Magnaflow vs Flowmaster

[nick8086]

Magnaflow vs Flowmaster

I have to replace the muffler on my Chev truck.. Which one is better???

The price is the same...

2006 Chev Truck..

It is the truck I use to tow my old cars...

[rocketraider]

Magnaflow or DynoMax. Flowmasters are great for noise, but have been repeatedly proven to not significantly increase HP or fuel mileage. I think you'll rapidly grow tired of their drone too esp towing a loaded trailer.

For that matter you could probably eliminate the muffler completely and just run thru the cat alone, without excessive noise. That worked well for 90s vintage trucks but may make an 06's ECM go nutty.

[joe_padavano]

Define "better". The Flowmaster is better at being obnoxiously loud, droning on the freeway, and pi$$ing off the neighbors. Despite that, it is consistently among the most restrictive muffler in published flow tests. I second Glenn's comment - consider Walker Dynomax Turbos.

Google Flowmaster drone. Also Google Flowmaster flow tests.

[Phillip Cole]

Sound and performance are both important. The right Magnaflow gives a throaty sound. IMO it is a classic sound. Since you drive the truck to tow cars, you would regret just loud in the long run. My muffler shop recommended Magnaflow for those reasons.

[rocketraider]

I have Flowmasters on my 74 Hurst- because at the time, they seemed like the best option (DynoMax came out a couple years later). I won't put them on anything again.

A Mopar friend once told me "turn that loudass Oldsmobile off!!" after I had put the Flows on it... Coming from a Mopar guy, I soon figured maybe it was too loud.

[joe_padavano]

I have Flowmasters on my 74 Hurst- because at the time, they seemed like the best option (DynoMax came out a couple years later). I won't put them on anything again.

Actually, the Walker Turbo mufflers have been available since the Corvair Turbo was sold. I installed a pair on my 1968 442 back in 1975. The DynoMax performance brand name came later, but the basic muffler has been around for decades. The 14" case, 2.5" inlet/outlet Turbo is a great sounding, good-flowing muffler that doesn't beat you up.

[Matt Harwood]

God I HATE Flowmasters. If you want to sound like a kid in a Camaro with his hat on sideways, that's definitely the muffler you need. Every car I've driven with Flowmasters gets an annoying drone at highway speeds that feels like your forehead is caving in. But if that's what you want, go for it. Otherwise, ANYTHING ELSE is better.

A muffler won't add horsepower, it'll just make it sound faster. I have Dynomax mufflers on my 1993 Mustang and like them because they're not too loud. I don't like to advertise my presence to the local constabulary with excessive exhaust noise...

[Guest]

While performance mufflers and modified cars really don't belong in the General section of the forum I myself do have modified cars. One of my cars that I built for Grand Touring (road racing) and street use when first built was using DynoMax. For about a year ( to qualify everything up stream from the mufflers there was no engine malfunctions like backfiring etc.)everything was fine until I started noticing a noise coming from one of them. One of the mufflers came apart inside, the guts rattling around. Outside shell, like it's twin was shiny like new. These mufflers had les than 2,000 miles on them. I still have them in the garage as a show and tell piece. I replaced them both with Flow Masters and have never had any problems with them. As far as noise goes, you just have to pick the right type of FlowMaster. The little short ones do make a lot of noise, but you can buy the long ones that won't drive you out of the car. I have much more track time on the FlowMasters than the DynoMax and they have been no problem. High Performance Pontiac magazine did some extensive testing (not noise) on HP and backpressure of many brands ( some which some of you have never heard of ) and found FlowMasters one of the best as far as HP retention and backpressure flow rates.

[JACK M]

I was reading recently that where you place the muffler will make a difference on the sound. Farther back vs. near the header.

I would interview a good custom exhaust guy and see what he says.

As suggested, on a rig that you tow with you may get tired of the loud.

[Guest]

I was reading recently that where you place the muffler will make a difference on the sound. Farther back vs. near the header.

I would interview a good custom exhaust guy and see what he says.

As suggested, on a rig that you tow with you may get tired of the loud.

Jack, what was the difference in noise level. my guess is the further back the less noise and pressure. I know on exhaust pipes vs. tail pipe that HP wise it makes little difference when the tail pipe ( after the muffler) is necked down from a 2 1/2" exhaust pipe to a 2" tail pipe. Many manufacturers do this as a matter of course.

