'System ONE' is a unique ADJUSTABLE SOUND Muffler/Midpipe Combo!  Emissions Legal in ALL 50 States! for Fiat-124 , all
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'System ONE' is a unique ADJUSTABLE SOUND Muffler/Midpipe Combo! Emissions Legal in ALL 50 States!

2017-2020 · all

HELMHOLTZ Resonator for all the good sound you want. ADJUSTABLE SOUND midpipe with quick change resonator

Fits ALL versions of Fiat 124.

Optional Crosspipe!

PART NUMBER: 61-2349


Reg. Price: $1,299.00

Sale Price: $1,199.00



Free shipping offers apply only to destinations within US Lower 48.

Reg. Price: $1,299.00

Sale Price: $1,199.00



Free shipping offers apply only to destinations within US Lower 48.


System ONE Combines a unique Quad outlet muffler replacement with Helmholtz resonator to remove drone and a complete ADJUSTABLE SOUND Midpipe with Quick Change Magnaflow rockwool packed Resonator, all in 400 series stainless with full 2.5 inches diameter for best turbo performance, and polished Quad 3 inch tips! Plus made to accept optional High Flow Crosspipe for better turbo spool and hp, which is a separate cost item on this site (item 61-2348). System One is made exclusively for Good-Win Racing by Magnaflow, and should not be confused with the lower content non-adjustable and non-Helmholtz Magnaflow branded system also sold on our site (item 61-2216 on our site).

Unique Quad Tip Muffler Delete Section with Helmholtz Resonator!
Midpipe with Quick Change Ultra Efficient Magnaflow Resonator.
Fits QUAD TIPS to ALL models of the Fiat 124.


(1) Unique Helmholtz Resonator!. BIG Helmholtz resonator in the muffler delete section gives you all the lovely burble of muffler delete setups while cutting the drone you don't want by over 40db. Most all high end exotic sports cars include a helmholtz chamber built inside the stock muffler to edit the final sound carefully to lower drone, here our Helmholtz is MUCH bigger than stock setups to aggressively knock down drone so we can use far less packing material in the midpipe resonator (and none with straight pipe insert installed).

(2) ADJUSTABLE SOUND Midpipe with Quick Change Resonator! One of the reasons we call it System 'ONE' is that it answers the most popular question we get with our current RoadsterSport choices: should I get the RoadsterSport System with midpipe resonator, or without midpipe resonator? Now you don't have to make that choice because you have BOTH in the box, System ONE box includes a midpipe that has a small removeable section so you can add the included resonator when you want, and remove it when you want. Got a track day weekend or fun canyon cruise coming, add the straight pipe. Got a early work morning when you need to quietly exit the neighborhood, use the resonator. The resonator itself is about a foot long and uses Magnaflow's unique and highly efficient non fiberglass packing that is very efficient at sound suppression by weight. So when you want it wild, use the included straight pipe section for the midpipe. And when you want it mild, use the included Magnaflow resonator. Just single bolt V-clamps either side of the resonator make it easy to swap, see the video for best understanding of this feature.

(3) Fits ALL versions of Fiat 124! Another reason we call it System ONE is it is one system that fits ALL VERSIONS of the Fiat 124. Yes, it fits both Automatic and Manual Transmissions. Yes, it fits all trim packages: Abarth, Classica, Lusso. Yes, everyone gets big Quad Tips with the ONE!

What is NOT INCLUDED, BUT OPTIONAL: Magnaflow Crosspipe of 2.25 inch diameter that fits ALL versions of the car using System ONE (does NOT fit other Magnaflow systems), unlike our RoadsterSport brand 2.5 inch Crosspipe this optional Crosspipe is 2.25 inches only so it fits automatic and manual (see that Crosspipe which is item 61-2349 elsewhere on our exhaust page). That Crosspipe is the KEY item to making your turbo come alive! Makes your turbo spool faster and at much lower rpms than stock. Stock crosspipe is terrible for performance, starts at just 2 inches diameter and is pinched down to about 1.7 inches right at the inlet, which keeps your turbo from spooling quickly!

BRIAN'S APPLICATION NOTES: Our other RoadsterSport choices already include a lot of options plus flexibility to start with just the muffler delete and add midpipe and crosspipe later. So if we already make the BEST and only REAL highflow complete 2.5 cat-back exhaust systems, why start from scratch and do it yet again? Simple, we got to testing highflow downpipes... and that's where we noted we start to get some BOOMY DRONE in the mix. So we asked the question, and dared to imagine, what would the ultimate Fiat 124 system feature set designed from front to back would it look like if we did it with Magnaflow materials?

Unlike our other RoadsterSport systems you CANNOT buy just this muffler delete part of this setup, and you cannot buy just the midpipe part of this setup. Unlike our existing RoadsterSport systems where customers can start with muffler delete and later add the rest, here we started CLEAN sheet without concern for making anything backwards compatible with factory midpipe. Doing a complete system with none of the pieces backwards compatible with the cheapo flow limiting factory crosspipe, midpipe, muffler, means a true clean sheet design...or in this case CAD clean design.

