more than their ratings. I say this because servos and Rx are powered by batteries and battery voltage can vary so a little wiggle room has to be built in. So .2 of a volt shouldn't blow anything rated for 6.0 but you take that chance.

Cheap upgrade
 

Head over to Valuehobby.com.and get two Power HD 1501MG's and there direct drop ins. These are 200+ oz servos with decent speed. But I used a pair in my brushless Summit as the 2075's weren't cutting it at low speeds.
These have been my go to budget servo for years. I've never been disappointed and I've referred many people who purchased them and they all have thanked me. You can't beat em!