What causes raspiness to occur in an exhaust? Also, I have a 24" dynomax glasspack resonator that I haven't put on yet. After that is welded in, what sort of losses in hp can I expect? Also, Explain how it works if you know. Thanks.
No horsepower loss. Actually, maybe a fraction of one.
Don't know what rasipness occurs. Possibly because it's a 4 cylinder?? Your guess is as good as mine.
Explain how what works? The resonator? It is filled with fiberglass and that absorbes the sound coming through the pipe.
Do the perforations in the middle just allow some of the air to hit the baffling material?
The exhaust gases are typically flowing too fast to turn down into the holes, except for a very small amount traveling along the surface. The higher frequency (shorter) sound waves wichch are bouncing off the walls of the tubing are small enough to pass through the peforations in the side wall get absorbed by the matting in the body. This only allows the lower (larger/longer) sound waves to continue through the inner core, hence the deeper quieter tone, with very little to no loss of power.
The raspiness is a result of the frequency which the exhaust pulses exit the motor, i.e. every 180 degrees of crank rotation. V6's fire every 120 degrees (even fire) and V8's fire every 90 degrees, the closer the pulses are spaced the less raspy the sound. The poping occures, typically, when very hot unburt fuel (such as suddenly releasing the throttle) reaches the exhaust system where the is more residual oxygen and the fuel ingintes in the exhaust.
Very well informative..thank you very much
