Originally Posted by JeepGuy

This seems like a great way to race the Z with less risk than some of the wheel-to-wheel series. I don't think I'd be comfortable putting a brand new 30k car on a track with a dozen other cars. Leave that to the guys in spec e30 and 944s, at least there if you f-up your body it's cheap and easy to replace.

Since the Redline site didn't give too much info, here's the other links I was looking at when checking this out.
Time attack - Wikipedia, the free encyclopedia
NASA Time Trial