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 » Down-pipes
Down-Pipes
What is a down-pipe?
A down-pipe is an exhaust tube that directs the exhaust gases from your vehicle's turbo “down” into your exhaust system. The downpipe typically bolts onto the exhaust side of your turbo housing, and connects at your mid-pipe section. Some down-pipe exhaust brands include catalytic converters and others are simply straight-though pipes that bypass and/or eliminate the catalytic converter.
Does a down-pipe make your exhaust louder?
Yes. Most aftermarket down pipes have a straight-through design that will reduce backpressure and increase exhaust efficient. This makes your exhaust louder with a more aggressive note.
Does a downpipe increase horsepower?
An aftermarket down-pipe on any turbocharged engine should increase horsepower. In most cases, the upgraded down pipe will allow the turbo to spool quicker and hold a higher boost level.
Does a downpipe increase fuel economy?
Like most upgrades that reduce backpressure and allow exhaust gasses to exit more efficiently, you can realize a fuel mileage gain. However, most Accesspeed customers are simply unable to keep their foot out of the throttle long enough to see the fuel economy improvement.
Are down-pipes legal or illegal in my state?
If a down pipe requires modification or removal of the OEM catalytic converter, it is likely not legal. If the down-pipe you want to order is not 50-state legal (CARB-approved) with a proper EO#, it is most likely illegal in your state. We recommend checking your state laws to verify prior to purchasing.