Flowmaster...or NOT

**Wesman** · 12-11-2007, 05:27 PM

Magnaflow.

I have Magnaflows on my dual exhaust setup, they are pretty tame at idle and under part throttle, but it sounds mean when you really get on it

**SilverSteen25** · 12-11-2007, 08:49 PM

Don't do the flowmaster...It sucks, atleast the 80 series does....I have it on my car right now.....It sounds alright, but it flows like shit.....I'm puttin a Borla adj on this spring.....My buddy has the SLP loudmouth on his SS, it sounds like shit too, too much damn crack and rasp, sounds like a tin can on wheels rollin down the road....Get a Borla, GMMG, Magnaflow or Hooker, but stay away from the 80 series flowmaster and the loudmouth

**0rion** · 12-11-2007, 10:09 PM

has anyone ever seen a catback shootout? For years I've read about how much flowmaster sucks. No one ever recommends them and everyone always says to stay away from them. What I haven't seen is proof that they suck. I'm wondering how much is internet folklore and how much is real. Lets say it is restrictive, how much HP is it costing people? I'm not saying that it's not out there but I would love to see a correctly done shootout. My guess would be that even if it doesn't make as much HP as the next catback the difference between it and any comparable catback would be pretty small. I'm not talking about putting it up against a loudmouth which doesn't even use a muffler. I'm talking about it against another catback that actually has a muffler. If anyone knows of a shootout please post a link to it because I'd love to see it.

**SilverSteen25** · 12-11-2007, 10:31 PM

Very true......I would love to see that too

**Frost** · 12-12-2007, 05:10 AM

Originally Posted by Frost

Check out this car: http://www.lsxtune.com/gallery-02.htm

before tuning, it made 373rwhp with a Flowmaster cat-back. Just after that pull, the exhaust was switched to a Hooker catback and the car (again, same day, same dyno) made 392rwhp. Only change was the catback. The car cracked a little over 400rwhp after some tuning.

This is my EXACT experience switching one out in real world conditions. For anyone who does not believe and would like to PM me, I can give you web-contact info of the owner of the car to ask him yourself if my statement is doubted.

**blue02Z** · 12-12-2007, 05:26 AM

when i had my flowmaster, i did not like the sound. magnaflow kills it with tone

**180ls1** · 12-12-2007, 06:49 PM

Originally Posted by 0rion

has anyone ever seen a catback shootout? For years I've read about how much flowmaster sucks. No one ever recommends them and everyone always says to stay away from them. What I haven't seen is proof that they suck. I'm wondering how much is internet folklore and how much is real. Lets say it is restrictive, how much HP is it costing people? I'm not saying that it's not out there but I would love to see a correctly done shootout. My guess would be that even if it doesn't make as much HP as the next catback the difference between it and any comparable catback would be pretty small. I'm not talking about putting it up against a loudmouth which doesn't even use a muffler. I'm talking about it against another catback that actually has a muffler. If anyone knows of a shootout please post a link to it because I'd love to see it.

http://www.allfordmustangs.com/forum...-shootout.html

its on a mustang but good to see

**PFM** · 12-13-2007, 07:41 AM

I like the Hooker Catback on my car. Its nice and quiet when it needs to be and has a nice tone to it when the longtubes start talking. When I got the car somebody had done the lets take off the stock muffler and replace it with a flowmaster mod. You've all seen them before. Looks like a step muffler. All kinda sizes of exaust pipe was pieceing that bitch on. But when I put on a set of long tubes the car sounded like a truck coming down the road. I run a DMH cutout so I can go from hooker quit to cutout loud.

**drummer52910** · 12-14-2007, 04:57 PM

I have the Flowmaster catback on my camaro. Sounds amazing at WOT. Ya i it may not make as much power as some other catbacks but the sound is damn good. Though i havent really driven anything different to compare.

**89LX** · 12-14-2007, 05:40 PM

Having read these forums for sometime I would think Flowmaster has done likewise. I doubt there is any significant difference between the majority of the Catback out there IMO. There are some that might flow higher but the muffler is probably more for looks than muffling, can't have both worlds. I have the Hooker and like the sound.

**shady milkman** · 12-14-2007, 05:41 PM

suckmaster dont flow..get yourself a magnaflow or better

**bgable** · 12-17-2007, 11:42 AM

Originally Posted by Frost

Check out this car: http://www.lsxtune.com/gallery-02.htm

before tuning, it made 373rwhp with a Flowmaster cat-back. Just after that pull, the exhaust was switched to a Hooker catback and the car (again, same day, same dyno) made 392rwhp. Only change was the catback. The car cracked a little over 400rwhp after some tuning.

car had h/c and catback n barely broke 400rwhp?whats with that most cars with h/c easily break 400 rwhp?

**Bottesini** · 12-17-2007, 11:49 AM

With my TD setup I have a pair of Dynomax 18" bullets. I like the sound and flow well. Much quieter setup then what the car had when I bought it a single Flowmaster 10 with a Y and 3" pipes that dumped before the axle. Granted open headers was quieter inside the car then that setup.

**MNR-0** · 12-17-2007, 11:59 PM

I love how ppl. post how FMs they suck when thay have no FRIGGIN IDEA.

I love how they say 80 serires suck and its innuendo that assumes this is the standard FM. NOT! It's a stock replacement muffler, period.

