( Where are you getting your fresh air input to your
  heat muff?  Any other suggestions?)

  Chat

On my ES the source for the heat muff is in the baffling above and behind #1 cyl.  It goes from there to the right muff then to the left muff and on to the heat/overboard valve (the two muffs are in series).
I fly in the low to mid teens and always have plenty of heat.

Leon Smith
LNCE N63LS (200 hrs)l