Ring Racers Custom Map - MKDS Test Circle 

Well, it's not a straight port of it, but it is very similar.
Technically, this would be the first released RR custom race map, using a lot of workarounds, as the mapping tools aren't fully out yet, though you can use Ultimate Zone Builder with the base SRB2 UDMF config with a bit of elbow grease, therefore, this map was made with an edited version of the SRB2 UDMF config with elements from the RR UDMF config in the source code repository from about a year ago.
Ring Racers got a massive upgrade in stuff that map makers can do, even though we don't have the official map tools yet. ACS in of itself seems really powerful and I can't wait for maps to utilize it to its' full potential.
Download Dr. Robotnik's Ring Racers: kartkrew.org
Download: file.garden/ZEHSglmmckD7qQR7/HY_TestCircle.wad
Please add to the link above.