[nick8086]

Define "better". The Flowmaster is better at being obnoxiously loud, droning on the freeway, and pi$$ing off the neighbors. Despite that, it is consistently among the most restrictive muffler in published flow tests. I second Glenn's comment - consider Walker Dynomax Turbos.

Google Flowmaster drone. Also Google Flowmaster flow tests.

Being obnoxiously loud,. That is what my son wants...

I going to check the warranty and make the choice... I can only pick from the two...

Thanks for the help... Will take it in next week...

The loud sound does not matter to me.. The truck was already loud and I got use to it...

Edited January 8, 2015 by nick8086 (see edit history)

[Matt Harwood]

Sometimes it's a parent's job to prevent their children from being idiots. This is one of those times. If you have to spend any amount of time in the truck, regardless of what your son wants, please, do not put Flowmasters on it. Unless he's the exclusive driver of said truck, you will regret it within moments of getting on the highway.

PS: Mufflers have no effect on warranty coverage. Put whatever muffler you want on it and the dealer can't void anything.

[Guest]

Sometimes it's a parent's job to prevent their children from being idiots. This is one of those times. If you have to spend any amount of time in the truck, regardless of what your son wants, please, do not put Flowmasters on it. Unless he's the exclusive driver of said truck, you will regret it within moments of getting on the highway.

PS: Mufflers have no effect on warranty coverage. Put whatever muffler you want on it and the dealer can't void anything.

Depends on which Flowmasters you use.

[nick8086]

I was going to check the warranty muffler... 3 years or lifetime...

[Restorer32]

I knew my Son was growing up when he decided to replace the FlowMasters on his Camaro with something a bit quieter. I did manage to resist the "I told you so".

[joe_padavano]

Being obnoxiously loud,. That is what my son wants...

It's not the loud that's the problem. It's the incessant droning at highway speeds that will drive you crazy in a short period of time.

[30DodgePanel]

He's going to do it Matt. You tried but one can clearly see he has his mind made up.

He'll regret it.

I modified an exhaust system on a truck I used for towing ( 2003 Dodge Hemi ) with a flowmaster. The fun cool sound for my son lasted maybe a week, a year later I went back to factory exhaust. Expensive lesson learned!

[supersix]

I had Flowmasters on a '69 GTO and currently have them on a '67 Camaro. As helfen stated above, it's all a matter of which series Flowmaster you have. Also, as stated above, it matters where the muffler is placed. I used the quieter series on the Camaro and GTO and is was not obnoxiously loud and no drone.

[Guest]

I had Flowmasters on a '69 GTO and currently have them on a '67 Camaro. As helfen stated above, it's all a matter of which series Flowmaster you have. Also, as stated above, it matters where the muffler is placed. I used the quieter series on the Camaro and GTO and is was not obnoxiously loud and no drone.

Thank You!

[Guest]

Just remember that the type of muffler and muffler placement is most important in regard to the noise problems. Lets be honest, where drone noise is concerned most of the the noise comes from systems where dumps were used. The sound is directed at the pavement and bounces back at the floor of the vehicle. I see many muscle cars today with dumps, and many with short stubby FlowMasters or Walkers or DynoMax and they all make the droning noise when they are plumbed that way. What is attached to the muffler??? NO tail pipe or in some cases no tailpipe and resonator. That is what these people want, however that seem to be giving some manufacturers a bad reputation. Check these images.

This type of plumbing is not what we want, nor is it legal in many states or ignored in many states. But this is what many people do;

https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcTw5SKgeuXH7xNPwdkNVGBzY0Zo-SXpaMgOBhy2sKpKKuTej8AB

This is what a performance exhaust should look like with tail pipes up and over the axles and out the back....not dumped from the muffler from the exhaust pipe ahead of the rear axle.

Edited January 8, 2015 by helfen (see edit history)

[JACK M]

Jack, what was the difference in noise level. my guess is the further back the less noise and pressure. I know on exhaust pipes vs. tail pipe that HP wise it makes little difference when the tail pipe ( after the muffler) is necked down from a 2 1/2" exhaust pipe to a 2" tail pipe. Many manufacturers do this as a matter of course.

I cant remember where I read this but it was implied that the tone (not the loud) would be different with the muffler placement. Mellower tone if in the rear vs raspier towards the front with no resonators.

I may be remembering this backwards so would consult an expert as I suggested earlier.