The 2 and 1 chambers flow well and for street they rule with sound but for outright performance I wouldn't go ANY muffler. Short dumps off the headers is the only way for premium performance.

The FM race series stuff is also pretty cool - simple, but cool.

Tell me, with dual 3" 2-chambers that will flow 500fwhp, who has this kind of power that they need more? Certainly not the bolt-on crowd and even some of the cammed stuff.

Don't believe the crap you hear on the internet. Do your own research and choose what sounds best for you on the street, and performs best for you at the strip (if that's your thing). You can't have both - and anyone who says otherwise should get their hand out of their ass.

**shady milkman** · 12-18-2007, 05:31 AM

Originally Posted by MNR-0

I love how ppl. post how FMs they suck when thay have no FRIGGIN IDEA.

I love how they say 80 serires suck and its innuendo that assumes this is the standard FM. NOT! It's a stock replacement muffler, period.

The 2 and 1 chambers flow well and for street they rule with sound but for outright performance I wouldn't go ANY muffler. Short dumps off the headers is the only way for premium performance.

The FM race series stuff is also pretty cool - simple, but cool.

Tell me, with dual 3" 2-chambers that will flow 500fwhp, who has this kind of power that they need more? Certainly not the bolt-on crowd and even some of the cammed stuff.

Don't believe the crap you hear on the internet. Do your own research and choose what sounds best for you on the street, and performs best for you at the strip (if that's your thing). You can't have both - and anyone who says otherwise should get their hand out of their ass.

Muffler Flow Comparison Chart
Shown below are competitive mufflers versus DynoMax Ultra-Flo SS and Race Magnum Welded models. For Powertech Index cold-flow testing, the pressure drop across the muffler is held at 20.3" H2O and the flow rate (scfm) is recorded.

MODEL (Flow Rate- @ 20.3" H2O) Muffler Inlet Size

+ Edelbrock 5501 492 scfm 2.25"
$ Flowmaster 42440 483 scfm 2.25"
Race Magnum Welded 17216 711 scfm 2.25"

+ Edelbrock 5511 579 scfm 2.50"
$ Flowmaster 42540 352 scfm 2.50"
Ultra-Flo SS 17263 1133 scfm 2.50"
Race Magnum Welded 17218 1000 scfm 2.50"
# Borla 40600 836 scfm 2.50"

+ Edelbrock 5505 708 scfm 3.00"
$ Flowmaster 43040 392 scfm 3.00"
Ultra-Flo SS 17296 2200 scfm 3.00"
Race Magnum Welded 17220 2200 scfm 3.00"
# Borla 40450 1400 scfm 3.00"
# Borla 40575 1100 scfm 3.00"

@ Edelbrock 5535 562 scfm 3.50"
$ Flowmaster 435409 576scfm 3.50"
Ultra-Flo SS 17268 2200 scfm 3.50"
Race Magnum Welded 17224 2200 scfm 3.50"
# Borla 40615 854 scfm 3.50"

@ Edelbrock 5537 1400 scfm 4.00"
* Flowmaster 54040-10 634 scfm 4.00"
Race Magnum Welded 17225 2600 scfm 4.00"
# Borla 40741 1450 scfm 4.00"

were did you find this info on 500fwhp? secondly just because it can flow 500fwhp doesnt mean it does it nearly as efficiently as any other brand..the ls1 stock t/b can handle 500 at the crank..but i guarantee you that it wont flow as efficient and limit the power compared to a fast 90 or even a fast 78.....for the price to get a performance muffler from flowmaster...you might as well get one that flows exponentially better then the flowmaster offering. if you got this info from flowmaster ect. be careful as you should already know..certian companies like to boost their numbers *cough* slp and k&n *cough* i have done my research, quite a bit, so i am not talking out of my ass.

**craz1469** · 12-18-2007, 02:48 PM

Hooker +1000... I'm on my 3rd exhaust and I am very happy with Hooker. Nice a quiet until WOT. But then its still not insanely loud.

**N20LT4** · 12-19-2007, 09:55 AM

I've been a fan of the Flowmaster sound for years, and have had numerous of their American Thunder applications. I think that only the more costly systems can out-sound the Flowmasters hands down, but as for flowwise I wouldn't recommend them. I just recently replaced my 3" 2-chamber Cat-back (for a B&B Tri-Flo system), and oh boy what a difference. But just because I spent $730 on a cat-back system doesn't mean you have to to get better results. Both Magna Flo and Dynomax are great alternatives to Flowmaster. Personally, and for around the same price range, I would stay away from the Hooker and MAC systems as I just don't like the sound of either.

**TransAm11973** · 12-19-2007, 10:01 AM

heard loudmouths are raspy and sound like crap

**N20LT4** · 12-19-2007, 10:07 AM

That's why the "Dynomouth" and "Borlamouth" custom kits were created

**craz1469** · 12-19-2007, 03:01 PM

Originally Posted by TransAm11973

heard loudmouths are raspy and sound like crap

That was my first system, I loved the way it sounded when I had manifolds and cats. But after the headers and ory it went to sounding like death. Very loud and nothing but rasp. Your Y-pipe has a lot to do with your rasp also. The smoother the transition the less rasp. I swap the TSP 4 piece ory for a Pacesetter and I noticed a big differents. If you have the cash get a custom Y with one of these flowmaster pieces. It will smooth out the tone.
http://store.summitracing.com/partde...5&autoview=sku