Restrictions In The Stock Muffler?

Titan XE · 09-28-2005, 08:38 AM

Last week I swapped out the stock muffler for an aftermarket one. (Has anyone changed just the muffler and not the whole cat back?) I had about 2700+ miles on the truck and kept the original muffler as a spare. Looking at the removed stock muffler I see two distinct purple/bluish bands completely around it. One measures an average of 4" out from one end of the muffler. This is the oppostite end of the welded hanger. The other purple/bluish band is right around the muffler's center. It measure at least 5" and in some spots larger. They are obvious burn marks. For the rest of the muffler to have it's perfect original uniform color, there must be some restrictions inside the muffler to cause those burn marks. I'm not calling it a defect but I can see a few extra HP being lost here at least. I swapped it out for sound only. The mechanic said the new one would give an extra HP or two. After seeing the bands on the original I believe it.

Sammy Sandbag · 09-28-2005, 10:17 AM

Havock tore one apart to see: Stock Muffler Guts

buzzkillwill · 09-28-2005, 10:21 AM

That looks like carp!!

Not his cutting job, the internal compartments. What's all that-stuff he took out of there, the shiny stuff?

Man, I've gotta get a better exhaust system...

Sammy Sandbag · 09-28-2005, 10:23 AM

It's sound absorbtion material, either steel wool or a fiber or a mix of both. All your Magnaflow, Banks, Dynomax, type mufflers use the same material.

Titan XE · 09-28-2005, 10:36 AM

Thanks for the cool link Sammy! My middle band matches his except on the far right of the muffler. You can barely see his second burn band as mine is more visible. He may have swapped his out earlier than 2700 miles. Mine may also be more prominate from a few 200+ mile hauls at higher than average speeds.

scr38 · 09-28-2005, 10:51 AM

Quote:

Originally Posted by Sammy Sandbag

It's sound absorbtion material, either steel wool or a fiber or a mix of both. All your Magnaflow, Banks, Dynomax, type mufflers use the same material.

I don't know about the other makers, but Gibson does not use any packing. See attachment.

Sammy Sandbag · 09-28-2005, 02:43 PM

That's why I didn't mention them. If it's a chambered or deflection style muffler like Flowmaster then it won't use any absorbtion material.

PHOEBISIS · 09-28-2005, 03:06 PM

There is some hybrid potential in that sound noise-gas velocity that the muffler turns into heat by banging itself against steel wool aand baffles.
Turbochargers mine that energy to make more hp(turbos can be pretty quiet,and they can have lighter smaller,less restrictive mufflers).The hope with Turbos(on spark motors) was that you could get the same power from a 4 cyl as an 8 cyl and this would drop weight and improve mpg from the wt loss and less internal friction.Unfortunately,it just never worked out that way-for a lot of reasons-detonation-octane-lag-heat-reliability-6 and 8 cyl motors going all aluminum,and becoming more efficient,lighter etc.It does work that way on Diesels-they don't have the detonation and problems wiht lean burn that spark engines have.They also run cooler because of the huge excess of intake air.
My point-finally-some Brit Company has developed a tiny turbine driven by exhaust gases.It drives an alternator that charges the Hybrid battery.With this Hybrids could now get improved HY mpg to match their city mpg.I wish I was a more adept fabricator.I would loved to attempt some sort of add on kit for the Titan.I had kinda figured that the Hybrids were just going to get small mpg increases from here on out.If they manage to use this they will get another biggish bump.Sorry to run on.Charlie