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then why do most of the guys on here that have half what i have but have the 4". what is the reasoning?
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Over compensation for a small penis? Ok, I am just kidding! /ubbthreads/images/graemlins/biggrin.gif
Personally, I think it's the bigger is better mentality. IMHO, the 3.5" gives a broader more usable powerband, and what it barely gives up at the top end peak, it more than makes up for with the "area under the curve power" in the rest of the powerband. Also, the outlet of your turbo where it connects to the exhaust pipe is just barely larger than 3" so why would you need the giant step to 4"? Also, Gale Banks has stated that he prefers 3.5" downpipes but he sells a 4" because of people having the affore mentioned "bigger is better mentality". And another thing, many of these big turbo setup's such as the H2E, W.O.P. Quick Spool, & BDP H2E hybrid all utilize 3.5" downpipes. If these Big air breather's can work with a 3.5" DP, then our measly turbo sure as heck can.