Generation III External Engine LS1 | LS6 | Bolt-Ons | Intakes | Exhaust | Ignition | Accessories
Sponsored by:
Sponsored by:

How bad is flowmaster?

Thread Tools
 
Search this Thread
 
Old Oct 2, 2011 | 03:14 AM
  #21  
99Bluz28's Avatar
TECH Senior Member
iTrader: (35)
 
Joined: Nov 2007
Posts: 9,705
Likes: 12
From: C. V., Kalifornia
Default

Originally Posted by 01ssreda4
I don't doubt independent research, however, Flowmaster makes a LOT of mufflers. Without specifying exactly which muffler you are talking about and what application the test was performed on, you have done no justice.
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.
Reply
Old Oct 3, 2011 | 12:58 PM
  #22  
darkvader0's Avatar
Staging Lane
 
Joined: Sep 2010
Posts: 94
Likes: 0
From: Austin, TX
Default

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.
Reply
Old Oct 3, 2011 | 02:26 PM
  #23  
Sladester2's Avatar
11 Second Club
10 Year Member
iTrader: (1)
 
Joined: Mar 2011
Posts: 1,194
Likes: 0
From: Southeast Missouri
Default

Hey darkvader, do you mind posting a sound clip of your cutout? I am thinking about getting one.
Reply
Old Oct 4, 2011 | 12:44 PM
  #24  
SSCamaro99_3's Avatar
TECH Addict
iTrader: (1)
 
Joined: Jan 2003
Posts: 2,551
Likes: 1
From: Ballwin, MO
Default

Originally Posted by arock24
I love my 40 series flowmaster, but then again I did not have the privilege of being able to go with LT's. I live in a zip code with very strict emissions and I don't know anybody to just slap on a sticker on my windshield. I had to go with ST Pacesetters, and I love the combo with my Flowmaster, and I get compliments all the time. If you're sticking with manifolds for now, no reason to spend extra money.
Given your location, all you have to pass is a computer test. A tune and you are golden.
Reply
Old Oct 4, 2011 | 05:41 PM
  #25  
arock24's Avatar
Launching!
iTrader: (4)
 
Joined: Sep 2011
Posts: 251
Likes: 0
From: PHX
Default

Originally Posted by SSCamaro99_3
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?
Reply
Old Oct 4, 2011 | 05:57 PM
  #26  
dontbl1nk's Avatar
On The Tree
iTrader: (1)
 
Joined: Nov 2010
Posts: 124
Likes: 1
From: Tulsa, OK
Default

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.
Reply
Old Oct 4, 2011 | 07:41 PM
  #27  
s346k's Avatar
TECH Junkie
iTrader: (4)
 
Joined: May 2005
Posts: 3,433
Likes: 1
From: johnson co.
Default

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.
Reply
Old Oct 4, 2011 | 10:03 PM
  #28  
kinglt-1's Avatar
TECH Senior Member
20 Year Member
Liked
Loved
Community Favorite
iTrader: (26)
 
Joined: Jul 2005
Posts: 5,894
Likes: 254
From: Ft. Wayne, IN
Default

Originally Posted by s346k
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.
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

 Verdad Gallardo
story-1

6 Common C5 Corvette Failures and What's Involved In Repairing Them

 Pouria Savadkouei
story-2

Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

 Verdad Gallardo
story-3

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-4

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-5

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo
story-6

Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

 Verdad Gallardo
story-7

Awesome K5 Blazer Restomod Comes With C7 Corvette Power

 Verdad Gallardo
story-8

10 Camaros You Should Never Buy

 
story-9

10 LS Engine Myths That Refuse to Die

 Verdad Gallardo
Old Oct 5, 2011 | 11:16 AM
  #29  
SSCamaro99_3's Avatar
TECH Addict
iTrader: (1)
 
Joined: Jan 2003
Posts: 2,551
Likes: 1
From: Ballwin, MO
Default

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.
Reply
Old Oct 5, 2011 | 02:32 PM
  #30  
SuperStock99's Avatar
Staging Lane
iTrader: (1)
 
Joined: Dec 2010
Posts: 55
Likes: 0
From: Charlotte, NC
Default

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.
Reply
Old Oct 5, 2011 | 02:41 PM
  #31  
lemons12's Avatar
TECH Senior Member
iTrader: (71)
 
Joined: Jul 2007
Posts: 11,088
Likes: 2
From: Winchester, TN
Default

Originally Posted by flowman
First - I will let you know I am the VP of marketing for Flowmaster - just to be honest going into this discussion. I'm not going to lay a bunch of PR on you. But a flowbench test on mufflers has NO relationship to performance. Only a dyno can determine power. Two points to consider - a flowbench measures constant flow air at room temperature. Exhaust, last time I checked, is hot air and flows as a pulse by virtue of the four cycle engine combustion. A chambered muffler works to draw the exhaust through the system - scavenging the exhaust, not inhibiting it. In recent tests (one month ago) at Westech Performance - with unbiased testing - our mufflers performed better than open exhaust and other "open - see right through it" mufflers. I welcome your independent testing.
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".
Reply
Old Oct 5, 2011 | 06:18 PM
  #32  
s346k's Avatar
TECH Junkie
iTrader: (4)
 
Joined: May 2005
Posts: 3,433
Likes: 1
From: johnson co.
Default

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.
Reply
Old Oct 5, 2011 | 06:39 PM
  #33  
JD_AMG's Avatar
TECH Senior Member
 
Joined: Jan 2004
Posts: 5,798
Likes: 16
From: St.Charles MO
Default

Originally Posted by arock24
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?
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.
Reply
Old Oct 5, 2011 | 10:42 PM
  #34  
firefighter34's Avatar
On The Tree
 
Joined: Oct 2005
Posts: 174
Likes: 0
From: Yakima, WA
Default Love the flowmaster

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..........

Reply




All times are GMT -5. The time now is 12:41 AM.

story-0
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-1
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-2
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-3
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-4
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-5
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-6
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE
story-7
Awesome K5 Blazer Restomod Comes With C7 Corvette Power

Slideshow: A heavily reworked 1972 K5 Blazer swaps its off-road roots for a low-slung street-focused build with modern V8 power.

By Verdad Gallardo | 2026-03-09 18:08:45


VIEW MORE
story-8
10 Camaros You Should Never Buy

Slideshow: There are thousands of used Camaros on the market but we think you should avoid these 10

By | 2026-02-17 17:09:30


VIEW MORE
story-9
10 LS Engine Myths That Refuse to Die

Slideshows: Which one of these myths do you believe?

By Verdad Gallardo | 2026-01-28 18:10:11


VIEW MORE