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Doug Thorley Headers

Doug Thorley Headers Cat-back Exhaust, Axle-back Exhaust, Headers, Mid-Pipes and Exhaust Products

 

For over 60 years, Doug Thorley Headers has been an innovator in the automotive aftermarket. Driven by a passion for performance headers and superior quality exhaust systems, Doug Thorley Headers is committed to developing 100% American-made products that will reliably deliver maximum horsepower and torque. Doug Thorley Headers has been pushing the limits of automotive technology since first inventing the Tri-Y Header in 1958, and they do it all on American soil.

Every vehicle model is unique, and the Doug Thorley R&D team is constantly working to provide a diverse range of products and applications to meet demand. Whether you are hauling an RV, building up a street hot rod, or just looking to get a little more punch out of your Smart Car, Doug Thorley Headers has the best performance headers to maximize horsepower and torque for your application.

Why the Tri-Y? Serious Horsepower, that’s why!  Invented by Doug Thorley Headers, the Tri-Y header is designed to match the synchronization of the engine firing order, thereby maximizing exhaust scavenging. This design creates the optimum torque and greatest horsepower gains in comparison to any other design.

Doug Thorley Headers operates under the principles of meticulous attention to detail and unmatched craftsmanship while their experienced staff continues to lead the way in automotive performance. Accesspeed is proud to offer Doug Thorley Headers products to our customers. With our low price match guarantee, you will always find the best combination of price and selection at Accesspeed.

 

Below are some of the Doug Thorley products offered by Accesspeed:

Short Tube Headers

Mid-Length Headers

Long Tube Headers

Sandrail Headers

50-State Legal Headers

Cat-back Exhaust

Axle-back Exhaust

Mid-Pipes

 

 


Exhaust, Mufflers, Headers and Tips » Cat-Back Exhaust

Cat-Back Exhaust Systems

 

What is a cat back exhaust system?

A Cat-back exhaust is the section of the exhaust system that runs from the outlet of the catalytic converter to the exhaust tips. Cat-back exhaust systems can improve horsepower and fuel economy, as well as changing the exhaust sound to something more aggressive, and often includes all pipes from the catalytic converter to the tips, including mufflers and/or resonators.

 

Is a cat-back exhaust legal?

Yes. Cat-back exhaust systems are legal, as they are installed behind the catalytic converter (hence, cat-back) and do not modify or remove emissions components. Additionally, cat-back exhaust systems are Federally protected under the Magnuson-Moss Warranty Act, and will not void your factory warranty.