42 Draft Designs 3” downpipe is the single most effective bolt-on upgrade for the Mk4 Volkswagen 1.8T. No other basic physical modification can compete with the power gains delivered by this fundamental upgrade. Simply by reducing backpressure creates useable horsepower and torque throughout the power band while also improving turbo spool and throttle response.
Street Series downpipes are equipped with a 200/cell high-flow catalytic converter. Race Series downpipes include only a test pipe for track day. Included adaptor reduces pipe size to utilize the OEM band clamp. Additional cat-back adaptor sizes are available.
The modular nature of the 42 Draft Designs VW 1.8T KO4 3" downpipe allows the user to change configurations at any time. For example, the 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. The 42 Draft Designs 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.
Note: Vehicle MUST be equipped with OEM Audi TT 225 exhaust manifold and K04-020, K04-021, or K04-023 turbocharger. Fitment with aftermarket turbocharger or exhaust manifold is NOT supported.
Polyurethane transmission mount inserts are HIGHLY recommended for this application.
*Model years listed are based on US models. European model years may differ. If shopping for a vehicle sold outside the US please match chassis designation before matching model year.
This downpipe has been designed to fit a specific combination of vehicle, turbo and exhaust manifold. No guarantee or fitment if certain components are not used. The following components MUST be used to ensure proper fitment:
There are many aftermarket exhaust manifolds available which mimic the OEM TT 225 fitment. However, 42 Draft Designs has not tested any of these manifolds and there is no guarantee that the 42 Draft Designs 3" downpipe will fit properly. Additionally, many knock-off K04 turbochargers are available which claim to replicate the OEM turbocharger. No support or guarantee of fitment will be applied to the 42 Draft Designs downpipe if the proper OEM components are not used. This downpipe was designed to exactly replicate the fitment of the mk4 downpipe. It has not and will not be tested by 42 Draft Designs on mk2 or mk3 1.8T swap applications.
42 Draft Designs now offers v-band connection flanges with the stainless steel exhaust systems. Compared to 3-bolt flanges, exhaust systems built with v-band flanges are easier to install and adjust. V-band connections don't require a gasket, and can be serviced with a single tool. Overall, v-band flanges speed-up initial install and race-day component changes.
These V-band flanges are CNC machined from 304 stainless steel. Using a male/female fitment specification for the flanges aids in sealing the connection. Due to the material cost and manufacturing time, v-bands will remain a premium option.