NVE Challenger 866
519cfm. The maximum allowable operating vacuum will vary depending on R.P.M., ambient temperature, altitude and time running. The basic principle to keep in mind is - faster R.P.M., higher air temperature and longer run time all equal more heat in the pump. When installing an NVE 866 we recommend a normal R.P.M. of 900. Exhaust gas temperatures read on the supplied thermometer must not exceed 375 degrees F.