Get the original aggressive Flowmaster sound that puts serious punch into your vehicle's presence and power. The Flowmaster 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 40 Series 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 40 Series Muffler boasts a 3-year warranty.
Flowmaster 40 Series American Thunder 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.
Return Policy
Returns; Defective and Damaged Merchandise
Defective and freight damaged merchandise (but only where FlowSeriesExhaust.comis providing shipment) may be returned to FlowSeriesExhaust.comfor full credit, but only upon verification by FlowSeriesExhaust.comof such defect or damage. A Returned Merchandise Authorization ("RMA") form must be filled out by the Buyer and Approved by HyperTechPowerChips.com. Credit will be issued to Buyer upon receipt of the RMA form and the claim approval from the freight company.
Returns; Exchanges; Good Merchandise
Returns of good merchandise may be accepted by FlowSeriesExhaust.comin its sole discretion under the following conditions:
Return/Exchange of merchandise in totally re-saleable condition, without markings on the original packaging will be restricted to extraordinary circumstances with prior approval from HyperTechPowerChips.com. Accepted return will be assessed a 25% restocking charge. Returned part number shall not exceed 15% of total annual purchase quantities.
Return/Exchange of merchandise in packaging that has been marked, relabeled or otherwise defaced will be restricted to extraordinary circumstances with prior approval from your HyperTechPowerChips.com. Accepted return will be assessed a 30% restocking charge, except that FlowSeriesExhaust.commerchandise returned in packaging that has been marked, relabeled or otherwise defaced will be subject to a 40% restocking charge. Returned part number shall not exceed 15% of total annual purchase quantities.
Merchandise classified by FlowSeriesExhaust.comas TB (To Be Discontinued), or DC (Discontinued), may not be returned for credit.
Merchandise on sales promotion or inventory packages may not be returned for credit.
Buyer must pay all return transportation charges.
Buyer must obtain and complete an RMA form, issued by HyperTechPowerChips.com, for any good merchandise return or exchanges.
Returns/Exchanges will not be accepted under any circumstances after 15 calendar days after the ship date indicated by HyperTechPowerChips.com.
Any returns for non-fitment or quality issues will require high quality digital pictures of the products to be emailed to the account manager before an RMA is approved.
Order cancellations will take up to 48 hours after a cancellation is requested before the order is officially cancelled and money processed for return.