Fiesta st Catback exhaust nobody is talking about.

[Jcherry41290]

Hey new to the forum !
happy fiesta owner 2019 magnetic grey, 65k, pet much bone stock. Getting ready to install a Catback I wonder why really nobody is talking about.
The flowmaster American thunder series. I’ve listened to every mbrp, Cobb, whoosh etc clip I could find on YouTube. I only had a few clips of the flowmaster system to make a comparison to, but to my ear, the richness and depth of the flowmaster system makes these other systems sound cheap. I had the mbrp in my eBay cart waiting for payment for awhile, because I know it’s a quality exhaust and a bit cheaper than the flowmaster system. But I just went with my gut and got the American thunder instead.
I have yet to install but I just wonder why there is no "buzz" around this system… nobody is talking about it really.

 

[dhminer]

I’ve always assumed there’s no hype around a product for good reason. Not sure why you’d get anything but Cobb if you want a 2.5” exhaust.

 

[ron@whoosh]

Hey new to the forum !
happy fiesta owner 2019 magnetic grey, 65k, pet much bone stock. Getting ready to install a Catback I wonder why really nobody is talking about.
The flowmaster American thunder series. I’ve listened to every mbrp, Cobb, whoosh etc clip I could find on YouTube. I only had a few clips of the flowmaster system to make a comparison to, but to my ear, the richness and depth of the flowmaster system makes these other systems sound cheap. I had the mbrp in my eBay cart waiting for payment for awhile, because I know it’s a quality exhaust and a bit cheaper than the flowmaster system. But I just went with my gut and got the American thunder instead.
I have yet to install but I just wonder why there is no "buzz" around this system… nobody is talking about it really.

We offered the Flowmaster system at one point. It drones a lot due to the muffler design which is commonly used on muscle cars, not small displacement turbo GDI engines
I love flowmaster for 5.0 Mustangs though
There are always a few used FM systems for sale on the FB groups, the tubing rusts very quickly & easily (hence the price / same for MBRP aluminized)

 

[M-Sport fan]

the tubing rusts very quickly & easily (hence the price / same for MBRP aluminized)

^^THIS is why I would not consider anything but a full 304 stainless system.

The op should also consider this factor, being right in the very heart of the midwestern salt soup in winter, rust belt.

 

[Dialcaliper]

I have the Flowmaster you’re talking about - the previous owner installed it on the car. It actually sounds very nice - a low grumbly idle and it barks like it means it on the throttle. It does sound less like a tuned 4-banger and more like half a factory V8 exhaust. Not sure if that’s good or bad.

Its a 2.5” system and not a 3”, so its also not as loud as some of the other more popular systems, which I actually kind of like. It does drone a bit at highway speeds, but the lower sound level makes it tolerable. To give you an idea of the interior sound level, The tiny little Kenwood sub the PO added under the drivers seat easily compensates for the bass the exhaust noise covers, and I easily can listen to music (factory sound system except the little sub) volume set down around 8-10. It doesn’t seem to bother the neighbors, even pulling in at night.

Its made of 409 stainless, so it won’t rust in milder climates, but it does turn a darker color, and if you have heavy winters and road salt, it might not be the best choice, especially if there’s salt around.

If I’d just been picking based on research, it might not have been my first choice. At first I was considering putting it back to stock, but it’s actually grown on me, and I don’t feel a need to change it out for something else even though I could probably afford to if I wanted.

For the price it’s a good value if you want some sound, but don’t want a loud 3” system and don’t live in a cold climate state

 

[akiraproject24]

I wanted the flowmaster based on the sound clips. I thought it sounded the best but in the end I went with the thermal r&d. 304 stainless and countless recommendations on the forums. Seemed like something was done right with it. I like it quite a bit too.

 

[Clint Beastwood]

We offered the Flowmaster system at one point. It drones a lot due to the muffler design which is commonly used on muscle cars, not small displacement turbo GDI engines
I love flowmaster for 5.0 Mustangs though
There are always a few used FM systems for sale on the FB groups, the tubing rusts very quickly & easily (hence the price / same for MBRP aluminized)

That's good to know, I've always been curious. I didn't have first-hand access to one so I ran a bunch of flowmaster fiesta ST videos through a spectrum analyzer and it didn't have the 106.67hz drone most 3" systems have but I guess maybe they were just recorded with poor quality mics.

 

[Geebs]

I've had the flowmaster on my car for the past 3 years and I really love it! I seriously have gotten many compliments about the sound.....it crackles and pops and has a pretty deep rumble plus it wakes right up under throttle. I don't drive in the winter so no idea about longevity though so that is something to consider.

 

[Dialcaliper]

That's good to know, I've always been curious. I didn't have first-hand access to one so I ran a bunch of flowmaster fiesta ST videos through a spectrum analyzer and it didn't have the 106.67hz drone most 3" systems have but I guess maybe they were just recorded with poor quality mics.

It helps that it’s a 2.5” system and not a 3” system…

Maybe sometime I’ll find a spectrum analyzer app and check it out, which should eliminate any audio/video compression issues.

I just looked some things up, and the iPhone at least has (or used to have) a low pass filter that cuts off everything below 200Hz. It appears some of the audio analyzers are able to bypass it temporarily, but any phone video recording might not include those frequencies or they may be greatly reduced, unless they were using a proper external microphone

 

[Clint Beastwood]

It helps that it’s a 2.5” system and not a 3” system…

Maybe sometime I’ll find a spectrum analyzer app and check it out, which should eliminate any audio/video compression issues.

