Something like this may help slightly.

Extra_Cool.jpg


Not tried it myself so unsure as to how much it would help if any......
 
A Cupra intercooler or a Forge one would help. Also you can get replacement intake manifold gaskets that insulate the cylinder head better.
 
You asked if warm weather can affect the boost, and yea it can. But if you have a flat spot in 3rd gear, maybe there is a problem with the map. Have you fitted a new recirculating valve like a Forge 007P? You could be loosing boost thru the standard valve. Which remap did you go for?
 
Do the Pikey wheel arch mod made a big difference for me in warmer weather

take the wheel arch liner out

get a drill and a 23mm hole cutter

go to homebase or bnq and get a 9x6 louvre vent, spray it black, mark it out on the arch liner then drill a few tidy holes and rivet the grille onto the arch liner
 
Do the Pikey wheel arch mod made a big difference for me in warmer weather

take the wheel arch liner out

get a drill and a 23mm hole cutter

go to homebase or bnq and get a 9x6 louvre vent, spray it black, mark it out on the arch liner then drill a few tidy holes and rivet the grille onto the arch liner
sounds good that might have a go later when i get this problem sorted