|
On gas engines, straight pipes can cause a loss in horse power, actually need to dyno to find the HP curve. Things that straight pipes cause, as previously mentioned are a lean burn, which leads to a richening of the fuel system to compensate. Bluing of straight pipes is more likely than not over richening of the fuel and actually continuing to burn into the pipe. Gold on a gas is good, blue aint bad (rich), pink is bad (lean). If someone wrapped an inch or so of bare copper wire around the pipes near the head, will dissipate much of any heat that discolors the pipe, so won't have a color to go by. Running lean wreaks havoc on engines. Straight pipes with no back pressure have a tendency to cause a cooler backside of the valve and guide, which is good for the stem and guide, not good for the valve when the face is considerably hotter than the backside for long periods of time. Mufflers too can be both good and bad. They do cause some restriction (back pressure) which both robs and increases HP, depending on the design. Some of those "louvers" are so large that they act like cheese graters and cause so much turbulance that they maximize back pressure and restrict exhaust, causing exhaust to linger inside of the cylinder and combustion chamber, contaminating the fuel/air mixture of the intake stroke. Ever pulled an intake manifold and found exhaust soot in the runners? But many an engine has been dyno'd and shown a loss of HP and torque after went straight piped too. If you're running a diesel, or a turbo, big and unrestrictive is good. Put in the ear plugs and let it fly. Those puller guys or race car guys do a lot of maintenance that most don't have the time or will to do. By the way, gas or diesel? Guessing has no turbo. You didn't say. Mark
|
