Tomorrow morning im going to start mesuring for the new exhaust system. I have the layout in mind, but i still havent found much in the way of hard evidance on the benifits of a crossover pipe. If anything I would use an H pipe. What, besides an equal taste of exhaust from each bank for the 02, would be the main benifit of the H pipe?

 

An H pipe does not affect the 02 sensor. The way an H pipe works is it helps equalize the pressures inside the exhaust pipes. As you know your exhaust pulsates with each exaust stroke of each cylinder. An H or X pipe will equalize the pulses and help your engine to "Scavange" air. Have you ever looked at the strokes of an engine and seen were inbetween the exhaust and the intake stroke both valves are open at the same time momentarilly?The reason why engines do this is for a scavanging affect of air. the flow of the burnt gases through the exhaust valve causes a vacuum to help pull air and gas into the cylinder. An x pipe helps equalize the pulses increasing the scavanging affect...That's why hemi's were so effeciant, and why imports use the hemi head. The placement of the valves in the hemispherical head allows for the most effective scavanging affect possible. This also explains why import andmodern moduler motors are able to achieve 90 to close to 100 percent volumetric effiecency.This explains why equal length headers increase power and torque, and also equal length piping for the exhaust. If you look into it you can find some headers were they connect the "companion cylinders" together to increase the scavanging affect even more...i forget what these headers are called..sorry....most of these kind of headers are costum and very very expensive...this is the type of headers indy cars use i believe. sorry for the long post...but i hope this makes you want to install the x or h pipe...trust me it'll will increase the power and torque and make your exhuast sound alot better....
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