January 18: Today was much colder outside. 22 deg F on the ground, and in the teens in the air. Usually I would not go out in these low temps, but wanted to get in another test. This time I opened the intake hole in the engine baffle to 100% open. - Taxiing I measured over 70 deg. - Climbing out the OAT was 18 deg F. Saw 72 deg. - I tried closing the flapper valve on the firewall and the temperature dropped to 50 F. So you can't get more heat by restricting the flow at the firewall valve. - Level at 3,000', 2,900 rpm, OAT 18 F: temp was 60 deg. Today was a colder day, so hard to compare to the previous flight, But I think the next test will be to neck down the intake to where it was on the previous test, and then start playing with the setups downstream.