Flowmaster FlowFX Installs

[Chris Evans]

I haven't seen anyone install the Flowmaster FlowFX on anything older than mid 90 to newer GMs. Has anyone put these on their squarebody? I like the sound and they aren't overly expensive. Just curious.

 

[78C10BigTen]

Personally never heard of them. I do have flowmaster super 44s on my truck though.

 

[Chris Evans]

I had 40s on a couple other vehicles, and they sounded good, just had a drone on the highway and interstate. I'm sure some good insulation would have made it better.

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Flowmaster's promotional video on them

 

[RecklessWOT]

Personally never heard of them. I do have flowmaster super 44s on my truck though.

Flowmaster makes so many different types of mufflers it's surprising, I haven't heard of most of them either. I just googled it though, it's a straight through welded case muffler that's offset and filled with fiberglass packing kinda like a Dynomax muffler. Not a chambered muffler like the 40 series.



I guess the reason you don't see a lot of them on older stuff is most guys with older stuff like the sound of chambered mufflers better. It gives older engines a mean growl. A glasspack doesn't do a lot for changing the tone or add any cool pingy sound, it literally just quiets it down some. So yeah they flow better and sound louder than stock mufflers, but don't add anything to it. They're cool and all, but IMO they're kind of boring. I've used them on V6s before, made my 4.3 vortec in my s10 sound pretty cool, but I wouldn't want one on a V8. When I think of flowmaster I think of a raspy/throaty chambered muffler. At that point you might as well save some money and just throw some thrush glasspacks on it

 

[78C10BigTen]

The one other muffler sound i do really like are hooker aerochambers.

 

[Craig 85]

Never heard of them, but they have to keep up with Magnaflow. One reason I didn't go with this style of muffler or a true glasspack is due to the "rap" you get from them under full throttle and the same when you decelerate once they're blown. It's not as bad with newer vehicles running cats which will break up some of the sound waves.

I personally like the sound of chambered mufflers and I've had at least a dozen vehicles with them. This time I wanted a deeper sound, so I went with the Super 40's. They have a 5" thick case instead of the usual 4". My truck has a totally stock smogged down 454 with no cats. Tail pipes go to the rear bumper. It can be a little loud under acceleration, but I don't get any drone. I have not installed my interior yet, only boom mat at this point. At 65 MPH, I'm turning about 2500 RPM. I can say on my 2016 Ram Hemi 6.4L I had a 2 chamber Flowmaster and it droned horribly at 1800 RPM. Right at cruising speed. Once I changed it to a 3 chamber it stopped the drone.

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[Shorty81]

Never heard of them, but they have to keep up with Magnaflow. One reason I didn't go with this style of muffler or a true glasspack is due to the "rap" you get from them under full throttle and the same when you decelerate once they're blown. It's not as bad with newer vehicles running cats which will break up some of the sound waves.

I personally like the sound of chambered mufflers and I've had at least a dozen vehicles with them. This time I wanted a deeper sound, so I went with the Super 40's. They have a 5" thick case instead of the usual 4". My truck has a totally stock smogged down 454 with no cats. Tail pipes go to the rear bumper. It can be a little loud under acceleration, but I don't get any drone. I have not installed my interior yet, only boom mat at this point. At 65 MPH, I'm turning about 2500 RPM. I can say on my 2016 Ram Hemi 6.4L I had a 2 chamber Flowmaster and it droned horribly at 1800 RPM. Right at cruising speed. Once I changed it to a 3 chamber it stopped the drone.

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My truck sounds similar to yours. I have chambered Thrush mufflers over rear axle and out behind rear tires. I'm also 2500 rpm at 65.

 

[bucket]

The design of the oval case version is identical to the standard Magnaflow muffler and all the cheap carbon copies that are available. So if you have heard an old car or truck with Magnaflow mufflers, that's what the new Flowmaster will sound like.

Which by the way, the typical "glasspack" muffler (tube design, normally painted red) is a different and louder sound altogether. The louvered core produces a much different sound than a perforated core.

 

[Craig 85]

the typical "glasspack" muffler (tube design, normally painted red) is a different and louder sound altogether. The louvered core produces a much different sound than a perforated core.

Totally agree. I had some Cherry Bombs on my '68 El Camino. Even though I had it run out to the back bumper it was SO loud and had that rap. My old Muffler Guy was and ex-engineer from ET Mags. He used the old Blue Streak brand louvered glass packs. They sounded much better. His trick was to reverse the mufflers so the louvers faced the rear of the car. It cut down on turbulence and gave a more controlled sound to the muffler. They lasted longer too.

 

[Arkansas_V8]

Flowmaster usually show a drop in power while Magnaflow usually show an uptick. Engine Masters did a test on mufflers.

 

[kidego31]

I had a friend that run them for a couple months but took them off because they were to quiet for his taste. They sound good but are pretty quite. I got the thrush welded mufflers on mine and I love the sound. Not loud in the cab but sound great outside.

 

[bigcountry78]

Flowmaster usually show a drop in power while Magnaflow usually show an uptick. Engine Masters did a test on mufflers.

I’ve heard that flow masters had that effect, but I couldn’t find anything to really back that up. My flow masters are beginning to rust out and I’ll need som replacements. Do you have a link?

 

[Arkansas_V8]

I’ve heard that flow masters had that effect, but I couldn’t find anything to really back that up. My flow masters are beginning to rust out and I’ll need som replacements. Do you have a link?

I will pull it up on my TV and try and pin down the flowmaster point. Pretty sure it is after they stopped YouTube full posts. I may just video it and send it you.

 

[Arkansas_V8]

I’ve heard that flow masters had that effect, but I couldn’t find anything to really back that up. My flow masters are beginning to rust out and I’ll need som replacements. Do you have a link?

Good read from a trusted guy on another forum. Not linking it. Lol
From what I've seen on my dyno ANY similarly sized straight through design will out perform the Flow Master and this includes some glasspack "bullet" style mufflers that I bought at the exhaust shop for about $10 each. From our testing the Flow Masters while sounding good are generally no quieter than even these glasspacks on a 3 inch exhaust. Magnaflows, Dynomaxes and other straight through designs can quiet a 700 horsepower engine and not cost any power. The Flow Masters do sound good.....

A great test was last fall when I dyno tested a 511 Chevy. I had built the engine several years ago for a customer with a 1 ton 4x4 pickup. He had the truck all apart to do some fixing up and while the engine was out he wanted to dyno test it just for fun and to maybe find some power. We ran with some headers, mufflers and finally his entire exhaust system from his truck. When we swapped to it we lost about 20-25 horsepower across the board, torque was down about 30lbs/ft. He thought it was caused by the turn after the header needed to get around the transfer case. He had it set up so we could easily remove the mufflers which were right at the back of the system. We did this and the power was right back where it was with the previous combo of headers, and mufflers. Then we installed the Magnaflows on his system, no power loss. Then we switched to the $10 glasspacks, no power loss. This engine is built with oval port heads and 8.4:1 compression and a hydraulic cam. It made 430 horsepower and 530lbs/ft torque. As long as you were using the correct mufflers!

 

[Arkansas_V8]

I’ve heard that flow masters had that effect, but I couldn’t find anything to really back that up. My flow masters are beginning to rust out and I’ll need som replacements. Do you have a link?

I can't seem to find it in the videos. I will meander through all 4 seasons. I just don't have time right now.

I am not looking to bash all Flowmasters. I personally don't have a favorite exhaust brand. I like exhaust tubing and that is about it. Lol

Just that they don't perform as well as most mufflers.