Fabspeed Over-Axle OPF Bypass Pipes (718 GT4)


Designed to Fit:

  • 2020+ Porsche Cayman GT4
  • 2020+ Porsche Cayman GTS / Boxster GTS / Boxster Spyder (4.0L Only)

Product Details

Ditch the factory gas particulate filters to increase power, save weight and add a throatier more aggressive tone. Our design process started with 3D scanning the entire exhaust system using our CREAFORM 700 Handscan so that we could make a complete Solidworks 3D model of the exhaust. We then designed the exhaust and fixtures using that model so that the exhaust fit perfectly to OEM standards. After multiple revisions for sound and dyno testing we settled on using a one piece mandrel bent over the axle exhaust pipe that goes straight into the free flowing part of the OEM PSE exhaust and a secondary pipe TIG welded to the main section to make a Y configuration to utilize the quiet side of the PSE exhaust when the valves are closed. Purchase these Fabspeed bypass pipes online.

SOUND: These Over Axle GPF Delete Pipes will bring out a stronger throatier tone from your 4.0l flat six. This is a mild but noticeable increase in overall volume over stock.

POWER: This part works best when combined with either one of our cat back options. With our Valvetronic X-Pipe it made tons of low end power, +14 whp and +32ft/lbs of tq at 2400 RPM, and maintained good gains all the way up to redline with +12 whp and 8ft/lbs of tq at 7500 RPM.


  • Mendral Bent 2.5" 63.5mm pipes for maximum flow
  • Over Axle pipes remove and delete the Gasoline Particulate Filters, GPF, found on all GTS, Spyder, and 4.0 liter GT4 cars worldwide 
  • Save 9 lbs / 3.5 KG versus the stock GPF over axle pipes
  • Significant Dyno gains across the RPM band when used with their Valvetronic exhaust +32ft/lbs TQ @ 2400RPM, +18ft/lbs TQ @ 3600RPM, and +15.5HP @ 7100RPM
  • Constructed from high-quality 14-16ga CNC mandrel-bent T304L stainless steel for maximum durability
  • More sports car sound and more exhaust flow
  • Designed, engineered and built 100% in house at Fabspeed using state of the art equipment and technology
  • Direct simple bolt-on installation, no cutting or welding required\
  • 25+ years of experience designing Porsche Exhausts
  • Backed by Fabspeed's Lifetime Warranty


            About Fabspeed

            For over 20 years, Fabspeed has been engineering and manufacturing the world's finest stainless steel high performance exhaust systems and components, air intake products, ECU tuning, and more, specifically-tailored for high-end sports cars and exotics. From Porsche to McLaren, our expertise is unmatched and it shows in everything that we do. Their dyno-proven performance products provide an exhilarating driving experience and are backed by a Limited Lifetime Warranty.

            Fabspeed strives to be a force of innovation within the industry; dedicated to maximum performance, excellent service, and true care and concern for the development of products and services for exotic car enthusiasts.