I learned something about mufflers today

[Exodus_2pt0]

Hell, i run basically open headers on the Corvair and Firehawk. My truck is the normal one with a Thrush chambered muffler lol.

I put those thrush mufflers on almost every truck that comes in asking for a louder exhaust. Can't beat the price.

[Deathtoll]

Found this little tidbit and it does seem to explain my experience.

Internal combustion engines produce exhaust gases in uneven flows. As a result of the pulsing production of exhaust gases through the exhaust system, vibration is transferred to the vehicle. Exhaust vibration is produced through sound vibration and mechanical vibration. While complete removal of these vibrations is not possible as along as the engine is running, significant reductions can be made to allow the vehicle cabin occupants to ride it relative comfort.

The first step was to replace/ check your muffler.

I drove the car a bit hard on my way to work and its by no means quiet. Is exactly how I like it.. Loud when pushed but hush hush when I want to drive normal. seems as if the S52 will not be contained :)

[JasonC]

I put those thrush mufflers on almost every truck that comes in asking for a louder exhaust. Can't beat the price.

I'm pleased with it. Eventhough its on a 4.3, it has a deeper tone to it at idle and isn't raspy like most 6cyls at higher RPMs.

[ELVA164]

This is incorrect, AFAIK. Back pressure isn't a good thing. It's a bad thing. The notion that some back pressure is good comes from the good ole days of carbs. When you put a free flowing exhaust on an old carbed motor without adjusting for it, the increased flow will cause the car to run leaner, running a risk of burned valves, ect.

You want as little back pressure as possible, particularly for high rpm power. What you don't want is slow exhaust gas velocity. Too large a pipe slows the exhaust gasses, which has numerous negative effects on performance.

Oh, my fault. All our race cars are carbed and respond exactly like this. I didn't realize things changed with injection/electronics/etc. Oops :oops:

[Deathtoll]

It is my firm belief that 95% of all mufflers that make a louder than stock noise do absolutley nothing for gaining horsepower or torque. Muffler only.