If V-20 and VX you mean Velociraptor Neo magnet motors, then you are into the electrical power needs of the rest of the cobalt hign power slot world.
When I rebuilt my King, I borrowed a fancy amp meter to test the amp draw of some wing cars. A Grp-27 (sort of a V-20) and the bigger wire opens would register over 40 amp draw each for the nano second of full power pull of the trigger. I ended up with two 8D batteries, a 90 amp power supply to charge them, some canister 2-3 Farad capacitors, and added a second #12 wire to the wiring harness to run the track.
There should be a common 'standard' for wiring drag strips to run high power cars. There isn't, and many tracks look good, but do not fulfill their potential that they could.
1) Big track braid. wide and thick. That is what Gerding uses on his best tracks built in the past several years.
2) Under the track is the wires. If you can afford it, use welding cable. Any track with less than #12 stranded wire is underwired.
3) Each lane must draw power from separate power sources. If not, the first car running gets more power - especially if the track has capacitors in the system. Nanoseconds count.
4) Batteries are cheap high amp power, but building inspectors object to the (unproven) hydrogen outgas explosive possibility in commercial buildings.
5) Power supplies have come a long way in the past 30 years. Never use a big battery charger on a slot car track for power. Better to use RV industry AC/DC convertors like IOTA/Bulldog type units. Even better is the use of high amp 'server power supplies' which need to be wired in series since these are only five volts DC output so three in series can be tuned to get 16 volt DC output with over 300 amp output.
Larry D. Kelley, MA
retired raceway owner... (for now)
race directing around Chicago-land
USRA 2017 member #404
Great Lakes Slot Car Club member
60+ year pin Racing rail/slot cars in America