for example a cold air intake.
technically, yes. hotter air means that the molecules are more spread out, colder air means the molecules are closer together. So for a given volume of air, say 5 cubic inches, the colder air will have more molecules in it.
No. It it just a denser air charge, allowing more fuel to be added for more energy expended during combustion.
Copper is the top choice among homeowners and Tucson and Phoenix plumbers for about 85 percent of new home construction. But as the price of copper continues to rise, plastic pipes are becoming more popular (Plastic tubing PVC (polyvinyl chloride), ABS (acrylonitrile-butadiene-styrene) PE (polyethylene) and PEX (cross-linked polyethylene.)
colder air does not equal higher compression. colder air equals air that is more dense. the only thing that will change compression is lowering the compression distance by means of reducing the combustion chamber size by milling the head, installing a thinner head gasket, raising the piston height, increasing the stroke. You can also change the dynamic compression by changing the camshaft duration to a shorter duration by closing the exhaust valve earlier to reduce overlap. This is a technique used by camshaft manufacturers and engine builders actually to lower the compression by leaving the exhaust valve open longer to bleed off compression.
Copper is better in my opinion because it lasts longer, but most houses these days are built with plastic piping because it's cheaper. Also, plastic piping is easier to install because copper has to be soldered together, whereas plastic just needs PVC cement.