[John348]

I went through the same thing with my son. He has a 85 K/5 Blazer that we fixed up for him to play with. He wanted headers and pair of cherry bombs. His main purpose was to plow snow. After one season of pushing snow in low gear and reving at around 4,500 RPM, the exhaust went to stock, and the headers came off. Burning up plug wires is bad enough, but having to replace one at 2AM in a blizzard is entire different problem. I learned how to say "I told you so" just by eye contact. Looking back at my life there are many things I had to learn the hard way also.

[R W Burgess]

.....Burning up plug wires is bad enough, but having to replace one at 2AM in a blizzard is entire different problem. I learned how to say "I told you so" just by eye contact. Looking back at my life there are many things I had to learn the hard way also.

Now see John, you and the others are just spoiling your youngens! That young fellow of yours learned how to replace spark plugs under bad conditions, and probably also learned where to buy ear muffs in a pinch. Some things you just can't explain to young people. Explains why I will never own a motorcycle again.

[Guest]

My view is never put headers on a street car, it's like putting two big 2000+ degree radiators under the hood... I shake my head when I see them on street cars at car cruises...

Flowmasters don't need to flow as well as conventional mufflers, they trick the motor into thinking the beginning of the muffler is the outlet... That's what an engineer told me anyway.. I think they sound like hell, almost as bad as a six cyl with a glass pack... Hard to beat that big factory Chevy muffler with dual inlets.. The muffler on my 2001 Chevy 3500 still looks like new....

Having Tinnitus is fun too, I think I'm back in school and the dismissal bell is going off, lol....

So now we've moved on to headers in our talk about mufflers. I just don't know what some of you will do when you realize that most manufacturers have been using FACTORY tubular equal length stainless steel HEADERS well over fifteen years now. As far as tricking the engine, that might be true of newer cars that are controlled by a engine management system that adjust the fuel requirement in relation to what it's O2 sensors are telling it. As far as the old cars go, Mopar, Ford, and GM's Chevrolet and Pontiac have been using Factory headers since at least since 1960. Pontiac's first factory header ( with a Pontiac part # ) goes back to 1958. In Pontiac's case the factory made three types. Tubular header- NASCAR, cast iron equal length header- NASCAR, and for drag racing only a aluminum header made for short runs at full throttle. All with factory part #'s and all available over the parts counter or when ordering the car new. My 69 Pontiac has factory headers...and I ordered it that way new from the factory.

As I said before, the type of performance muffler, where the muffler is located, and the use of a tailpipes after the exhaust pipe and muffler instead of dumps at the muffler exhaust exit. will not cause the sound to be overbearing.

As far as my daily drivers, a 2012 and a 2001, both have stainless steel Factory tubular headers. Both are not considered performance cars.

Edited January 9, 2015 by helfen (see edit history)

[joe_padavano]

My view is never put headers on a street car, it's like putting two big 2000+ degree radiators under the hood... I shake my head when I see them on street cars at car cruises...

Cast iron conducts heat also. After a few minutes of running, manifolds will be at the same temp as headers. Ceramic coat either and you'll add some insulation, but no insulation is perfect and eventually the outside temp will reach steady state. As for the "need" for an efficient exhaust flow, anything you do to improve flow in or out of the motor will help with economy as well as power. Many new cars have stainless steel tubular "manifolds" that are essentially shorty headers. You don't get the tuned scavenging, but you do get the flow improvement and weight reduction. The fact that you shake your head doesn't negate the fact that they are proven to have a benefit even on the street.

Flowmasters don't need to flow as well as conventional mufflers, they trick the motor into thinking the beginning of the muffler is the outlet...

Actually, they trick the buyer into thinking they are an improvement...

[R W Burgess]

Magnaflow vs Flowmaster

I have to replace the muffler on my Chev truck.. Which one is better???

The price is the same...

2006 Chev Truck..

It is the truck I use to tow my old cars...

Nick, my experience is that most people wouldn't be able to tell the difference. If you want the sound further away from you, send the pipes straight out the back. Your 2006 Chevy is so well insulated, you probably won't know the difference anyway. I split the exhaust on my 2003 pu years ago with a dual outlet Flowmaster, never had a problem with it.

Recently, I took the resonator from the end of my exhaust on my 2007 Suburban.(It's for sale(85,000miles)-here's why....)

I plan to do something similar to my 2015 model waiting to be built.

[Bob Hill]

I have had both and my experience is that Magnaflows are much better - nice throaty sound and still relatively quiet in the cabin. I had FLowmasters on one of my late model Corvettes and I couldn't hear myself think inside. My wife refused to ride with me with them on.

