Headers, Back Pressure, and Deleting Catalytic Converters
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Published 2023-08-19
-- Backpressure happens when you force the fluid to change its velocity multiple times downstream in the exhaust system.
-- The purpose of a longtube header is to use otherwise wasted exhaust gas energy to lower the pressure at the collector and allow flow to become possible through the usage of valve overlap. When the header is not resonance tuned, this venturi equilibrium technique becomes quite valuable and has a lot in common with a manometer.
-- Deleting catalytic converters isn't necessary in many applications, so don't do it. The reality is, we're lucky to have gasoline at all. It's 200-Million year old goo that we get out of the ground with drill that's literally over a mile long, and distill that goo into some combination of chemicals that behaves in a partially predictable way. The catalytic converter is part of how we stabilize this process, and deleting them isn't always practical. The longer you make the header primary, the worse the catalytic converters will work. In most cases, you'd be better off using smaller tires or different gears. The only time you can delete a catalytic converter is when you're using a fuel that's homogeneous like Ethanol, Methanol, or Dimethyl Ether. E85 is not homogeneous. For example, alkane hydrocarbons require a stoichiometric ratio of near 15:1, but alkene hydrocarbons or benzyl groups function better with a 13:1 ratio which constitutes a 15% margin of error. By comparison, a homogeneous chemical like fuel grade methanol will be 98% pure, which gives you a 2% margin of error and allows you to have thermodynamic parameters better tailored to the fuel as well. We're fortunate to have petroleum, so let's make the most of what we have left so we can optimize our technology for whatever hydrocarbon we replace petroleum with.
-- Take care, thanks for watching, and use this information wisely.
All Comments (2)
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Very informative, thanks for this!
