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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
85 Customer Reviews
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Reviewed by Chris N (Las Cruces, NM) Reviewed for a 2016 GMC Sierra — Wednesday at 7:53 AM
I installed this by removing everything from the stock muffler back. Installed the series 40 exactly where the original muffler was and had exit pipe turn out just in front of the rear tire. Unless you were in the throttle really hard, you couldnt tell if it was a V8 or the V6.
Reviewed by Edward H (BELLMORE, NY) — Wednesday at 7:12 AM
basically you know why you want this item, you want sound and notice abilities. You will get that with this product. This is a great product, I fully stand by flowmaster, I've had flowmaster for 25 + years and it's a great feeling each time. Big thanks to flowmaster.
Reviewed by James W (EDMONDS, WA) Reviewed for a 2001 Nissan Frontier — May 10, 2018 9:28 AM
I got the pipe diameter and size of the original muffler, then ordered this one based on required size. The original system was stainless and both pipes were in very good shape, so I was looking for a replacement muffler that as not going to break the bank. The vehicle is 18 years old, so the only other parts that I found were CAT-back with both pipes included priced almost 6X the muffler alone. The old muffler was cut out and this one welded in, and the system is good as new.
Reviewed by John S (TENNESSEE COLONY, TX) Reviewed for a 1993 Chevy C/K 3500 — Feb 07, 2018 6:33 PM
I just replaced my original flowmaster after ten years of use and it sounded great and so does this new one!!!!!
Reviewed by Stan G (Lawrenceville, GA) Reviewed for a 2008 Dodge Ram — Dec 19, 2017 9:04 PM
Since I add the 40 series Muffler to my Dodge performance is much better I actually can feel it when I accelerate.