Bob

[supersix]

I have had both and my experience is that Magnaflows are much better - nice throaty sound and still relatively quiet in the cabin. I had FLowmasters on one of my late model Corvettes and I couldn't hear myself think inside. My wife refused to ride with me with them on.

Bob

What series Flowmaster did you have in the Corvette?

[Bob Hill]

I don't remember as it has been a couple of years ago

Bob

[John348]

Guys

I am sorry I did not to bring up headers or intend to drift the conversation from aftermarket mufflers. Loud mufflers, seem to go hand and hand with headers, and the practicality of their use to go with youth decision. For myself the inconvenience out wieghs any gains

[Guest]

Guys

I am sorry I did not to bring up headers or intend to drift the conversation from aftermarket mufflers. Loud mufflers, seem to go hand and hand with headers, and the practicality of their use to go with youth decision. For myself the inconvenience out wieghs any gains

Then how do you explain stainless steel individual tube headers on virtually all new cars. Most people don't even know they have them.

[Matt Harwood]

Modern exhaust manifolds aren't like aftermarket long-tubes like most guys are talking about (which are leak-prone), but rather highly specialized manifolds that are made of tubing instead of cast iron. Actually, most modern cars using such designs use a double-wall construction to keep heat inside for quick catalyst light-off--any heat not radiating to the engine bay is purely a side-effect. Obviously a header can be more efficient than a log-style cast iron manifold, whose primary virtues were low cost, low maintenance, and easy packaging. These modern manifolds control noise almost as well as cast iron due to their construction, and by using heavy flanges, they do stay tight and leak free, which is also aided by the design, which usually uses a metal gasket of some kind with an O-ring seal. That's in direct contrast to the headers about which most guys are talking which had individual flanges on the tubes which were often leak-prone and needed frequent re-torquing to stay put. Then there's the ball-socket design of the exhaust end of the things, which provides vastly superior sealing to the familiar triangular flange with a gasket and three bolts used on many early header designs. Were long-tubes a contributing factor to exhaust noise in the good old bad old days (and even today with some designs)? Of course. Were they the primary cause of the dreaded Flowmaster drone? Unlikely.

When I was doing R&D work for GM and we had one of the prototype C5 Corvettes, one of the things they asked us to do was try a variety of different exhaust manifolds, including a cast style setup that had individual runners much like a header. It actually made slightly more power on the dyno, but it was bigger and bulkier and when it came down to it, the differences were so miniscule as to be non-existent in the real world. The downside, which we only learned after the real science guys had a crack at it, was that the cast iron was absorbing too much heat instead of passing it downstream to the cat during cold starts, which is when your car is dirtiest. I'm guessing THAT was the final decision-maker for them to use the tubular style manifolds.

And with or without tailpipes, I have yet to drive a car with a Flowmaster muffler that both made more horsepower and didn't have an annoying drone at 1800-2200 RPM, regardless of size, type, or location. Dual mufflers on a Mustang or a single transverse muffler on a Camaro or one big one under a pickup truck bed, when you drop into overdrive at 65 MPH your head felt like it was going to collapse. It isn't because the noise coming out of the muffler is getting into the car (and therefore, putting it farther away or burying it under sound deadening materials has no effect), it's a resonance frequency that sets up a harmonic in the exhaust system itself, the floors of the car, or other pieces that all start to vibrate to create the sound. Almost all high-performance mufflers do this because stock mufflers are specifically designed and tested so as to not create these specific harmonic frequencies, which vary from car to car. It has been my experience in driving high-performance cars and trucks (several hundred, I'd say) that no muffler drones more than a Flowmaster, and some are quite tolerable without squelching flow. Unfortunately, my experience also suggests using mufflers to make horsepower is akin to using a thinner radiator so the fan doesn't have to work as hard to pull air through it--the theory is sound, but the real-world results are harder to quantify. Sure, you might end up with one of the rare combinations that doesn't drone, but if you Google "droning exhaust," you'll find that a non-droning Flowmaster is as common as a unicorn.

[mrspeedyt]

at my Kingman house every morning a fire department Dodge pick up truck with a utility body drives by... sounds so good and I'm sure it's bone stock V-8...

