Currently my 305 TPI Trans am has no exhaust past the cat. I bought it that way and am finally getting around to fixing it. I actually like the way it sounds now, but it drones so much at highway speed that it gets annoying and I'd like to tone it down a bit.

I picked up a flowmaster muffler and am considering doing shorty headers and a high flow cat or cat delete. I know that flowmasters are pretty loud and the headers are going to make it even louder... is it likely that the car will be even louder after the install than than it is now? :/

 

It will sound great. It will probably be a lil louder. I run 3 in, cat delete out to a Flowmaster and I love the way it sounds. Had same setup on my last 3rd gen except I ran a Borla muffler. Liked it even better honestly.

 

I've heard certain flowmaster's can have that "drone" sound at highway speeds, do a search on here to find out. As long as you run the exhaust out past the rear axle you should be fine. Most of your problem now can be attributed to the fact that the exhaust ends at the Cat.

 

I have Shorty headers, full 2 1/2" exhaust no cat to a magnaflow and is not much louder than stock. way quieter than my other one with stock exhaust and a cherry bomb

 

I just added the 3" Loudmouth1 exhaust to my Formy- you KNOW when I arrive! Stock 305 (so far) and headers, cat-deleted...

 

I have an 11:1 compression LT1 with a big cam, long tubes, no cats, and this is what my muffler looks like on the inside. And my car is pretty quiet for what it is. Certainly more quiet then your open exhaust Y-pipe.



When my LT1 was stock, with shorties, and a the SLP 2 on the Left cat-back below at idle it was as quiet as a stock car. No joke. And the exhaust is a straight through design.

I had no drone, and the car was quiet as a mouse, even at full song it wasn't that loud.

 

i really do not like flowmasters. everyone has them and every car that has them sounds like a mustang plus they drone.

spend money on a hooker, magnaflow, borla or SLP system, you will be much happier

 

Headers vs Manifolds. Not any louder, not really. Cat-converters quiet a car down. The Muffler quiets the car down. If you are running sans any exhaust, even a stock manifold/Y is going to be loud as hell.

Compression makes noise. Removing the cat makes noise. Aftermarket exhausts make more noise, some more than others. However, if you have a stock engine, almost none of these exhausts will make your car turn into a top fuel dragster.

I will pass along a vote for a Hooker Aerochamber, its quiet at idle, no drone at all, and at full song it sounds glorious.

I am partial to the SLP 2otL Cat-back.

If you have a Flowmaster, they are okay, but aren't the best flowing, and sound is an subjective measurement, some like the noise, others like me hate it. I prefer my cars to scream at the top end, which you just can't get with a flowmaster chambered muffler.

SLP 2otL Cat-back, stock w/Full bolt-ons.



Versus, same stuff but with Heads/Cammed.

 

I'm not real happy with this video but it is as close as I can find for the Flowmaster 80 Series muffler. The car is idling fast so its most likely in closed loop. Sounds better once the idle settles some.
Definitely the Flowmaster sound.
I have the Flowmaster 3in. American Thunder cat back with the 80 series muffler and love it.
=

 

Headers won't make it "louder".

You will HATE HATE HATE HATE HATE that Blowmaster after about 3 days. It's SO COOL at first, for maybe 10 minutes or so; but it doesn't take long to get on your nerves.

I made the mistake of putting one on my car not long after they first came out. Late 80s, early 90s somewhere. I. COULD. NOT. STAND. IT. Worst POS I have ever put on my poor innocent car, bar none. It sounded like I was dragging around a 55-gallon drum in a shopping cart everywhere I went. Ended up cutting it off, and I gave it to one of my littlest bro's friends (my littlest bro is 14 yrs younger than me) who put it on his LG4 car. (gotta do something to not be at the bottom of the pile, right??) AFAIK it didn't last more than a month on his car either.

"Loud" exhaust is like Corvettes: they're for people with ... ummm .... masculine insecurity. The kind of people that are making Pfizer and Lilly rich w Viagra and Cialis: it doesn't work, so you try to impress .... someone ... with a substitute. If you need that to feel like you're "somebody", you're ALREADY in trouble; the "loud" exhaust is just gonna make it worse. All it does is make everybody around you hate you for being an a$$hole and disturbing their peace. (when they're with a lady and NOT having that ... insecurity ... thing going on, and she doesn't want to be disturbed any more than YOU do at that moment)

I have the Hooker cat-back on my car ATM. Still too loud for my taste, but AHELLUVALOT better than that damn Slowmaster EVER thought about being. At least it doesn't **** off everybody around me, like, the people I have to live with all day every day for decades at a time.

