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- The Flowmaster Original 40 Series Muffler takes the checkered flag as Flowmaster's most aggressive-sounding muffler
- Crafted from aluminized steel for corrosion resistance and precision mig welded for maximum durability
- Perfect for early muscle cars, off-road & race vehicles and dual-exhaust rides
- Hear the power of your engine with the excellent interior resonance of the 40 Series—especially at 1800-2000 RPMs and again at 2400-2600 RPMs
- Original two-chamber design maximizes horsepower and torque
- The centerpiece muffler for many Flowmaster American Thunder Exhaust Systems
- Casing embossed with the Flowmaster name
- Your Flowmaster Original 40 Series Muffler carries a 3-year warranty
Get the original aggressive Flowmaster sound that puts serious punch into your vehicle's presence and power. The Flowmaster Original 40 Series Muffler maximizes horsepower, torque and flow with its two-chamber design-the original two-chamber Flowmaster muffler.
If the roaring sound of an engine is music to your ears, you'll love the Flowmaster 40 Series. Aggressive sound is maximized outside, while high-volume interior resonance lets you hear every push of the pedal. It's this total sound design that makes the Flowmaster 40 Series the centerpiece of many of Flowmaster's outstanding American Thunder Exhaust Systems.
Ideal for early muscle cars, off-road rides and dual exhaust cruisers, the Flowmaster Original 40 boasts the quality construction you'd expect from Flowmaster. Each Flowmaster muffler is built with 16-gauge aluminized steel for corrosion resistance and fully mig-welded for maximum durability. Best yet, your Flowmaster Original 40 Series Muffler boasts a 3-year warranty.
- Flowmaster Original 40 Series Mufflers come in a variety of inlet/outlet configurations and sizes, shown above. Select the inlet/outlet diameter you need from the drop down at right.
Flowmaster Original 40 Series Mufflers Customer Reviews
77 Customer Reviews
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Reviewed by Jordan A (NARRAGANSETT, RI) Reviewed for a 2008 Subaru Impreza — Sep 17, 2015 9:16 PM
I ordered these to put on my 08 Subaru Impreza and it gave it an amazing sound. I needed new piping to adjust to the size of the inlet and after it was done the sound came put great!
Reviewed by Christopher B (PLANO, TX) — Aug 28, 2014 8:17 PM
The 40 series has a very aggressive deep sound, I freaking love it! It does have some drone but it's not bad
Reviewed by Larry B (Garden City, KS) Reviewed for a 1990 Ford F-450/550 — Mar 01, 2014 6:20 AM
Best thing I can say about the Flowmaster is that it was made in the USA. Good product; easy install, affordable, got to me in reasonable amount of time. Thanks