Good afternoon
Seeing you are also building a hill climb, it may be that your preferences lean more towards "technical" - challenging - tracks than fast and flowing, so take the suggestions following with the amount of reservation accordingly.
- I find that most people build their first track with too many sharp curves. When they build their 2nd or 3rd track, they tend to make it more freely "flowing" between the corners - even though by now they are a better/more experienced driver.
- Ask yourself who will drive the track - and what classes of car. This may help decide how flowing versus how technical you make the design.
- I have found that the minimum radius to use is about 160mm definitely no tighter than this - ie 320mm diameter. I am now on my 3rd track and my hairpin has radii of 170, 215, 305 and 350mm for the 4 lanes. I WANTED to make it tighter for appearance and to save space, but after having 160, 210 and 260 as the radii of the hairpin on my previous 3 laner, I went more open for practical enjoyment of the design
- Avoid fixed radius corners where possible. Some degree of tightening into the apex, then opening out is generally a nicer "feel" of turn to drive. I have only on fixed radius turn out of 8 on my new track. Even the hairpin works in and out of an apex.
- Ensure you have at least 125mm from the outside lane to any barriers, this is for run-off, and to prevent any sliding cars using the wall as an assistant
- Ignore at least half the advice myself and others give you, or you will never finalise a design