I just looked some things up, and the iPhone at least has (or used to have) a low pass filter that cuts off everything below 200Hz. It appears some of the audio analyzers are able to bypass it temporarily, but any phone video recording might not include those frequencies or they may be greatly reduced, unless they were using a proper external microphone

Its not all phones though - but reviewing some videos, the better the quality of the exhaust the better the camera/audio quality is so it kinda makes sense a less expensive system doesnt typically have higher quality recordings. I used a pretty extreme audio setup when recording demo sounds for several systems, I forget how shitty phone mics can be haha.

 

[wcnST]

THIS!!!
https://www.amazon.com/gp/product/B08KCF4LD4/ref=ppx_yo_dt_b_asin_title_o08_s00?ie=UTF8&psc=1

 

[Clint Beastwood]

THIS!!!
https://www.amazon.com/gp/product/B08KCF4LD4/ref=ppx_yo_dt_b_asin_title_o08_s00?ie=UTF8&psc=1

eew - with the small res, no primary muffler, and the distance from resonator to tips, thats gonna make such a sharp "blatty" sound.

 

[Jcherry41290]

You guys have been helpful with all the feedback I really appreciate it ! I live in the rust and overly salted roadway capital of the United States so lol. It’s a good thing I garage the car in the winter. Hopefully that will stall the deterioration of the exhaust system… but it’s In my garage lol. Installing it Tuesday, I’ll give some feedback on sound quality and drone etc 👍

 

[Clint Beastwood]

You guys have been helpful with all the feedback I really appreciate it ! I live in the rust and overly salted roadway capital of the United States so lol. It’s a good thing I garage the car in the winter. Hopefully that will stall the deterioration of the exhaust system… but it’s In my garage lol. Installing it Tuesday, I’ll give some feedback on sound quality and drone etc 👍

You can get silver exhaust paint to help protect it and delay rust.

The point to look out for with drone is ~2700-3200rpm under partial load - that's where you get the nastiest ~107hz droning.
If you could reply back here with how it sounds (or even some sound clips!) of part throttle under load from 2700-3200rpm (ideally, up a grade or something) that would be really handy.

 

[Dialcaliper]

So I was fooling around with a spectrum analyzer app for my phone called “Sonic Tools” and got some interesting measurements of the primary frequency on the Flowmaster “American Thunder”. These are taken inside the car, sitting in the driver’s seat

Idle: 32 Hz @ 82dB

Frequency increases pretty linearly with RPM.
At some RPM some ~200Hz tones creep in especially with a little gas pedal, and sound level rises to about 85dB but that also includes road noise, which was pretty loud on that particular stretch of road on BFG rivals which are kind of noisy anyway.

Right around 3300 RPM, as it passes through 107-109 Hz, there is a very brief spike that depending on throttle position and gear reaches 90-98dB, and then subsides, which I would guess is your drone frequency.

The good news is that the “loud” RPM range is very narrow, as it starts to rise above 90dB above 3200 and subsides below 90dB before 3400 RPM, so you have to hold the car almost exactly at 3300 to get the drone, which is above most cruising speeds not the very broad 2700-3200 as mentioned above. 3300 in 6th is 84mph, so unless you cruise well above 80, it’s tolerable and you can still carry on a conversation without raising your voice.

We’re talking aftermarket exhausts which are obviously louder than stock, but the closest factory comparison I could find is a Porsche GT3 on the loud end at cruise is ~80dB, and new cars since 2016 (in the EU) are supposedly limited to 76dB interior noise at cruise.

I’ve not tested exterior noise, or interior noise at “full send”, but I found an obscure federal code that says new cars when revved in neutral at the engine speed equivalent to peak horsepower should not exceed 90dB interior noise. 🤣

Link to app - I’d be curious how other exhausts compare
https://www.google.com/search?q=ios...j0j4&hl=en-US&sourceid=chrome-mobile&ie=UTF-8

Edit: For some reason I had written Magnaflow instead of Flowmaster…long day.

 

[TyphoonFiST]

Thermal R &D Normal Version or Whoosh Thermal with Black tips for the Win*

 

[Dialcaliper]

Thermal R &D Normal Version or Whoosh Thermal with Black tips for the Win*

I’d be really interested to see if someone can take some measurements on the Thermal

 

[M-Sport fan]

^^^ They supposedly, somehow (without using a 20" foot long resonator, as some have suggested is necessary) got the 'bad drone frequencies' out by using a 'correct' Helmholtz device inside of the back box.

 

[TyphoonFiST]

I’d be really interested to see if someone can take some measurements on the Thermal

Measurements for what?

 

[rallytaff]

You can get silver exhaust paint to help protect it and delay rust.

The point to look out for with drone is ~2700-3200rpm under partial load - that's where you get the nastiest ~107hz droning.
If you could reply back here with how it sounds (or even some sound clips!) of part throttle under load from 2700-3200rpm (ideally, up a grade or something) that would be really handy.

You can get silver exhaust paint to help protect it and delay rust.

The point to look out for with drone is ~2700-3200rpm under partial load - that's where you get the nastiest ~107hz droning.
If you could reply back here with how it sounds (or even some sound clips!) of part throttle under load from 2700-3200rpm (ideally, up a grade or something) that would be really handy.

Many moons ago, in the UK, one of my uncles would soak his whole system in oil/paint mixture before he put it on his car. It would get burned off but he swore that his system lasted longer than normal.