Freed of constraints that come with making a muffler delete that will still mate to factory midpipe, we put everything where we wanted and gave the car precisely what it wants in terms of layout of a 2.5 inch muffler delete and midpipe combo. Result is best fit, design, function, and ultimately the best possible sound from a midpipe/muffler delete combo.

Why include a HELMHOLTZ CHAMBER? The helmholtz technology is a revolution in exhaust tech now in a Fiat 124 application. Our new HELMHOLTZ chamber muffler delete features an exclusive LARGE side branch resonator that massively reduces the standing wave drone 'boominess' that comes with a muffler delete that carries 2.5 inches of flow all the way from the turbo downpipe outlet. The Helmholtz chamber cuts the 'booming' frequencies of 120-130hz by about 40 db inside a top up Fiat 124 cabin which is a common source of complaints with aftermarket ultra high flow exhausts. Result is all the FUN throaty sounds you want, and no boomy drone!

Why not just use a mechanical valve and bypass at full throttle? The use of mechanical valves is popular in OEM exhausts right now, but this gimmick has come with many downsides that include highest failure rate of just about any part on the car. The valves live under the car in a harsh environment and they get coated in crap and they eventually stick and fail and become a common service complaint. The other downside with such valves is you get all or nothing....all the sound can be too much for many, and fully valved into a muffler can mean too on/off, too schizophrenic. If you want fun sound that builds in a linear manner in direct proportion to what your right foot does, then you don't want a valve.

With the Helmholtz chambers we use the neck to the Helmholtz as the valve to the tuned chamber, essentially an air valve that can never stick or fail. Moreover, with a Helmholtz chamber we can tune out just the frequencies we want to trim down, leaving all the fun exotic burble without the boom/drone downsides.

We also sell the Magnaflow branded muffler/midpipe combos on this site but they are just standard muffler and midpipe, no crosspipe option, no downpipe option, no helmholtz chamber to kill drone. Thus, performance is far from ideal in our view. More issues include that they use a ton of their high density non-fiberglass sound packing in a very large muffler, which is VERY effective at killing upper frequency, but results in a sound spectrum analyzer reveal an extremely limited dynamic range out the tail pipe. What does that mean? Imagine those times when you are trying very hard to listen to a really boring person on stage give a lecture, how hard is it to pay attention and appreciate what they are saying when they speak in a low constant monotone? You can just feel yourself going to sleep in the lecture right? Similar situation with the standard Magnaflow muffler/midpipe combo, they use so much packing material that it absorbs all the upper frequency fun these motors can make, leaving a rather boomy monotone low frequency drone that lacks dynamic character and variation. That result is not offensive, in fact it's exceptionally well controlled.... but boring as hell if you compare side by side with what we have here.

The advantage of working with Magnaflow here is that we can use a more measured amount of that super effective high density packing they specialize in, we put it in the midpipe area, combined with our experience with helmholtz chambers, to shape a sound result that is far more frequency customized. The sound is much more dynamic, interesting, exotic (baby maserati), and laugh out loud fun!

Downsides: all our RoadsterSport brand systems are higher grade higher cost all polished 300 series stainless end to end. Like other Magnaflow products, this SystemOne is almost all 400 series stainless so we don't bother to polish it all (the gorgeous quad tips are still 300 series with full polish because that's the only part you see regularly). The 400 series stainless will develop a thin rust coat immediately, though upside is both less cost and higher carbon content for even more strength so it will easily outlive the life of the car.

INSTALL TIP: Notice the flanges on the removeable midpipe resonator/straight pipe are asymmetrical, how you put that piece in makes a difference in pulling the entire midpipe toward the driveshaft or pushing it away from the driveshaft. So, twist that section in place before you lock it down and watch the effect on lay of the midpipe. Do NOT use header wrap on Crosspipe, it will create a fitment issue and degrades the stainless material.

Video below from driver's seat and rear bumper, both with resonator installed (not having it installed raises the volume but doesn't change the character).

Customer Jacey Cobb's install of our complete 'System One' exhaust leaving the starting line at BMW Club Autocross Event! This is with the quick change resonator the optional Crosspipe.

Fantastic Installation Video by our dealer and friend Bryan at NGEN Customs and Performance:

Customer install of basic "SystemOne" with stock crosspipe, and the removeable straightpipe section installed.

with resonator installed instead of straight pipe:



Customer Reviews

'System ONE' is a unique ADJUSTABLE SOUND Muffler/Midpipe Combo! Emissions Legal in ALL 50 States!

This review is written based on a 3100 mile 2018 Abarth 124 Spider Right Hand Drive.

Had to replace the Record Monza because the RM valve was seized (common rust problem) and RM has too much drone when cruising. Ordered 2.25" Downpipe + straight midpipe + System One and they arrived quickly in good shape after crossing the Pacific Ocean.

