I found some excellent tech articles on the San Diego Rx-7 Club site: http://www.geocities.com/sdrx7_club/technical.html

Underhood Temp

In the article about "Third generation turbo control tubing selection Guide" http://www.geocities.com/sdrx7_club/hosedebate.pdf. In it there is a chart showing under hood temps on at 3rd gen taken at 65 degrees ambient. They're in the ball park with the temps I've measured on mine.

Temp gauge operation

http://www.geocities.com/sdrx7_club/tempgauge.html

This is a really an area of concern... All 3rd gen owners should read this and understand how the temp gauge works! It's more like an idot light than a gauge... :( The article on modifying the gauge (http://us.share.geocities.com/sdrx7_...structions.pdf) charts the tempurature over which the gauge shows "normal".