I'll comment about this specifically for Airtreks or Evos. I've been using K&N drop in since I got the Airtrek 5 years ago. Never tried open pod before, and now itchy handed.
i just read through the fiat forum n come across this topic. i didnt know fiat can give a good fight to the skyline. but personally , i dun too agree. he boosted his car till 1.1 0 1.2 bar. n i dun know how many bars...