This Magnaflow xMod Exhaust Made My LS3-Swapped Wagon Sound INSANE!
Tuning a custom, drone-free exhaust for LS3-powered B-Bodies is a challenge, but this Magnaflow xMod system absolutely rocks! (LS3 Roadmaster Wagon Project | Part 7)
To recap, thus far we’ve added a new coilover suspension; swaybars, wheels, and tires; new brakes; and swapped out the original 5.7L TBI iron block V8 for a Chevrolet Performance LS3 E-rod Connect & Cruise System with Holley accessories. And now it’s time for an exhaust. Fortunately, Magnaflow invited us down to its Ocean Side, California headquarters to install a new Magnalfow xMod system and tour the facility.
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Magnaflow xMod Mufflers
José, Magnaflow fabricator
Magnaflow first developed the xMod series of mufflers and catback systems for specific vehicles like Mustang and Camaro. The idea? Allow customers to pick the exact tone and volume while fighting drone and NVH. How does it work? xMod mufflers typically include not one, but two exhaust outlets. A quiet side, which is always open, and a loud side, which can be capped or left open for extra oomph.
xMod systems also include Magnaflow’s No Drone Technology, which utilizes quarter-wave noise-canceling principles to target and reduce drone at its most annoying frequencies. For vehicle-specific xMod mufflers, Magnaflow does extensive testing to tune the system to a particular drivetrain.
The Universal xMod mufflers are similar, but a little different.
Available in both 2.5-inch and 3-inch sizes, universal xMod mufflers look like other Magnaflow single inlet / dual outlet mufflers. The straight-through side is quiet; the other is louder. And then it’s up to the customer to install one of the included accessories on the loud side–
- J-pipe
- Resonating chamber
- Cap
- Exhaust turndown
Customers can install both the J-pipe and the chamber or the cap. Or they can place the chamber or cap directly onto the muffler outlet. Or simply install the turndown. The J-pipe can also be cut to a specific size to fight certain drone frequencies. For a stealthy, quiet experience that growls during acceleration and minimizes drone, pick that J-pipe and the chamber or cap. For a throatier rumble, just use the turndowns.
The Magnaflow Experience
While José and the Magnaflow team were working on the Roadmaster xMod install, Magnaflow Senior Manager Richard Waitas (pictured above) gave us an in-depth tour of their facility. Everything at Magnaflow is designed and produced and distributed in-house.
Our project was in the research and development center, where Magnaflow brings in vehicles for produced testing and design. It turns out that most of Magnaflow’s business actually comes from catalytic converter systems, so you’re likely to find a collection of aging polluters outside waiting to be scanned into 3D digital space.
Magnaflow then uses computers to design and build new parts (cats, mufflers, full exhaust systems, and accessories), and then tests them out to make sure everything works as it should. Once a prototype is working well, Magnaflow creates what they call a “fixture” — which is effectively a metal template to ensure all future copies are exactly the correct size.
Products then become part of Magnaflow’s massive production process, which is all organized by very smart people running algorithms to calculate how many parts they need to produce for particular vehicles. (Plus, of course, their various universal components). Magnaflow production is a combination of old-school and high-tech factory processes, a mixture of humans and robots and massive machinery.
All of it organized by those very smart people with algorithms to keep things as efficient as possible.
At the end of the day, Magnaflow ships over 2 MILLION products annually, all of them made and assembled right here in the USA.
Goodbye, Drone
The big challenge with tuning custom exhaust systems is that you’re dealing with a powertrain that was never engineered to be in a particular vehicle. In our case, the LS3 tends to drone at certain speeds and transmission gearing. And Roadmasters are 19-feet of steel, plastic, and glass surfaces that love to hum and vibrate.
So, Drone x Drone = DROOOOOOONE.
Fortunately, we had Magnaflow’s help. Overall, the Magnaflow xMod system did a nice job of eliminating drone. Anything below 70mph was pretty darn quiet. But to achieve this, the overall volume was also a little too quiet for my tastes. (With the LS3 E-ROD, we have 4 catalytic converters in addition to 2 mufflers.) And we were experiencing some vibration at tip-in.
So we chatted with Magnaflow about what causes NVH — in this case, polyurethane engine and transmission mounts — and the best way to fight drone. Turns out that drone-canceling works better if it’s placed as forward as possible in any given system. Magnaflow suggested flex joints as well as Helmholtz chambers (which work like the J-pipes).
After a recommendation from a professional LS3 E-ROD installer, we ended up contracting Luis at 3C Performance Exhaust in Los Angeles, CA to install the flex joints and Helmholtz chambers just after the cats. He also installed active valves on the xMod mufflers, which allows me to open and close the loud-side exhaust turndowns so I can go from mild to wild at the press of a button.
To be clear, this exhaust isn’t going to blow the doors off at your local cars and coffee.
But as you can hear in the video up at the top (exhaust clips are near the end), it sounds pretty great when you get on it. The drone is 99.9% gone. And we don’t have to worry about California cops pulling us over for noise-ordinance (or emissions) violations. For a family cruiser, it’s a big win and sounds even better in person.
Huge Thanks!
To José and Richard and everyone at Magnaflow for helping out on the project and for allowing me to see all of the amazing work that goes on in the Magnaflow HQ.
Next Up…
We’re off to visit the largest Chevrolet Performance dealer in California, installing Dakota Digital Gauges, and going to pass our very first California SMOG test!
LS3 Roadmaster Wagon Project EPISODES
Part 1
Parts & Project GoalsPart 2
Michelin Tires, American Racing Wheels, Eaton TrueTrac, & Sway BarsPart 3
Wilwood D52 Disc BrakesPart 4
Coilovers & Control ArmsPart 5
Goodbye TBI, Hellow Earl’s Vaporguard Fuel SystemRacingJunk.com Bonus
Everything You Need to START a Chevy Performance Connect & Cruise System
(LS and LT Engines)Part 6
Installing an LS3 E-ROD & Holley Accessories in a Roadmaster Wagon!!!Part 7
This Magnaflow xMod Exhaust Made My LS3-Swapped Wagon Sound INSANE!Part 8
Dakota Digital: LS Swap Gauges & Wiring Made Easy! (Plus Guaranty Chevy & Chemical Guys!)Part 9
LS Swaps Are a LOT More Expensive Than You Think!!!Part 10
10 Tips for Surviving Your First LS SwapBonus
Every Part You NEED For Your First LS SwapClick HERE to join the LS3 Roadmaster Wagon Project BUILD THREAD!
PARTNERS
- Guaranty Chevrolet: https://www.occhevy.com/
- Holley: https://www.holley.com/
- Magnaflow: https://www.magnaflow.com/
- Chemical Guys: https://www.chemicalguys.com/
- Dakota Digital: https://www.dakotadigital.com/
- Michelin: https://www.michelin.com/
- Wilwood Brakes: https://www.wilwood.com/
- Eaton: https://www.eaton.com/
- Sony: https://electronics.sony.com/
DISCOUNTS PROVIDED
- Summit Racing: https://www.summitracing.com/
- Muscle Rods aka BRP HotRods: http://www.brphotrods.com/
- Sikky Manufacturing: https://www.sikky.com/
- American Racing Wheels: https://www.americanracing.com/
