4" Exhaust

[Matt0matic]

My MagnaFlow system isn't a true 4" system, the downpipe is 3.5", but it has the hangers welded on and seemed to me to be a very good buy for the money; it was ~200 shipped from Summit.

[kingairc90c]

K&N have high flow but rather poor particulate retention until they get a little dirty then they filter better. AFE makes a better filter in my opinion. just my 2 cents.

[CTcummins24V]

Love my 4" turbo back exhaust! Had it straight piped for a while but it was a little loud for daily use, put the straight through muffler on that came with the kit and noticed a little loss of flow, but still sounds mean at WOT and has that awesome CUMMINS idle! This third gen that lives on my road always drives by with his 5" and has me wondering about going bigger in the future though...