Advice on different types of Flowmaster mufflers. Details about two chamber Flowmaster mufflers and Flowmaster straight-through muffler designs. Also pictures and links to sites that sell the Flowmaster mufflers featured.

The Flowmaster sound is the true tone of American muscle and performance. Available in a wide range of domestic and import applications for automobiles and trucks. Flowmaster mufflers produce more power than OEM and competitive aftermarket products.

What makes a Flowmaster muffler so unique is that its performance improvement is paired with their unique exhaust tones. The "Flowmaster Sound" is offered in many different tones depending upon the muffler series. From the deep, aggressive tone of the Flowmaster mufflers 40 Series to a quiet and subtle, but unmistakably rich Flowmaster tone of the 70 Series, you will find the right application of performance and exhaust sound you want.

Standard 40 Series - Two Chamber Flowmaster Mufflers

This is the most "aggressive" sounding street/strip muffler that Flowmaster offers. If you're looking for attention, this one will get you noticed. The standard 40 series has an "aggressive rumble" and will generally resonate inside the vehicle around 1800-2000 rpm's, and again at 2400-2600 rpm's. Constructed of 16 gauge aluminized steel and fully mig-welded for maximum durability.


The American Thunder 40 Series is the most aggressive sounding street and strip muffler in Flowmaster's product line. The 40 Series will generate extreme interior resonance within the vehicle. If you want to really hear your exhaust system inside as well as outside your vehicle the 40 Series is for you.

Application Recommendations:

Off Road and Race applications
Early Generation Muscle Cars
Vehicles with dual exhaust

The Super 40 is our latest development utilizing "Gen II Delta Flow" technology. This gets you the best of both worlds of Sound and Performance. The Super 40 has that "deep powerful" sound of the original 40 series but with all the benefits of performance and low interior resonance from the "Delta Flow technology."


The Super 40 5X10-inch case design, modeled after our Top Ten race Flowmaster mufflers, gives you a deeper tone that retains our famous 40 Series sound and feel. Our Super 40 is the most aggressive, deepest sounding street 2-chamber muffler. The classic black case maintains that original Flowmaster mufflers look.

Application Recommendations:

High horsepower street cars
Reduced Interior Resonance
Increased flow path radius
Vehicles with dual exhaust

This internal tubing is generally reduced as it enters the inlet of the muffler to help achieve a further reduction of sound as its exiting the muffler, smaller hole, less sound. At the same time this creates a further restriction for hot exhaust gases traveling through the mufflers.