Vary LED brightness with throttle input...
 

I have a Redcat Racing Blackout XTE. I am working on a project to 3D print a new body to make it look like an Octane from Rocket League. I need to know how to make a pair of LED light bars glow brighter as I give throttle on the transmitter like the boosters in the game glow when you drive forward. Any idea for how to do this? It would really complete the look later on. (Note: transmitter, battery, and receiver are all standard to the XTE, no aftermarket parts)

You'd likely need to dim the LEDs by PWM rather than direct current input. I suspect you'd need some kind of module or micro-controller to take the throttle signal as an input & output the required PWM signal.

Get a cheap low power brushed ESC

I think you need LEDs.

For quick and dirty y cable the esc to a second brushed esc and you can drive LED's from there. Test the voltage and use an LED resistor calculator to determine the correct resistos to put inline

If you're ambitious, checkout Spark Fun or Adafruit for one of their smaller Arduino based boards. There is an Arduino library out there (I've used it in the past) that will allow you to read the RX output, which you could then used to control the PWM output to the LED's.

Do you have specific light bars in mind? I've got an existing module that could likely be programmed to do what you want, it's good for up to 300mA as-is.

As a side project, I've mucked around with a custom light bar (I have visions for this for an updated F1 safety car) which can run any combination of colours etc:

Roelof has my vote. I did it with a PIC to do the same for a fan. there are also 2 or 3 position relays that are controlled like an aux channel. 3 different resistor values will get you 3 levels.

This is my little module that I just tweaked to do PWM output from the throttle instead of blinking. Weighs about 4g
https://cimg0.ibsrv.net/gimg/www.rct...71e9a4e916.jpg

Stuck it in the touring car and hooked up three LED brake lights. It's not calibrated, but shows the effect easily enough:

Phil.