[MyJetstar1]

I have Flowmasters on my Olds, that the previous owner had installed. That big motor sounds great at idle through them, but that is about all. The drone at 40 to 50 mph is so bad, that I have to literally stick my head out the window to maintain eye focus. I am definitely not going through another summer with those things. I'm glad I ran across this string to give some alternative ideas.

[NTX5467]

Down here in DFW land, it seems that EVERY 5.0L Mustang isn't complete without a set of Flowmasters. I can tell them a mile away. Granted, these are probably the three-chamber models rather than the 4-chamber models.

In doing mufflers, you have to consider underbody spaces, too, which can dictate a rearward location rather than a "header muffler" at the collector.

One reason for the recent stainless steel OEM exhaust manifolds probably has to do with manufacturing complexity PLUS cold start emissions. The cast iron manifold (and cylinder head) act as "heat sinks" which means the catalytic converter (if equipped) sees less heat initially, which means it takes longer for the converter to get to operating temperature for decreased emissions. This is at the OEM level.

My experiences are that exhaust headers do not add that much underhood heat AND they dissipate heat better than cast iron manifolds (even the "factory header" models). Either one can cook spark plug wires that aren't loomed properly for the application. And then there's the ThermoTech wraps to keep all of the heat inside of the header.

One thing about it, the less "sound" which comes into the passenger compartment from the outside, the less the sound system amps will have to work to overcome it!

Just like "music", what one finds pleasurable can be "trying" on another.

A good while back, in the pre-Flowmaster days, somebody put a pressure/vacuum gauge on an exhaust downpipe, near the engine. At cruise, there was LITTLE pressure in the system. Whether with a single system or a dual system. It was at WOT and higher rpm that the backpressure really happened, on either stock system.

I believe that the ONLY muffler that flows better (when tested) than a straight piece of exhaust pipe is Borla, who also makes complimentary stainless steel exhaust systems. At one time (middle 1990s?), GM had their cat-back systems available through GM Accessories. The combination of their mufflers and the stainless pipe materials gave them a unique sound, which was specifically "no drone". The parts reps had some pickups with those systems installed so they could effectively demonstrate them to dealers.

There were, initially, the Corvair Turbo mufflers. Then the Chrysler Street Hemi mufflers (also OEM on '69 Polara 440 police cars, the highest top speed until the TPI Camaro v-8 police cars came online), followed by the Chrysler Imperial ('72 era) mufflers (Street Hemi, but longer for the longer wheelbase Chryslers with the same low-restriction levels), at the OEM level. The term "turbo muffler" became more generic, harkening back to the Corvair legacy, but could be "anything". Personally, I lean more toward Walker DynoMaxs, when possible and I've had excellent fit and durability from ALL Walker products as they are OEM-oriented in design and production. Just my experiences.

Great graphic, Joe!!

Enjoy!

NTX5467

Edited January 10, 2015 by NTX5467 (see edit history)

[R W Burgess]

I am the happiest married man alive! :confused:

*

*

Thank you Flowmaster! (Can't hear a thing my wife says!:cool:)

[capngrog]

In the spring of 1994, I installed Ford stainless steel headers and a Flowmaster exhaust system on my 1993 Mustang 5.0. They sounded great then and still sound great today. I have never noticed a "droning" noise at highway speeds, and there is nothing wrong with my hearing ... even today at 70 yrs. old. Eh, what'd you say?

Nothing beats Pratt & Whitney for "droning" noise at cruising speed.

Still likin' my headers and Flowmasters,

Grog

[AndyC]

How about old school. Had the exhaust done on my 62 chrysler a few years ago, and the guy at the shop suggested dual GLASS PACKS. Nice throaty rumble at idle, and not too loud at speed.

Edited January 10, 2015 by AndyC (see edit history)

[MyJetstar1]

How about old school. Had the exhaust done on my 62 chrysler a few years ago, and the guy at the shop suggested dual GLASS PACKS. Nice throaty rumble at idle, and not too loud at speed.

I've considered the ol' glass packs. I had more than one car when I was a kid, with a "cherry bomb" sticker on the quarter glass. I don't know if I'm showing my age, or just my stupidity as a kid, but we used to pour gas in them and burn the glass out before they ever went on the car. It was against the law to run strait pipes, so if the officer that pulled me over that day looked under it, it had mufflers!

[nick8086]

Here is the break down..

Stock Muffler from the dealer 895.00. for the part only..

Magnaflow or Flowmaster - and the pipes to the back of the truck -- 349.00 installed with tax..