I do not see a whole lot of data showing how filter directly on turbo may hurt performance due to the possible turbulence caused by the filter. However I do remember having put a mesh over my turbo once and hurting spool up. Does any one have any experience or actual data as to whether having a pipe before the turbo is beneficial (to straighten out flow before the turbo)?

 

My buddy made a few round 10 ish when he added a tube on his evo... But that could of just been moving from the heat, or a better/ cleaner filter . Maybe enough change in temp or where the airs being pulled...or like you said reducing turbulence

 

gona be alot of different factors involved, no one solution for all.