does that cure the problem ? i read that some suggest an external BEC which doesnt make sense to me if you can up the voltage of the one in the esc.

thanks for the help.

Amp draw is the problem, not voltage. You can have brownouts with 5 volt or 6 volt settings.

1258's can draw 5 amps at 6 volts stalled out.
Most servos draw 3 to 4 at stall

Edit:
4 amps at 4.8 volts... hmmm, I see where others may not have had a problem with their rx8 if at a lower volt setting

But then your also not getting the most out of your servo at less than 6 volt anyway.

I refuse to use savox or spectrum products because of these types of issues. Airtronics ftw.

+1. ^
I turned the bec all the way up on my old mmp. Didn't make any difference at all.

Hmmm I run both savox and spectrum and only time I had an issue was when I ran it with my mmp. For the prices you can get a good used savox I will def. keep using them. However best servo I own and would like to buy more are the radiopost servo's............

This ^^^

Everyone blames the Savox servos, but IMHO, it's the MMP piece of dogshit that's the problem.

Well that is kinda the issue. Savox, MMP and SPektrum are probably the most common amongst the non pros. And together they are an issue. I have also heard the Savox give issues to the Tekins and LRP's also.

Thankfully I haven't had the issue of the Savox Brownout but I have helped a few people that have. A glitch bust should be all that is needed.
I am running mine off of an LRP SXX TC spec v2. I know the LRP's have a higher amp internal BEC than most other manufacturers so maybe this is why I haven't seen the issue.
I run a Savox in one truck only right now, just as a tester from Savox and I do like it. All of my other servo's I use are the AE 1015's. Great power, great speed, great price.

Well the savox are not the most efficient servos. They just have a nice price point.

Nope. It's the Savox. That being said I still run Savox in all my vehicles. It's even an issue with my rx8, however all I need is a cap to make things work, unlike mmp I had to have a external bec. I ran a few different servos with my mmp and spectrum and had no probs. but take any one of those 3 items out of the equation and pribs solved. I battled this and trouble shooted for over a year.

Agreed mmp do suck tho.... Haha

couldnt you just bypass the esc's bec and draw directly from your main lipo ?

That's kinda what the external bec does ... So yes.

Yeah, the worst part about it is that I had a replacement case at home for the airtronics that broke. I just needed toget through the night.
Turned out, I didn't get farther than the first turn in the main and pulled off the track to get out of the way.

LMFAO: as I read this thread, the flashing banner at the bottom of the page is for Savox Servos!