Our Mk4 2.5" & 3" cat-back systems are specifically designed:
- to bolt-up to our 1.8T 3" downpipes (K03 & K04)
- as the rear portion of our 1.8T 3" turbo-backs
- to be custom fit to a 3" 1.8T, custom TDI, 2.0, or VR6 3" downpipe
- to be used on heavily modified vehicles
Our Mk4 2.5" & 3" cat-back systems are NOT designed:
- to connect to a stock 1.8T downpipe
- to connect to a stock 12v or 24v VR6 downpipe
- to fit any vehicle other than a mk4 FWD chassis
- to provide astronomical gains on a stock motor
Fitment to our 1.8T 3" downpipes or as part of our 2.5" & 3" turbo-backs is as easy as we describe. Fitment to a 3" downpipe not built by 42 requires welding of a 3" flange to the existing 3" downpipe at the correct location, angle, and rotation. Successful fitment of our 2.5" or 3" cat-back in custom applications is the responsibility of the owner. Fitment of our 2.5" or
3" cat-back to any stock downpipe or downpipe under 3" in diameter is not recommended by 42 and cannot be supported. There are reasons why we make specific recommendations.
If you need a bolt-on fit: check out our slip fit cat-back! Mk4 2.5" Slip Fit Cat-back Exhaust
If you're interested in a full turbo-back exhaust, we offer systems for the mk4 1.8T which combine these cat-backs with our 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 our exhaust systems. In order to change the tip later down the road you will need to swap out the rear muffler section. Please 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 our quality standards. Contact us.
Our tip fitments are very specific. Here are a few specific tip scenarios we would like to mention:
- Our dual tips will not fit under a non-cutout valance
- Our single tips will not fit under a dual tip cutout valance
- Our hidden tip is hidden, unless installed behind a cutout valance
- GTI systems will not fit Jettas
- Jetta systems will not fit GTIs
We do not offer our cat-backs in a non-resonated configuration. Again, there's a specific reason. Long term testing proved to us that a non-resonated 3" system with our rear muffler is not a product we would like to put our name on. It doesn't sound great. It sounds raw and perhaps a bit 'import.' Our 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, we do not offer a non-resonated configuration.
Motor Mounts Recommended
We highly recommend upgrading your dogbone motor mounts when using our 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. Our 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 our 2.5" & 3" cat-back systems or any of our exhaust systems don't hesitate to contact us. We're available by phone, fax and email to answer any question you may have.