SLP

SLP Performance: Engineering Heritage Meets Modern Muscle

Street Legal Performance (SLP) has been a driving force in American muscle car performance since 1987. Founded by drag racing veteran Ed Hamburger, SLP earned its reputation by working directly with General Motors to create factory-authorized performance packages that transformed legendary vehicles like the Pontiac Firehawk and Camaro SS into modern muscle car icons.

The SLP Loudmouth Legacy

SLP revolutionized aftermarket exhaust technology with its signature Loudmouth series, featuring innovative resonator designs that deliver dramatic power gains and an unmistakable aggressive tone. The Loudmouth system replaces traditional mufflers with specially engineered resonators, creating virtually zero flow restriction while producing gains of up to 25 horsepower depending on application.

Modular Technology for Complete Control

SLP's groundbreaking modular exhaust design allows enthusiasts to customize their sound profile by swapping between Loudmouth resonators, Loudmouth II bullet-style mufflers, and PowerFlo traditional mufflers in minutes—no welding required. This flexibility means you can dial in everything from track-ready aggression to more civil street manners.

Popular SLP Exhaust Applications

Chevrolet Camaro: From third-generation F-bodies (1982-2002) through fifth-gen and sixth-gen models (2010-2017), SLP offers complete cat-back and axle-back systems engineered specifically for LT1, LS1, LS3, and LT1/LT4 applications.

Ford Mustang: SLP Loudmouth systems for 1999-2004 Mustang GT and Mach 1 (4.6L), 2005-2010 GT and GT500 (4.6L/5.4L), and 2011-2014 GT and GT500 (5.0L/5.4L/5.8L) models deliver that iconic American muscle rumble with proven dyno-tested performance gains.

Dodge Challenger/Charger/300C: Purpose-built for 5.7L HEMI R/T models (2008-2014) and SRT-8 applications with 6.1L/6.4L HEMI engines (2005-2014), featuring 3-inch mandrel-bent stainless steel construction and integrated PowerFlo-X crossover technology.

Corvette: Premium exhaust solutions for C5, C6, and C7 generations, maintaining SLP's commitment to engineering excellence on GM's flagship performance platform.

GM Trucks & SUVs: Specialized systems for Silverado, Sierra, and full-size SUV applications bringing muscle car sound to work vehicles.

Premium Construction Standards

Every SLP exhaust system features mandrel-bent stainless steel tubing (typically 2.5" to 3" diameter depending on application) for maximum flow efficiency and corrosion resistance. Show-quality polished tips with electromarked SLP logos, pre-welded hangers, and complete hardware kits ensure professional installation and lasting appearance.

The OEM-Quality Difference

As the first company to develop 50-state emissions-legal performance packages for V8 F-body cars, SLP maintains rigorous engineering standards. All systems are dyno-tested and designed to meet or exceed OEM fitment specifications, backed by SLP's lifetime warranty.

Performance You Can Measure

Documented power gains across applications include 12-25 horsepower increases, with torque improvements throughout the powerband. Reduced backpressure and optimized exhaust velocity deliver throttle response improvements and more aggressive exhaust notes at wide-open throttle.

Whether you're building a Firehawk tribute, maximizing your Coyote Mustang's potential, or unleashing your HEMI's full fury, SLP Performance exhaust systems deliver the perfect combination of power, sound, and street-legal reliability that's been trusted by enthusiasts for over three decades.