Exhaust.. Simple rules to follow
Building an exhaust systems is not the "black art" some may think it is, here are some simple rules for you to follow.........
FIRST - Since an engine is an air pump, much of its power making is based on how easily air can get into and out of the cylinder. Restrictions to this inward and outward flow are called pumping losses.
EXHAUST SYSTEM - The pipping that directs the engine's exhaust stream from the exhaust manifold to the tailpipe. To get there, it must first pass through the catalytic converter and the muffler and out the back of the car.
To produce the most power, your exhaust should have the least amount of restriction to the exhaust flow.
Restrictions hamper the burned exhaust gases from getting out of your engine, exhaust left in the cylinder is mixed with the fresh intake air/fuel mix. This is called charge dilution.
Charge dilution causes a loss of power, pumping losses. With greater restrictions, back pressure is generated, making the engine work a lot harder in pumping the exhaust out of the cylinders.
MUFFLER - The straight through designs (STD) are best. What that means is there is little to no restriction in exhaust gas flow. The longer the (STD) muffler the quieter it is, not more restrictive. Old school mufflers, like some glass packs, and lovered piping should be avoided. These cause back pressure, inturn causing charge dilution.
TIPS - Large tips on todays exhaust systems are for looks only. Some are resonator type tips, these restrict flow as they quiet the exhaust. You can tell them apart by looking at them. The resonator tip will have a perferated insert.
COLLECTORS - These are the 'Y' pipes exhaust makers talk about. A "y" pipe is used to split or put together exhaust/header pipes. I would not use a true Y pipe, instead use a converge collector, I say this because of restriction. A converging collector has the inlet/output pipes against each other in a straight line. They are much harder to make, but the straighter the way is for the gasses to travel the faster they will move.
PIPING - The straighter and smoother the pipe the faster the gas moves. Any bends in the pipe will slow the gasses. Types of bends are critical. Mandrel bends are best, becuase the diameter of the pipe through the bend is the same allthe way through the radius. Some bends will have a corrigated section on the inside of the bend, and that adds restriction.
HOPE THIS HELPS...
Bigger pipe diameter is not always better..... But, I'll leave that for another day....I have to work sometime ;)
Never drive or ride faster than your guardian angel can fly.