How bad is flowmaster?
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Teching In
Joined: Feb 2007
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How bad is flowmaster? I have been doing a lot of research on which exhaust I am going to put on my car and obviously there are three considerations, Price Sound and Performance. True duals have the obvious performance advantage but are killers in the price arena so I have decided to go Y. These all seem to be roughly the same price, so based on sound I have always liked the old school Chambered sound of Flowmasters, the only thing that I have heard on our cars that comes close to this type of sound is the GMMG, which is quite expensive. So my question is what makes the Flowmaster so bad? All I could find were claims of restriction but no evidence, I understand that by virtue of the design it will not flow as well as SLP, but corsa is designed with the same type of muffler system and seems to get no corrisponding disdain. What am I missing here?
In my opinion, unless you have a TON of horsepower, you probably arent going to notice a difference. The change in hp between a flowmaster catback and an slp would probably be <5hp.
I have a flowmaster muffler with stock Y and I LOVE the sound. Not too loud, but gives it the aggressive tone. Not too expensive either.
Bottom line...go with sound over performance unless you are planning a big build.
I have a flowmaster muffler with stock Y and I LOVE the sound. Not too loud, but gives it the aggressive tone. Not too expensive either.
Bottom line...go with sound over performance unless you are planning a big build.
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From: St.Charles MO
I have been doing a lot of research on which exhaust I am going to put on my car and obviously there are three considerations, Price Sound and Performance. True duals have the obvious performance advantage but are killers in the price arena so I have decided to go Y. These all seem to be roughly the same price, so based on sound I have always liked the old school Chambered sound of Flowmasters, the only thing that I have heard on our cars that comes close to this type of sound is the GMMG, which is quite expensive. So my question is what makes the Flowmaster so bad? All I could find were claims of restriction but no evidence, I understand that by virtue of the design it will not flow as well as SLP, but corsa is designed with the same type of muffler system and seems to get no corrisponding disdain. What am I missing here?
But anyway, you did not search hard enough, this took me like 5 min:
https://ls1tech.com/forums/generatio...-mufflers.html
2 ½” Inlet/Outlet Dynomax Super Turbo 278 CFM
2 ½” Inlet/Outlet Ultraflow Bullet 512 CFM
2 ½” Inlet/Outlet Gibson Superflow 267 CFM
2 ½” Inlet/Outlet Flowmaster ( 2 Chamber) 249 CFM
2 ½” Inlet Outlet Flowmaster ( 3 Chamber) 229 CFM
2 ¼” Inlet/Outlet Thrush CVX 260 CFM
2 ½” Inlet/Outlet Maremount Cherry Bomb 298 CFM
2 ½” Inlet/Outlet Hooker Aero Chamber 324 CFM
2 ½” Inlet/Outlet Hooker Max Flow 521 CFM
2 ½” Inlet/Outlet Borla Turbo 373 CFM
2 1/2" Inlet/Outlet Magnaflow 284 CFM
2 ½” Inlet/Outlet Ultraflow Bullet 512 CFM
2 ½” Inlet/Outlet Gibson Superflow 267 CFM
2 ½” Inlet/Outlet Flowmaster ( 2 Chamber) 249 CFM
2 ½” Inlet Outlet Flowmaster ( 3 Chamber) 229 CFM
2 ¼” Inlet/Outlet Thrush CVX 260 CFM
2 ½” Inlet/Outlet Maremount Cherry Bomb 298 CFM
2 ½” Inlet/Outlet Hooker Aero Chamber 324 CFM
2 ½” Inlet/Outlet Hooker Max Flow 521 CFM
2 ½” Inlet/Outlet Borla Turbo 373 CFM
2 1/2" Inlet/Outlet Magnaflow 284 CFM
Replaced with a Hooker catback (which is cheap as well, like $350) and it sounds so much better(much more exotic, yet with more "burble" and a nice tone), and I noticed a seat of the pants difference in power and throttle response.
Kooks has a great True dual system. GM High Tech Performance mag did an install article and I'm sold on it! It's just too bad I wanna do a side exit exhaust, but now I might consider true-dual w/X-pipe side exit.
There was a brand new Flowmaster cat back on my car when I purchased it. I hate it. It's too quiet, doesn't sound that good and doesn't really look good either. Go with something else... Never been a Flowmaster fan on anything other than a Mustang.
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Thread Starter
Teching In
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Thanks for the advice guys, I dont plan on ever doing too much work to my car and im not chasing numbers or 1/4 mile times so I think im going to go with the flowmaster, Eventually I plan on doing LTs and I might change it up then. Ill let you guys know what I think after I put it on. Glad to hear some positive reviews
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I have a Flowmaster muffler welded into my stock cat back. I have a cutout in place of the cat and I'm making about 280 rwhp, at the track I gained .6 mph with the cutout open vs closed. Everybody says a Flowmaster hurts performance but at my power level I'm not seeing it. I get positive comments all the time on how good my car sounds.
from all ive read, dual exhaust is useless unless youre making huge power, big cubes, or running super/turbo chargers. ive also always heard that the flowmasters for LS1 fbodies LOSE power as apposed to gaining power. they restrict the exhaust flow.
i have pacesetter LTs, TSP catted Y, and an SLP original loudmouth. i get compliments everywhere i go, especially on track days, where there is everything from piece of **** ricers, to 5th gens, vettes, mustangs, porsches, and full race cars. out of all them, people walk up to my car and say how good it sounds.
i have pacesetter LTs, TSP catted Y, and an SLP original loudmouth. i get compliments everywhere i go, especially on track days, where there is everything from piece of **** ricers, to 5th gens, vettes, mustangs, porsches, and full race cars. out of all them, people walk up to my car and say how good it sounds.
several years ago when i had LTs and a Hotcam i picked up 32 rwhp removing my cats and upgrading from flowmaster muffler to TSP Rumbler catback.
flowmaster does sound good, but the performance isn't too good. for the same price you can buy something else that flows better and sounds just as good.
for making power, having your exhaust right is the first real step
flowmaster does sound good, but the performance isn't too good. for the same price you can buy something else that flows better and sounds just as good.
for making power, having your exhaust right is the first real step
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From: Central Indiana Honors: 4th grade spelling bee contestant
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From: Turnin' Wrenches Infractions: 005
Flowmaster catbacks don't flow great on these cars but most say they sound good. If you want similar sound but better flow, then move to a 2 chamber or single chamber. Problem solved.
In my opinion if your just doing a catback and you like the sound of flowmaster use it. It may not flow the best compared to catbacks that are 2-3x more expensive but you get a good sound. Besides I read in a car magazine that until you change around 20hp you cant fell a difference unless at the track of course.
Yes I have flowmaster on my car I love it I can stand to lose 5hp or whatever nbd. Btw single chamber 40 series flow the best
Yes I have flowmaster on my car I love it I can stand to lose 5hp or whatever nbd. Btw single chamber 40 series flow the best 
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.
Last edited by arock24; Oct 1, 2011 at 07:11 PM.
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flowbench vs dyno 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.
Joined: Aug 2007
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From: Turnin' Wrenches Infractions: 005
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.