1998_trans_am_ls1

iTrader: (5)

who has Flowmaster American thunder on there car ? most people dont like it i have it on my 1998 trans am and i really like it

1998_trans_am_ls1

iTrader: (5)

you are telling me no one on here has Flowmaster american thunder because i know some of you do ?

INMY01TA

iTrader: (1)

Had one like 6 years ago. Sucked IMO. Sounds weak on the LS1 to me. Better on LT1 or Mustang.

01BlackCamaroSS

iTrader: (1)

i had it 2 years ago on my ss it sounds horrible i went with the LM and never lucked back

Masochist

iTrader: (1)

I didn't necessarily not like it on my '02 WS6, it was just that I KNEW it was an inferior piece, I've seen evidence for it not to mention the overwhelming opinion of this site is that F-Body + Flowmaster = Divorce waiting to happen.

With headers it sounds pretty good, but I say just get another cat-back(Borla, LM, Hooker... etc) or go duals.

ChocoTaco369

I used to have it on my 3.4L V6 Firebird. It was the only time I ever heard a V6 sound decent, at least under 3,000 rpms. They do the job as a sound mod.

TheSilverOne

iTrader: (22)

80 series muffler

Cumbias

not many people have it because its been shown that the 80s series muffler that comes with is restrictive compared to other cat-backs. Good sound though. .

streetassasin

iTrader: (30)

I had one on my old third gen and it sounded ok

waldershrek

iTrader: (1)

I had a 80 series crossflow muffler on my third gen stroker also and it sounded good. I don't know about the flow but I'm told compared to other manufacturers it is not very good on an LS1.

Steve Gunn

slightly better than stock...it flows great when your cut out is wide open.

JScamaro

iTrader: (6)

I used to have one on my LT1 back in the day. Knowing what I know now I would not have bought it and went with a better flowing exhaust.

plaf713

iTrader: (8)

i like the sound, its not raspy compared to other catbacks, especially when you put a cam on your car

andrew69_04

iTrader: (148)

I had one for about a month. on a stock car it sounds good. Its a well built system and it looks nice. When i put my mids and ORY on i couldnt take it, that stupid 80 series sounded like a dam tin can about 2-3K RPM. I would go with a magnaflow,hooker setup if your not wanting to spend a **** ton on the over rated borla.

SOMbitch

iTrader: (8)

I just took an 80 series FM off last week (came on car) and went with a Hooker 3" catback with a Hooker Aeroflow muffler and could feel a slight SOTP difference. UNC Charlotte (heart of NASCAR country) did a study on flow characteristics of mufflers (posted on LS1.com) and the FM 40 series (same as 80's) were quite restrictive. The Hooker tesed really well which is one reason I went with it (price another).

67SS&99SS

iTrader: (7)

When I first got my car in 01, I was impatient and didn't research on exhaust. I had flowmaster muffers on several other vehicles, and thought I would get relatively the same sound, but I was wrong. I had the american thunder catback on the car along with an SLP y-pipe for about 8 months. I absolutely hated it. There was basically no volume increase with the exhaust and very little tone change. After being introduced to the concept of true duals, I never looked back. All it took was one ride in my friends Z with longtubes, true duals with one chambers dumped. My car got the same setup a few months later and I couldn't have been happier. However, I gave the catback to my uncle to put on his LT1 Z28. At the same time he put a 2.5" off road y pipe on it with a flowmaster y collector, and it sounds awesome. That catback sounds good on LT1s. I have only heard one sound clip of an LS1 car that sounded good with the A.T. flowmaster catback. It had longtubes, and a big cam in it.
http://media.putfile.com/flowmasterc...withmonstercam

1 Bad Ass Formula

iTrader: (7)

I have a Flowmaster muffler w/ stock exhaust on my car. It sounds fine to me, though people here say Flowmasters are restrictive. I'm thinking of getting a Borla or Magnaflow catback but am still a bit undecided. I'm looking from both sound and performance wise. All I know is that I really don't want to have raspy exhaust. My moms 96 Z28 had a Flowmaster muffler, and yeah it was much louder than the one on my car.

LS1W66

I still have My American Thunder Catback but it's a Single On the Left with a 2 chamber 40 series (not the restrictive dual outlet 80 series).

phoenix1987

iTrader: (3)

I have a 40 series 3inch in/3 inch out single on my LS1 3rd gen. Long tubes, no cats single sinch, sounds great under load. Getting rid of it for a dual/dual muffler!

ScrapinBye

Sounds EXACTLY like my '02 SS. I have the MS3 cam, Pacesetter LTs & ORY, and Flowmaster 80 CB. Sounds mean as ****. I'm about to install a cutout so I can have the best exhaust flow when I want, and sound awesome, or just enjoy the catback with the cutout closed!