Can someone please explain to me the power difference for the servos.. You can supply 6.0v 7.4v and now 8.4v to your servo.. now my question is how? I see people putting capacitors between the battery, what’s the point of that? I am confused on how to get the most voltage but don’t want to jack anything up.. please help.

In order to run a servo at a higher voltage the bec has to be able to supply the higher voltage. Check your esc manual. Secondly your servo has to be able to handle the higher higher voltage otherwise you risk the probability of burning it up. The advantages are a faster and stronger servo. Not everyone likes a fast servo. But more torque is always desired. The cap is there to prevent breakouts which happens when the esc demands more power then the battery can deliver. It will cause your car to act very erratically with issues like no steering or you won't be able to accelerate smoothly.

Check out a castle Bec. Pretty much the industry standard, and it's cheap to boot.

Yes thanks for helping a noob... I have a 170s proteck and should I run it at 7.4 or 6.0v?

I would run it at 7.4

If your esc is capable try it on both and see which one you prefer.

So is this a function of the esc? You can choose between the two?

Many ESC's have selectable BEC settings between 6.0V and 7.4V which are most common and nitro drivers typically use a 2S LiPo at 8.4V to power their equipment without a BEC. There are some older ESC's which limit the BEC to 4.8V but those are typically brushed systems.

I recently got an SRT servo that is 0.14 sec/60° @ 6V and I was considering to switch to 7.4V to get 0.12 speed, but after testing at 6V I decided to keep it there, the car turned out to be easier to drive and felt more stable with a slightly slower servo, I had been running a 0.09 servo prior to the switch

SRT SERVOS

*** It's worth noting the following which was posted on the SRT thread:

So a 2cell lipo for nitro provides 8.4v and I would need a neck to get too 7.4v right? Or get a servo that provides a 8.4v?

Generally, most nitro drivers are running servos that support HV... most brands of radios and transponders also support HV @ 8.4V.

I don't think it would be practical to hook up a UBEC for nitro, but that is certainly an option if you need to reduce the voltage to 6V for whatever reason.

Generally speaking, servos that are rated to 7.4V "HV" operation will handle all the way up to 8.4v without a problem, or direct 2s LiPo voltage. Some will run a capacitor as the cap helps with the current loads. When the servo is operating and forcing the wheels to turn it can draw a lot of current suddenly which can in turn cause the pack voltage to sag, which in turn gives the servo less power and can potentially cause a notable drop in performance to some. The capacitor helps smooth out that sudden current draw from the servo so that the performance remains relatively consistent.

castle bec are highly overrated they don't last long.. cap inline with esc and battery are to help voltage sags of bec... depending on servo specs you can get 2x the power or torque to move the front steering.. check specs to see .. i like the turning 20 amp bec has leds on it to let you know n see how many amps its supplying..

0.09 transit speed, and 445 oz-in of torque @ 6.0V
0.07 transit speed, and 549 oz-in of torque @ 7.4V id run at 7.4.. whats it doing and in what?

Agree, I like servo like 0.1 sec with high torque. For fast servo like 0.6, I like to tune down the speed. So, there is no reason for me to have fast servo. In fact, when you race, you don't turn your steering wheel fast.

I don't understand your question.