Based on the relative insensitivity of the Renesis to backpressure, a turbo was installed on the test stand Renesis.  I had previously installed the same stock 1988 RX7 turbo on the test stand 13B and observed a large penalty in efficiency at cruise power levels.  As a result, I had lost interest in a turbo option.  At the rotary gathering this fall, Bobby expressed an interest in how the Renesis would respond to a turbo.  So some data was collected in this regard.  Those present at the rotary gathering may recognize the plot of data that is attached.  It showed the power generated with a 13B normally aspirated (NA, red), supercharged (SC, black), and turbocharged (TC, lighter blue).  Data from the normally aspirated (NA, green) and turbocharged (TC, darker blue) Renesis has been added to this plot.  The results seem remarkable in that there appears to be no penalty at cruise power for the turbo installation on the Renesis other than weight and complexity.

The data by no means represents an extensive study, but the difference in response of the Renesis to the turbo compared to the 13B seems worthy of reporting.  Field elevation here is 7200 ft with DA normally above 8000 ft which limits normally aspirated MAP to 23" Hg at WOT.  An intercooler was installed on the test stand for both engines.  No attempt to boost the Renesis above 30" MAP was made.  It is also unlikely that the turbo tested would be the best match for this application.  Any thoughts on identifying an appropriate turbo would be welcome.