I just ordered a new exhaust. Just some Magnaflow 14851's. I plan on a custom pipe job, but after reading a post ona civic forum (http://www.hondacivicforum.com/m_39893/tm.htm ) about the truth and myths of backpressure, im not sure what i should or shouldnt remove from my current OEM setup. At first I was gonna remove the resonator and maybe the pre-muffler and run 2.25" all the way into a Y instead of the crimped Y that is on the stock setup and 2.25" to the mufflers. Anyone gotany good ideas or expriences?

 

Simple...less backpressure is good. A good exhaust system creats a scavanging effect in the manifold/header because of pressure differentials in the tubes...but that is different than backpressure. For the cleanest exhaust go with around 2.25 to 2.5 for your N/A engine, leave the cat, but remove the rest. The other parts are there for tone and volume control, which i assume you aren't concerned with. Try to have the piping as straight as possible, and when it has to curve or bend, use mandrel bends that are as large a radius as possible. Although you already have mufflers, the straight-through perforated core designs have the smoothest exhaust flow.

 

Go with a 2.5" all the way....I would also look into purchasing a Pre-Fabricated Y-Pipe...MagnaFlow makes a Real Nice peice which I am actually using on my setup.

 

I'm thinking about removing a muff and pipe & capping the Y. See what kind of torque gain I get and make people think it's a 4 cy l[sm=badbadbad.gif]