How is it possible that exhausts get broken in and sound better after awhile. I hear so much of this on this forum. someone plx explain

 

If they're glass packs yes, a classic example is the old "cherry bombs" often sold in a 32 gal. trashcan at the local NAPA back in the day - they tend to blow out and burn down the insulation (fiberglass - hence glasspack). This usually happens at a fairly quick pace depending how hard you are on your car. This burndown/out makes the exhaust louder, not necessarily better sounding. Over time this can be a bad thing as it will decrease backpressure and can lead to a leaner (hotter cylinder temps) A/F mixture in some types of vehicles depending on the ignition/fuel system.



If the muffler system is similar to Flowmaster's Mustang American Thunder Kit for example, this is an all metal design; then the answer is no, not alot..... There is nothing to "burn away" as it were. Note, that over an extended period of time (typically years) even the metal interior baffles of the all metal exaust will burn away and the exaust will be louder....



Regards,
Kevin

 

The OEM manual GT mufflers contain some fiberglass matting in a resonator tube inside the muffler, according to a person that modified their stock mufflers here at TMS.

 

thanks

 

I do know my flowmasters got louder, I'm not sure how but they seem a bunch louder after a couple weeks.

 

I agree. My Flows got louder as well...

 

How is that??? i have Flows also and did notice a slight change. the flows are nothin but metal. I think we need a scientist to figure this one out

 

Stock cats come wrapped with a fiber material not sure if its fiber galss or not
on the flows it might be a loose fitting allowing exhaust to escape?
just a thought because nothing else really makes sense, so check the fittings