With regard to temps, this is what I did some time ago. Originally went for the K & N Typhoon but the inlet air temps were horrible (I use ScanGuage II). So, simply, I removed the K & N filter box, modified the pipe work and reinstalled the original filter box but managed to retain the lower K & N pipe and inlet. I can't remember the temp differences now as itwas over 2 years ago but it definitely improved intake temps both at idle and when driving.