42 Draft Designs 2.5" & 3" Cat-back Exhaust Systems are designed specifically for VW Golf, GTI '99-'06' models. Attention to detail is what they do at 42DD, and that certainly shows in the design and construction of their 2.5" & 3" cat-back exhaust systems. From the hardware to the tip fitment it's clear upon installation that we've done our homework. Years of extensive development and long-term testing have gone into these systems. The end result is a cat-back system that fits great, sounds amazing, and adds hp & torque.
Designed to bolt to 42 Draft Designs 1.8T 3" downpipes, 42DD 2.5" & 3" cat-back systems begin with a CNC machined flange that connects to your existing downpipe. After this flange, an oxygen sensor bung allows for installation of the post-cat oxygen sensor. In a straight shot 42DD system bolts to your downpipe and slides into the first hanger, while a resonator removes rasp from the exhaust note. Next, 42 Draft Designs system makes the bend around the gas tank and over the rear axle. Fitment in this area is crucial. This over-axle pipe is bent correctly and built correctly to avoid rear axle rubbing on the lowest cars. Next, a Magnaflow muffer is tucked into the heat shields, almost hidden from view. To finish the system off there is three tip variations available for Jetta and GTI models - hidden, single, and dual. Our tips not only look amazing, but fit perfectly as well. These 42DD tips are made in-house from 304 stainless steel and polished to a mirror finish.
42 Draft Designs relentless attention to detail is proven by the fitment of their 2.5" & 3" cat-backs. 42 Draft Designs flanges are CNC machined in house from 1018 cold roll steel. Adjustable flanges are used where appropriate to allow each section to bolt-up as designed on every car. Hangers bars are precisely bent to slide into the factory hangers straight and level. At the rear hanger two collars were included and designed to lock the position of the rear muffler in place. Once you've adjusted your tip fitment - keep it there! Each and every system is built by hand on production tooling and TIG welded. All hardware needed for installation is included - gaskets, bolts, washers, and locknuts. Mechanical locknuts are used to assure your system never vibrates loose.
The sound of 42 Draft Designs systems has been imitated since the first sound clips hit the internet. The sound is described as "quiet when you need to be and loud when you want to be." At idle, the car emits a deep rumble. At low rpms and crusing speeds the sound is mellow and quiet. The exhaust opens up at full throttle and high rpms with a great tone and not a hint of rasp or drone. 42 Draft Designs tested various resonator and muffler conbinations before finding the perfect balance of power and sound.
While all of 42 DD long-term testing was done on 1.8T vehicles, this system will also fit turbocharged 2.0, VR6, and even TDI equipped mk4 VWs. Fitment is designed to connect to your existing 3" downpipe. The system will bolt-up perfectly to the 42DD 1.8T 3" downpipes, but 42DD also accomodates other brands of 3" downpipes and custom downpipes by including an extra flange. This flange is intended to be welded to the end of your existing 3" downpipe. Precise fitment of the 42 Draft Designs flange to your existing downpipe is necessary in order to fit this cat-back correctly. While this may seem like a hassle, it is necessary to assure a perfect fit. Keep in mind, these cat-backs are designed for factory and custom turbocharged vehicles (1.8T, 2.0T, VR6T). 3" piping is beyond overkill for all-motor applications and not recommended by 42DD. The 42 Draft Designs flanged system is designed to bolt-up to their 1.8T 3" downpipes and allow custom fitment to any 3" downpipe on any motor.
Horsepower and torque gains for these cat-back systems cannot be accurately reported as a nominal gain. These cat-backs can be installed on a wide range of vehicles - from a 200whp 1.8T to a 500whp VR6 turbo. Power gains always depend on turbo size, tuning, and what you're replacing.
42 Draft Designs 2.5" & 3" cat-back systems are available in 3 tip configurations and 2 styles to fit Jetta and GTI models. The 42DD single tip GTI system includes a 4" tip designed to fit the 337/20th valance. The 42DD single tip Jetta system includes a 4" tip designed to fit the GLI single tip valance. The 42DD dual tip GTI and Jetta systems include a pair of 3" tips spaced to fit perfectly within the stock valance. These systems fit all models from 2001+ with the factory dual-tip valance. 42 Draft Designs offer a hidden tip model for both GTI and Jetta models. Hidden tip systems dump exhaust gases before the start of the rear valance. Height and angle of the cut is designed to reduce drone and not melt the valance. The hidden tip is exposed only 1/2" below the bottom of the valance. Truely hidden.
Please Read BEFORE Purchasing
The 42 Draft Designs Mk4 2.5" & 3" cat-back systems are specifically designed:
Our Mk4 2.5" & 3" cat-back systems are NOT designed:
Fitment to 42 Draft Designs 1.8T 3" downpipes or as part of our 2.5" & 3" turbo-backs is as easy as described. Fitment to a 3" downpipe not built by 42DD requires welding of a 3" flange to the existing 3" downpipe at the correct location, angle, and rotation. Successful fitment of the 42DD 2.5" or 3" cat-back in custom applications is the responsibility of the owner. Fitment of the 42DD 2.5" or 3" cat-back to any stock downpipe or downpipe under 3" in diameter is not recommended by 42DD and cannot be supported.
If you need a bolt-on kit: check out the 42 Draft Designs slip fit cat-back! Mk4 2.5" Slip Fit Cat-back Exhaust
If you're interested in a full turbo-back exhaust, 42 Draft Designs offer systems for the mk4 1.8T which combine these cat-backs with the 42DD 3" downpipes to fit K03 and K04 turbos. Check them out! 1.8T 2.5" & 3" Turbo-back Systems.
Tip fitments are semi-permanent in the 42 Draft Designs exhaust systems. In order to change the tip later down the road you will need to swap out the rear muffler section. Contact us directly for pricing in the event of a tip change. Please try to ignore anyone who says "just take it to a muffler shop and have them weld on a new one." It's not that simple. The muffler and hanger is in the same location on all systems, but the tip itself and the pipe in-between differ greatly. Simply cutting one tip off and welding on a different one won't result in a system that meets 42DD quality standards.
42 Draft Designs tip fitments are very specific. Here are a few specific tip scenarios we would like to mention:
42 Draft Designs does not offer cat-backs in a non-resonated configuration. Long term testing proved that a non-resonated 3" system with the 42 Draft Designs rear muffler is not a worthwhile product. It doesn't sound great. It sounds raw and perhaps a bit 'import.' The 42 Draft Designs resonator does not affect the flow of the exhaust system in any way. It cleans up the sound of the 1.8T and plays a major part in the high quality sound of our exhaust. For this reason, a non-resonated configuration is not offered.
Motor Mounts Recommended
It is highly recommended to upgrade your dogbone motor mounts when using the 42 Draft Designs cat-back exhaust system. Worn out factory bushings cause excessive engine movement. Engine movement translates directly into the exhaust system - flex section or not. If your engine is slinging back and forth so is your exhaust. This means rattles, panic, and worry. The 42DD system is designed to be used with motor mounts. The fitment is exact - 3" piping is alot to stuff under a car designed for 2" piping.
Power gains cannot be definitively stated for this system. Every single installation is different. Power gains related to this system depend entirely on what's in front of it. 1.8T engines with complimenting mods and a 3" downpipe will see typical 3" turbo-back gains. A VR6 turbo with a 3" downpipe is going to see maximum power at whatever boost level their motor can support. A naturally aspirated 12v VR6 shouldn't be running this cat-back.
Last but not least, if you have any questions about the 42 Draft Designs 2.5" & 3" cat-back systems or any exhaust systems don't hesitate to contact us. We're available by phone, fax and email to answer any question you may have.