 

sofakingdom,
I like your style. Your one of a kind and I always enjoy reading what you have to say......




Well since you have been driving it with out a muffler and not pissed any one off yet ......
If you can use clamps to hold it all together you can try different mufflers and not be committed . You can change them out with out to much work.

Since you have the Flowmaster 80 Series ( it is the cross flow 80 series right ? )you can try it.


I also like the Hooker Areochamber muffler but do not care for the Hooker tail pipes with the dual exit. Looks good on some cars though.
Here's a suggestion , keep the tail pipes/tips just a bit under the rear bumper cover. Especially if there not rolled on the end.
Mine were razor sharp so I cut mine back a full 6in. You can still see them from the rear and I like that.
There 3in. diameter just like the rest of it.

 

Wow... because you don't like Flowmaster according to you that makes hundreds of thousands of people who do like Flowmasters insecure in their "masculinity", it makes them "a$$holes", and they have a need to "impress" someone. Really..

 

If the shoe fits...

I think we mighta just found one.

 

dmccain, don't take it personally, this guy is a professional bedtime story teller.

 

Has anyone who claims flow master 'drone too much' are ' too loud' ever driven a car with true dual exhaust? It's insanely loud. I go from my buddies 75 nova to my 88 with it's insanely loud and annoying 80series and yet it sounds very quiet to me, not loud enough?

I guess it's a tomato tomata thing

 

Basically, ANY exhaust that has tips that direct the exhaust out from underneath the car and past the bumper will be fairly quiet inside the car. This is because no sound waves will bounce off the floorboard and pavement underneath the car.

An exhaust with hidden tips that use turn downs behind the bumper will be louder than a normal exhaust that has tips that extend past the bumper.

And if your exhaust dumps before the axle? Its going to be loud as hell inside the car.

Then you get into the various mufflers, and if you look at the picture of the SLP 2otL I posted its nothing but a straight through design that takes a single 3" center inlet, and splits it between two resonator cores with 2.5" outlets. Such an exhaust shouldn't be as quiet as it is.

My 2otL is pretty darn quiet. Right up until about 3000-3500rpm, then the exhaust seems to transition to a higher pitch. In that transition period of a 500rpm or so I get a harley like blat-blat exhaust note, almost like a baffle has come loose. Then after that it is much smoother. But seeing as how the cam doesn't actually come on until 4000rpm or so it could be a function of the cam lobe design.

At full song I'm sure you can hear my LT1 quite a ways away.

 

It's hard to say. It will be "different." But louder or quieter is tough to venture.

Headers are a mixed bag when it comes to how much louder a car will be. Headers on a stock exhaust are pretty much indistinguishable from manifolds. Headers on a car with GMMG, Borla with open valve, or SLP Loudmouth will be much louder.

Flowmasters are fairly loud by themselves. They're not the loudest exhaust. But they're louder than most. In my case, I went from no cat and Flowmaster to GMMG and a cat......It was louder with the cat and the GMMG. Stock manifolds on both setups.

I will tell you this though. The Flowmaster did have that classic muscle car sound. And it was fine for summertime driving, rare weekend cruising. But it would get annoying in daily driving use. I found that going to car shows, my car sounded like 99% of the other cars there. That's part of the reason I wanted to go with something different.

The Flowmaster did drone though. Somewhere around 2100 RPM if memory serves me correct. I have zero drone with the GMMG. Honestly, I'd look at getting an SLP, Magnaflow, or Hooker catback in terms of getting something that sounds good, sounds louder than stock, and is easy enough to live with in constant use.

Getting a full exhaust will make the car sound better. But louder? I don't know.

 

Here's what I did to my 87 350. Hooker headers,3" pipes,no cat,a stock (yes a factory stock)muffler and a elec. 3" exhaust cutout that fits perfectly under the rear seat area. This way I can have quiet driving or I can open the cutout to whatever level of loudness I want. And the nice thing is that it go's from open to close in 5 seconds. Which comes in handy if there are police around.