its two different mufflers.

The spinn tech is a better quality looking muffler.. it look like a freaking robot from that tv show where fight each other.

The flow master is well a flow master... they seem to last a few years and then you get another one... also know as blowmaster because they seem to blow out... brad has a 8.1L truck and it melted the baffles in the his flow master in 30K miles... with you towing a lot im not sure it would last that long... guess thats why they are "cheap" mufflers.

this is a cold start with the flow master, granted i have long tube headers, "high flow" cats which makes it louder..
http://www.youtube.com/watch?v=6duId...er_profilepage

this why i had to take it off! after the cam swap
http://www.youtube.com/watch?v=nSYHj...er_profilepage

then when the blower went on it got about 50 louder than that lol..


Ill see if i have a clip of the spinn tech... on the truck... its louder than stock but not omg loud.. then when you hammer the it sounds a lot like chamberd side pipes on my vette.

 

Yeah see what it would cost to ship to 99013 and you can PM me with a total and a payment method that would be great. Also did you notice any low end power loss with the spintech? because that is the main part of the power that I dont want to lose.

Thanks
Tim

 

ok anyone else have any Ideas here on a muffler? I have been told here in town that the only one to put on this truck is a Flo-Pro, but they want 350 for the thing at all the local muffler shops. Do any of you have any other Ideas?

 

I too am considering the flo pro HD oval for my 05 8.1 Burb. The 2500 says it is like stock, both inside and out, but I read a post by a guy running a muffler shop somewhere, that had a clip of the 2500 sound and it was nice. May have been on gmfs forum. Anyhow, teh 2506 looks interesting too. i want mild sound, that doesn't kill me inside like the magnaflow I had on my 5.3 PU.

 

Well I needed to do something so I broke down and went with the FLO-PRO 2505. I have to say that there is not much difference in sound from the stock one, it has just a touch of a deeper tone and right around 1500 RPM's is about the only place you can barely hear it in the cab. you can sure tell it flows better than the one that came from the factory because it is a lot more snappy now and pulls the hills without a single downshift, where before it would downshift at least one hole.

One interesting thing though, the stock muffler is a dual out, but the bank on the driver side is completly blocked. They make it look like a dual out but in reality it is only a single with a pipe welded to it. now I have a true dual system and I think that is where I notice the most difference.

 

thanks. that is interesting about the blocked off side. but, the flo pro website shows the 2505 to be "moderate" in sound outside the truck. that is why I was considering the 2506, because their site shows less sound. But, if it is hardly noticeable on the one you have, and it is the 2505- I would think the 2500 or 2506 is no louder than stock. That is not what I am looking for. How much did they charge ya and what part of the country are you in?

 

yes, the stock mufler is a dual in, dual out muffler, but 1 of the exits is a dummy pipe that doesnt exit anywhere.

I used to think that this was blocked off on the 6.0 HD's to provide a tad more backpressure for teh smaller engine as the 8.1 and 6.0 HD trucks use the same dual 3" exhaust.

Apparently the dummy pipe is present on both engines. It must be for some sort of exhaust resonace tuning or something.

peace
Hog

 

Yeah the shop I dealt with said it was for resonance. I used the 2505 and it is no louder in the cab than stock and at idle it is not really louder than stock it just has a deeper tone. Towing a stock trailer full of cattle up a 6% grade today with the passenger window down and right next to the Jersey barrier it is just a deeper tone but no bark to it really. I like it and it seems to flow better. and I dont have any backfires like the rotted out stocker.

I am in Washington state up by spokane. and I got it for 200 installed

 

Jus put some longtube magnaflow glass packs on my 8.1 doesnt resonate not raspy at all but i have longtube headers and no cats.wish i had a sound clip

 

Its deeper sounding than the clip above