Just lookin at adding air intake to my 99 911 cab. I was leaning toward K&N kit. Any suggestions on the best fit for performance and not having to re-tune??

 

Also take a look at the Fab Speed Cold Air Intake System. What ever you do stay away from oiled filters. Even light oiling can contaminate the MAFS, giving warning light problems.
Fab Speed system probably gives upto 10bhp improvement, based on my installation.
Regards Big Bob

 

I have a K&N air flow kit and it works grea. I see some difference.