As many may have noticed these cars don't have the speed to conquer even a small commercial 1/24 track.
1st, is that they need more speed. Bank's are nearly impossible and short straights are topped out a 1/3 through.
2nd, the guide design isn't very good.
3rd, grip is a problem. At top speed the thin urethanes don't have it.
4th, gear mesh is almost always bad because these old brittle nylon gears are just horrible.
#1: I changed to taller gearing to change this. A cox crown works great.
#2: I cut off the one side of guide and drilled a hole through that, the lead wire thing, braid and the other side. I then screwed everything together. It works very well
#3: I found a pair of 1/32 sized 5/40 wheels with soft molded on silicone's. The main thing is that you should find a wider tire. The originals are soft enough but in the curves they don't have enough surface area on the track. The wheels I found are also smaller diameter which should help with speed.
#4: The Cox gear fixes this greatly. Works so well.
Here are some pics of the modifications
P.S. doing this with the black chassis doesn't work as the axle to motor mount length is too short.