World formula gearing

What rpm does a wf clutch completely engage? What rpm would be too low for the slowest turn on a track?

The only curves I can find suggests you would set it around 5k RPM. Then gear for best lap. This often will result in you hitting rev limiter on the longer straights

5k??? The limiter is at 7100

I know it seems high. With LO206, and rev limiter of 6100 most common is two black springs at our track. That is 3800. When I ran KT100 we engaged above 9k. I think it was about 9400 and geared for something in the 14k+ on the straight. That was 20 years ago, so memory may be off, but LO206 I am confident about