When i first got my car together I simply ran over to AZ to pick up a cone filter with a 4" inlet.... el cheapo spectre worked great. Tested the car with the filter on and off and found no difference in power, so i said screw it i will run it. I find out now that these cheap filters can implode and destroy a turbocharger. I haven't seen it mentioned here so i figured i would share.

 

cause4panic:
Thanks for the warning. It appears to be an inverted cone (double cone?) filter. I'm guessing the inner cone rips off or the outer begins collapsing and allows the inner cone to contact the impeller. There are 4" x 9" single cone filters, I suppose they wouldn't be able to collapse enough to enter the machinery.

 

love the car.

 

That could turn very ugly if not noted. Thanks!