Good point, I thought the same about some of the compiled flow rate data I've seen posted up before. None of it states the inlet/outlet locations on the mufflers they used, at least that I'm aware of.

 

I had a Flowmaster cat-back on my old 95 Formula. It sounded amazing.

I have a cutout with the stock muffler on my 99 Trans Am, but if the stock muffler ever rusts out or if I need to replace it whatever reason, it will be the Flowmaster just for the sound. Can always open cutout for max performance.

 

Hey darkvader, do you mind posting a sound clip of your cutout? I am thinking about getting one.

 

Given your location, all you have to pass is a computer test. A tune and you are golden.

 

Specific location is in Saint Charles, MO. I was told by several shops that a LT/Cat/tune setup would still fail emissions in Saint Charles county...any truth to that?

 

go with the Texas speed rumbler. I just got one and love it, deeper sounding than the lm1 and it screams WOT. Just be careful if you decide to get a new y pipe, spend the money on high flow cats unless you can put up with a little rasp.

 

i think the flowmaster muffler is fine. i think it sounds good until the manifolds are replaced with long tubes, then it is too loud and raspy. i have an ory and 80 series welded into the stock muffler location. it sounds good, but 2-3k rpm sounds terrible.

whoever said the 80 series flows worse than stock, here is some food for thought: the car trapped 88 in the 1/8 with a lid and that muffler. full weight 99 m6 car. i highly doubt it would go faster with the stock muffler. i added the ory and it actually slowed the car down. it doesn't 1/8 mph like it did before, but it backhalfs better and still traps almost the exact same 1/4wise.

my only complaint about the muffler is that it's too loud and raspy with long tubes and mine (after 6 years, 65k miles) is falling apart.

 

Agreed!! Flowmaster is not as bad as teh internet makes it out to be. I agree with longtubes it gets raspy between 2-3k. My best time is 12.2 w/ slp lid, ported tb, 1.85 rockers, hooker lt's, stock stall, flowmaster cb, 3.73's and 315-35-17 toyo tq dr's. Only reason Im changing it is because of rasp and my hooker lt's are rusted bad. So full kooks header/true dual exhaust setup is on order.

 

I think we are missing the mark here. The Flowmaster is an improvement over stock. It is however, the most restrictive of the aftermarket crossflow options. Therefore, for the same money you can do beeter in the flow department. As you add more mods you will not choke as much horsepower with other cat-backs. Sound is personal preference.

 

I bought my car with flowmasters on it and I love the way it sounds but I dont notice any difference from stock at all. Dyno'd 313 with them on which leaves a little to be desired.

 

Bull ****. Show me a test where a chambered (I'm talking a 40 or 80 series) out flowed a bullet style muffler. Impossible, period.
I understand all about scavenging effects of exhaust, the way the merge/muffler and everything works together.

Why then do all the cars for all out performance run a bullet style muffler instead of a chambered muffler.

I have seen plenty of dynos on both side.





With that said... Stop lumping Flowmaster mufflers together like there is only one. A 1 chamber race muffler will outflow 90% of the mufflers being discussed any day of the week.
An 80 series and a 1 chamber are COMPLETELY different mufflers in all aspects.
You can't just say, "Flowmaster mufflers suck for performance".

 

i think the muffler sounded way better when the car had cats on it. adding an ory made the car obnoxious.

i am, however, doing my duty to make the car loud. the manifolds and 80 series are coming off for a set of tsp 1 7/8" long tubes and a 3.5" dynatech split flow bullet, ran over the axle, Yd and out the back (dual 3"). that should be...really obnoxious. i am curious what it will sound like going out the back. we shall see.

 

Where did you go? Im in the same area and running LT's, ORY, and a cutout and have no issues passing. They don't do the sniffer test around here, they just plug into your computer, so as long as your tuned you shouldn't have any issues.

 

My first Camaro had an 80 series with PaceSetter LT's and no cat...Sounded absolutely beefy!! I had no rasp/// 3" all the way..

I just bought another camaro and I wanted the FM sound but I dont like the crossflow design (even though I have never seen dyno results to back that debate) I went with a Super 44 3" inlet dual 2.5" same side exit (most aggressive sounding 2 chamber) their is a sticky where you can place it like a 80 series and buy some wrap around piping for the dual look.... once I got it under there, I realized you could mount reversed with the inlet twoards the front of the car and and the duals out the back into CME...... The Super 44 sounds BA!! PM me if you want the link to the design of a 2 chamber FM set up..........