I asked my friend who own a pro exhaust workshop to install it for me.
The removal part that was tricky. Use plenty of rust penetrating oil. Still, one of the 2 bolts connecting the catalytic converter and downpipe was corroded and broke. It took my friend 2 hours to remove the cat to take the stuck bolt out in his workshop so DIY guys please take note if your car had been driven in snow.

Installation of System One was straight forward. Everything fit perfectly. No welding is needed, just nuts and bolts.
Results: About the same tone and loudness as a Record Monza. Drone is completely gone. Car is much more responsive from stand still to red line.

It is a quality product I would highly recommended it.

Holy crap it sounds amazing!! I was concerned it would be too loud, even with the resonator since I have a 3" downpipe with high flow cat. The car actually purrs now, and only screams when I step on it. I previously added sound mat to my trunk to cut the noise with the top up, and there is even less annoying drone with this exhaust compared to stock. The true test however was that when I pulled in to the garage my fiance (who "doesnt understand all this car stuff") said wow, I love the sound of it!

Excellent product. Love it. Customer service from Goodwin Racing is unmatched and outstanding.

System one is a great deal. You get a lot for your money. I love it. The only product in a reasonable price range out there that could make me forget i never got the record monza. It's better. high flow performance plus the options you get with the resonator and v band clamps? it's a great deal and i can't believe every spider owner doesn't already have one. Highly recommend

Bought the system one and a crosspipe for my AT lusso, it came in quick with high quality packing materials.
All of the pieces crafted well, the tips out the back make it look like an actual sporty car.
Put a little over 500mi the first week with the resonator in, sounds amazing cruising on the highway and zipping around town.
Didn't want to leave the straight pipe sitting around, so I tossed it on before work(about 10minutes with manual tools in dress clothes)... it audibly is louder and more throaty than the resonator. I've been running it for over 1000 miles on the straight and love every second the car is on. If sound levels aren't a problem in your area, I would recommend it over the resonator...but if you aren't into a louder exhaust(have passenger) the resonator hits the right spot with the added helmholtz.

Absolutely no issues, such a beautiful system audibly and visually.

I did a DIY install of the cross pipe and System One Exhaust. Posted the full review with some pics on the 124Spider dot Org site.


Quick Delivery, well packaged, great fit, high quality, easy install with no issues at all, awesome support.

Performance improved, low end in particular but not dynoed or measurement road tested. Just seat of the pants assessment.

Noticed system is 12 lbs lighter the stock which is an extra plus in a low HP Lite Weight Car.

With the straight pipe, sound is deeper and more consistent then the axle-back I had on previously. Sounds like a more larger more powerful engine. Also there is no drone at all at highway plus speeds. I paired this with the 2.25" Cross-pipe.

This is an excellent system. The fit and finish is superb. Even the muffler shop commented on how high the build quality was and how they did not have to adjust any of the mounts for a perfect fit. Bolt it on and go. The straight pipe was a bit loud so I installed the resonator. It has awesome deep-tone sound for everyday driving but I do miss the "rowdiness" of the straight pipe. I can see lots of trips under the car switching that pipe for special events.

Love, love, love System One. I'm running with the OEM downpipe and (for now) crosspipe and the sound is near perfect for what I'm looking for. With the straight pipe in, it's louder, but not so much you're going to fall out with your neighbors. With the resonator in, there's enough extra noise when on throttle to be fun, but near OEM sound levels at all other times - perfect for date nights...

I was recently able to drive my car with the straight pipe in back-to-back with a car with the full resonated RoadsterSport set up, including the sport cat. While the noise levels from both cars was essentially the same to the naked ear, and both are a lot of fun, we both agreed that the noise from the System One set up was more refined.

One last thing - the Helmholtz chamber is magical. I drove 280 freeway miles with the straight pipe in at the weekend and while the sound is higher than stock at cruise, it's neither unpleasant or tiring with no boomy resonance. With the roof down at freeway speeds, wind noise will still be the predominate factor. Roof up, you'll be able to listen to music or hold a conversation as easily as with an OEM set up.

This has to be one of my favorite mods.

My wife wanted a two seater sport car, after looking at the Lusso vs the Abarth, the price difference and the sound that came out of the Abarth was not worth paying for.
After 30 days of ownership, she wanted more power and a little rumble, so we ordered the complete System ONE kit along with the cross-over pipe, and a new DV+ Diverter Valve.
The System ONE kit and the DV+ from Goodwin Racing were well packaged and arrived without damage, and as expected had the magnaflow sound bits inside.
Now I am a Jeep shop owner, so after the installation of the entire system (used the resonator), which went extremely well (maybe an hour), I was apprehensive about the startup and what the exhaust would sound like from the little 1.4L, well I can tell you it's not a V8, but is sure not a ricer, it had a deep throaty european sound. The wife enjoyed the sound. Took it around the block and you could feel the turbo lag had pretty much disappeared. Added the DV+ and the Turbosmart 7+ actuator and now its a little performance car and as she puts it the Beamers hate her now. I highly recommend this kit to any one who want to add a little performance and a performance sound to their Fiat 124 Spider.

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