42DD MK4 1.8T K04 3" Downpipe

Over the years the Audi TT K04-020 turbocharger has proven to be a worthwhile upgrade on the K03 equipped mk4. Since the release of a few bolt-on K04 turbocharger kits the DIY crowd has been scouring the TT classifieds piecing together kits for less. Until now, no bolt-on downpipe has been available which allows the TT 225 K04-020 turbo and manifold to fit the mk4. Those days are over!

Our K04 3" downpipe begins at the turbo with a CNC machined turbo flange and the tightest 3" mandrel bend possible. The remainder of our downpipe is CNC mandrel bent in one piece to add strength and eliminate unnecessary welds. A stainless steel flex section is used to absorb engine movement. After the flex section a CNC machined flange allows a 3" high-flow cat or test pipe to be installed. We use a Magnaflow 200 cell metal catalytic converter in a spun stainless steel body. After the cat, custom adaptors allow perfect bolt-on fitment to any aftermarket cat-back. We offer adaptors for stock exhaust, 2.5" and 3" cat-backs. The whole downpipe bolts together with locking hardware and double layer graphite gaskets. Precision components and meticulous fabrication ensures zero leaks and zero problems.

The modular nature of our downpipe allows the user to change configurations at any time. For example, our downpipe may be purchased with a stock sized adaptor and connected to stock or any basic aftermarket cat-back exhaust. At any time a 2.5" or 3" cat-back can be installed using the appropriate adaptor. Our 3" cat-back systems are completely compatible with this downpipe allowing the possibility of a 3" turbo-back in any configuration. On race days the catalytic converter can be easily swapped for a test pipe.

Our K04 downpipe is available in 6 configurations. Street series downpipes include a Magnaflow high-flow cat. Race series downpipes include a test pipe. Each downpipe includes a cat-back adaptor available in stock size (2.15"), 2.5" and 3". Each downpipe is shipped complete with everything needed for installation. Additional accessories and hardware can be purchased separately at any time. All configurations can be purchased ceramic coated.

Besides price, the biggest worry on the minds of DIY builders is fitment. Our K04 downpipe was designed using precision tooling and the OEM Audi TT 225 turbocharger and exhaust manifold. Rigorous testing was done to repeat the phenomenal fitment of our mk4 1.8T 3" downpipes. Our downpipe fits like an OEM downpipe would and an aftermarket downpipe should - no rubs, no rattles, no problems.

Construction Highlights

  • CNC mandrel bent 14 gauge aluminized steel tubing
  • CNC machined 1018 cold roll steel flanges
  • Professional TIG welded construction throughout
  • 409 stainless steel 200 cell metal catalytic converter
  • Stainless steel braided flex section
  • Double layer graphite gaskets
  • Grade 5 locking hardware

Fitment Details

  • Fits 1999-2005 VW mk4 Golf, Jetta, GTI 1.8T
  • Fits 2000-2006 Audi TT 180 FWD
  • Fits VW New Beetle 1.8T
  • This downpipe will NOT fit any Passat or Audi A4
  • Available in street or race configuration
  • Choice of 3 adaptors allow unrestricted fitment to any cat-back

Available Options

  • Catalytic Converter
  • Adaptor Size
  • Ceramic Coating

Product Spotlight: Ceramic Coating

Starting at: $400.00

Please Choose:

Catback Adapter Size


Stainless Steel

Starting at: $400.00

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  • Model: EX-04-011
  • Manufactured by: 42 Draft Designs

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  • Hainesport, NJ 08036
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