There will always be a slight amount going to defroster,as it is part of the default to the HVAC system... More than that,I suspect one (or,more) of the blending doors is not closing all the way...
Winner 2001 Road Course (prep. class) Detroit,MI
Winner 2006 Drag race (SS class) Indianapolis,IN
Quickest event reaction time .013sec. (final-round)
Class Winner 2014 Charlotte,NC. 2016 NOLA car shows
Winner 2019 Road Course (prep.class) Pittsbugh,PA