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  • Monday to Friday: 8 a.m. - 6 p.m. ET
  • Saturday/Sunday: Closed


  • Monday to Saturday: 8 a.m. - 12 a.m. ET
  • Sunday: 9 a.m. - 5 p.m. ET

Flowmaster 50 Series Delta Flow Muffler 842453

Product Information
List Price:
Our Price:
5 (1 review)
Part #:
T-409 Stainless Steel
Inlet Style:
Opposite Side Offset Inlet & Outlet
Outlet Dimensions:
2.25" Inlet & Outlet
2.25" Inlet / 2.25" Outlet (Offset In - Offset Out) Opposite Side Offsets
  • 17" muffler
  • 4" x 9.75" body
  • Moderate sound
  • Features advanced three-chamber design
  • Compact exterior case size muffler was especially designed for passenger cars rather than trucks or SUV's


  • Deep, Moderate Tone: The 50 Series Delta Muffler from Flowmaster offers a moderately deep tone that sounds great. It is designed for street or strip vehicles including cars, trucks, and SUVs.
  • Delta Flow Technology: Flowmaster's Delta Flow Technology ensures optimum performance without excessive resonance. The 50 Series Delta Flow muffler offers reduced interior tone levels for a comfortable ride.
  • Improved Exhaust Flow: The 50 Delta Flow muffler features a specially designed Resonance Tuning Chamber that offers improved flow of exhaust gasses through the muffler for increased performance with reduced interior resonance.
  • Stainless or Aluminized Steel: Choose from either 409 Stainless Steel or Aluminized Steel. Flowmaster 50 Delta Flow mufflers are available for 2", 2.25", 2.5", and 3" exhaust systems.
  • Made in the USA - Santa Rosa, CA

The Flowmaster 50 Series Delta Flow mufflers are intended to be used on most cars, trucks, and SUVs. They are designed for greatly reduced interior resonance with a moderate exterior tone with a great sound. The 50 Delta Flow mufflers feature a slightly smaller case size and specially designed Resonance Tuning Chamber. This allows for the same great Flowmaster performance without the increased interior sound. 50 Delta Flow mufflers feature a case size of 17"L x 9.75"W x 4"H with an overall length of 23". They are available in aluminized or stainless steel finishes and are designed for 2"-3" exhaust systems.

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California Residents: Prop 65 Warning

Frequently Asked Questions

What is Flowmaster's warranty? All Flowmaster products built of aluminized steel have a 10 year limited warranty against defective materials and workmanship. All stainless steel mufflers have a 10 year limited warranty against defective materials and workmanship.

What is "Delta Flow" technology?
Flowmaster's "Delta Flow" technology has evolved from extensive Research & Development at race-tracks around the country. This new technology provides superior scavenging while reducing resonance inside the vehicle. What you can expect is improved performance while maintaining a pleasant tone, both inside and outside the vehicle.

What materials are used to build Flowmaster mufflers?
All Flowmaster products are fully mig welded and built from 16 gauge aluminized steel for durability and value. Specific part numbers of the 40 and 50 series are also offered in 409 stainless steel, while the Hushpower II mufflers are offered in either 409 stainless steel, or 304 stainless steel.

What pipe size should I use for a street application?
In general, the following guidelines should be applied for street applications.

2" tubing up to 100 HP per pipe
2.25" tubing up to 160 HP per pipe
2.5" tubing up to 200 HP per pipe
3" tubing up to 300 HP per pipe 
What is the difference between a 40 series and a 50 series muffler?
Both mufflers have the same sound outside the vehicle, but each has varying sound levels generated inside the vehicle. The 40 series (two chamber) will resonate inside the vehicle, generally around 1800-2000 rpms and also again around 2400-2600 rpms. The 50 series (three chamber) incorporates an H-chamber that helps eliminate this interior resonance in the cab area of your vehicle.

Will I lose power going from a 40 series to a 50 series, or to a 70 series?
No. Flowmaster engineers each series of mufflers for very low restriction with the main differences being varying sound levels both inside, and outside your vehicle. This way you can customize your vehicles sound levels to your vehicles needs and sound preference.

Do I need to install an "H" pipe to my dual exhaust?
Flowmaster strongly recommends using an "H" pipe, commonly known as a "balance tube" on all "true dual" exhaust systems. An "H" pipe equalizes the pressures between both banks of the engine giving a broader and flatter torque curve throughout the rpm range. It also eliminates "back-rap" common on deceleration, and creates a deeper mellower tone both inside and outside of the vehicle.

Is an "X" pipe better than and "H" pipe?
Over the years, Flowmaster's testing of all types of crossovers, including "X pipes", has revealed no substantial benefits over a properly installed "H" pipe on street driven applications. However, in race applications with small cubic inch engines and /or restricted (small bore) carburetors, will respond well to the addition of X pipes, tri-y styled collectors and/or properly designed single exhaust systems.

Will my late model vehicle run better if I replace the single inlet muffler with a true dual exhaust system?
Flowmaster does not recommend replacing factory single inlet exhaust systems with a "true dual" system on computer controlled vehicles. The computers in most late model vehicles will not be able to compensate with the fuel needed with an almost doubling of the exhaust flow. Flowmaster’s dual outlet kits will give you the look of a "true dual" system, while optimizing the vehicles performance.

Do I need to run tailpipes after the mufflers?
Yes, Flowmaster highly recommends running tailpipes out from under the vehicle. This directs the exhaust fumes away from the vehicle, while minimizing the sound transmitted into the cab area of the vehicle.

What kind of performance gains can I expect when installing Flowmasters on my vehicle?
Performance gains will vary dependent upon your application. The more power the vehicle makes, the bigger the gains will be. Generally, a 5-7% gain of power is fairly typical, while 1-2 mpg can be achieved. That is if you can keep your foot out of the gas to hear that Flowmaster sound.

How can I be sure that I'm buying a Flowmaster muffler?
The Flowmaster name is embossed in every muffler case that Flowmaster builds. If it doesn't say Flowmaster on the case, it's not a real Flowmaster muffler.


Watch This Video
Flowmaster Exhaust Technology Explained - Chambered Technology 101


Product Reviews Summary

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Part #: FLM-842453 Posted on
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(Flossmoor, IL)
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Ease of Installation
I am extremely happy with the product I purchased from Real Truck. The young lady in sales that assisted me with my purchase was outstanding and went above and beyond the normal level of customer service offered by other companies. She was very helpful and I really appreciate that. My 5.0 STANG is now growling and prowling the streets of Chicago.

Frederick White


Lifetime Warranty SS / 3 Year Warranty Aluminum

Flowmaster is offering a lifetime limited warranty on their stainless steel 50 Series Delta Flow Mufflers and a 3 year limited warranty on the aluminum 50 Series Delta Flow Mufflers.


Flowmaster mufflers are designed to work with new or existing exhaust systems.  They offer slip on installation and can be welded or clamped into place.  Due to the use of heavier materials, Flowmaster recommends spot welding the joints when using clamps.  On some applications it will be necessary to cut or splice when adding Flowmaster mufflers to an existing exhaust system.