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Wanting better flow without being very loud.

G

greyavy

New Member
Joined
Jul 15, 2004
Messages
6
Location
Lubbock, TX
Looking to put a better catback on an 04 5.3 and wondering what a good brand would be, if i didn't want it to be very loud. don't really care about sound. Just mainly want it to flow better than stock. what do you recommend? Any sound clips?
 
check out muffman's posts about the Flow master 70 series setup....

Not a kit but a good local shop should be able to do it ...and per muffman it gives best perfomance with least interior drone....

Ps welcome to the club
 
The new Magnaflow SUV/Truck muffler has little to none interior resonance, and exterior is clean sounding. My tip is out the side, and I know you get a little more sound when you go straight back.

Check out www.magnaflow.com
 
Question for muffman or anyother exaust guys. how does the FM 70 compare to the magnaflow? the magnaflow wide open looks like a glass pack, is it? how much should I expect to pay for a FM 70? thanks
 
Tator,

$104.00 is a good price considering list price is around $160.00, and Flowmaster just had a 12.5% increase in price in May.

Blue Av, no, a Magnaflow isn't like a glass pack. The only comparison is that both are straight through mufflers.

The best Magnaflow to be used on the 5.3L AV is the 5 x 11 x 22 inch cased Magnaflow.
 
I installed the Flowmaster 50 w/delta flow, sounds great not to loud and very little noise in the cab. $110.00 muffler, $100.00 to install, $60.00 ss tips

Gary

 
Blue Av,

I did not recommend the Magnaflow, I just told you the case size to use if you want one for the Av. I prefer the sound of the 70 series with the 5.3L motor and the noticable lack of resonation in the cab.

Are you going to change out the stock tailpipe? Or just change the muffler.
 
I plan to keep it stock unless you can tell me of some major HP gain from doing otherwise. I was thinking of just removing my old muffler and welding in the new.
 
Doesn't GM recommend or sell Corsa products as direct replacement for their stock exhaust?
 
Yeah, Corsa is endorsed and approved by GM, only because they struck a deal, not becaues Corsa is any better than a multitude of other choices.

Blue, if you are limiting yourself to changing the muffler only, and your only criteria is horsepower, and not sound quality or lack of resonation, use the Magnaflow #12579. Magnaflow's entire cat back kit with this muffler gives you roughly 10.5 RWHP increase (at about 5200 rpms), so the muffler alone is probably worth 8-9 RWHP.

All you have to do is hack off the "Y" at the front of the tailpipe, cut out the old muffler, build a short 3-inch section at the front of the tailpipe and weld the new muffler in.

 
I followed Muffman's advice and installed the FlowMaster 70 series (#530722) with a 3 inch inlet and dual 2.25 inch outlets. It has a nice growl on startup and when you get on it. No resonation whatsoever. Right after I had the system installed I took a 2,000 mile road trip with my family and I got no complaints at all (except for the standard: "Are we there yet? and Can we stop soon? I have to go to the bathroom.)
 

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I had the FM 70 installed with a 3 1/2 inch ss tip for $200.00 plus tax. It sounds purrrrrrrfect!!
 
muffman said:
Blue, if you are limiting yourself to changing the muffler only, and your only criteria is horsepower, and not sound quality or lack of resonation, use the Magnaflow #12579. Magnaflow's entire cat back kit with this muffler gives you roughly 10.5 RWHP increase (at about 5200 rpms), so the muffler alone is probably worth 8-9 RWHP.
Click to expand...

Magnaflow #14579 is the exact same thing, but in Stainless Steel rather than aluminized steel. Since the rest of the factory exhaust system is SS (I think), the 14579 might be a better choice.
 
Number one, the #14579 is a "wrapped" stainless, it is not 16 guage as the aluminized one is. Additionally, both mufflers have a lifetime warranty, so why the heck would you pay more for the stainless unit.

Just because the AV has 409 stainless components from the factory, doesn't mean you have to stay with like metals in the system. That's crazy, what.....you think you are going to get electrolysis? LOL :eek:
 
Gator,

Sorry, forgot to answer your question. Gibson is the most "removed" system that we see in my stores. Most complaints are for resonation, and quality of sound.

Soooo, I don't like Gibson at all, and in my experience, it's an inferior product.
 
muffman said:
Gator,

Sorry, forgot to answer your question. Gibson is the most "removed" system that we see in my stores. Most complaints are for resonation, and quality of sound.

Soooo, I don't like Gibson at all, and in my experience, it's an inferior product.
Click to expand...
Muffman,
I have the Gibson single/side system. I would like to change just the muffler and retain the front and rear Gibson 3" pipes. The Gibson muffler has a 24" case with a 30" overall length. I was looking for a direct fit replacement muffler with the same dimensions (something with a little more aggressive tone). I was on Magnaflow's web site and found a couple mufflers with the same dimensions (#13959, #13742, and #12279). Any idea how these mufflers would sound on a 5.3 Avalanche? I am not commited to any particular brand --------- I'm just interested in the 30" length so I can simply replace the muffler. Thanks------
 
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