OK, I've now come to the conclusion that either something is wrong with this 80 series muffler or that something is wrong with my LT1 then, lol.

Seriously, I just got off the phone with a rep at Flowmaster and he was basically laughing at me when I told him how dam quiet this cat-back was! And I know from personal experience that the Flowmaster 80-series crossflow mufflers are NOT quiet...Every LT1 I've ever heard has been loud and very deep (you can feel the bass in the rumble). It even sounds fairly loud on the LS1's. Well, not on mine though. STOCK quiet at idle and barely (if any) louder anywhere else. I know they don't flow worth a dam (why I have a cutout), but to say I'm extremely disappointed in the sound is an understatement...

I don't know what else to do other than replace it with something else...Oh well, I love the Hooker cat-back tone (I originally had that and it sounds 100x better than this POS Flowmaster). Plus it flows a lot better too...

But honestly though, does anyone have any suggestions what the problem here is? Because the car certainly isn't quiet when I open up the cutout, lol.

 

Well, you got almost same setup as me, but mine is loud, and has a great tone to it. I got BBK mid length headers, random tech cat(big one, not the one thats in application guide, my car is single cat), and american thunder with the 80. I had an OR y-pipe but put the cat back on cuz it actually felt stronger, better pick-up down low. When i put on Accel 300+ ign box, 9mm wires, BBK 52mm TB, and SLP CAI it got ALOT meaner sounding, bigger difference than cat/no cat. More air in, more out i guess, plus it added this nasty howl from the front fender at WOT, it's great. Also how long have you had it, it seemed like mine got louder as the first few months passed.

 

when i had the stock manifolds and y pipe with cat and the flo, my car was hardly louder than stock, i gutted the cat and it got a little louder then when i put longtubes and a 3" y on it it is actually pretty loud, not loud enough for me but i just assume to drive with open headers all day. only problem with that is the cops, they are not to fond of open headers. go figure.

 

i have shorty headers, and a gutted cat with my flowmaster and when the car is actually running it is VERY loud. It sounds great but its almost too loud. It gets old when you have to crank the stereo to actually hear it.

 

ya know man wut u should do man is just dump it when it comes out after the headerz. then it wuld be real loud man you could do burnouts like vrooom errrrrrrrcchhhh and pickup lotsa girls and stuff.

 

If you open up an 80 series it's made just like a 40 series. The only difference is that there is an exit inside the muffler to the final chamber and it flows to the exit for that side and for the opposite side. Externally there's not much size difference, the 80 series is just a little longer, but inside it's more narrow because of the passage for the opposite side exit. Hope this make sense. For what it's worth the 80 on my 95 has 3'' chrome tips gutted cat and is as loud as any true dual Mustang I've heard w/40's on it. I gutted the cat after the Flow and could only tell a small difference in noise level. I'm changing it though because I'm going to a 3.5 or 4" Mufflex/ Spintech kit. Also you can get an 80 series with a 2.5" inlet. That would quiet it up a bit. I have a friend that I work with and he has a super 40 with 2.25" inlet and dual 2.25" oulets and it's much quieter than a truck at our shop just like it but with a 40 series that has a 3" inlet. More volume more noise!



later,
Vicious

 

I have a magnaflow on a gutted cat, with holes in the muffler Easiest way to be loud. Seriously my fiance can tell Im coming home and Im still like 3 blocks away.

 

Oh, I've long already made my decision now...I'm going to have Speed Inc put on another Hooker cat-back system within the month...

Like I've said, something is definitely not right with my Flowmaster muffler because I've heard the 80 series before on many LT1's and mine sounds NOTHING like they do (it's dog quiet and honestly sounds weaker than stock).

I'll let you all know how the switch turns out once it's put on...But then again, I already know how sweet the Hooker sounds since I've already had it on this car...

 

I first put in the 80 series...it was louder then stock...then I gutted the cats...guess what, even louder...then I put a cam in it (comp cams xtreme) ...now it is ridiculous

It sounds so awesome...when it idles, you can hear the cam and its sooooo deep and sweet sounding. When I open her up to redline, she screams!

 

Cut it open remove the baffles and weld it shut.

 

I HAVE YOUR ANSWER

and the driver side of the flowmaster you have one pipe coming out (tail pipe) right behind that outlet on the flowmaster, cut a hole and put a 3 inch turndown. u can't see it from the back so don't worry about looks. if its too loud you simply take off the pipe and cover the hole. i have true duels now and the flowmaster was way louder and even deeper. hope this helps.

 

Now that the Z is not a daily driver I will be removing the current muffler, removing stock resonator. My exhaust will go from long tube to 3 in ORY to dynomax (no Cats) to twin tips out the rear. Should be louder