Exhaust - Cat Pipe (JHM) 3" w/ High Flow Cat (HFC) for B7-A4 2.0T
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We ran a catless version of this Cat Pipe in our JHM 2.0T when we set the fastest stock turbo quarter mile record: 13.38 seconds at 100.3 mph! INFORMATION ON THE B7-A4 2.0T EXHAUST SYSTEM: After the turbo on the B7-A4 2.0T there are 3 different components in the exhaust system:
- TEST PIPE or CAT PIPE (OEM Cat Pipe): This pipe is the shortest section of the exhaust system and can be seen from the top of the car. It attaches to the turbo outlet and in stock form, contains the OEM Catalytic Converter. There are two oxygen sensors located on this pipe - one right after the turbo outlet and one after cat. After the cat, this pipe bends down to connect to the next part of the exhaust system, the CAT-BACK which includes the DOWNPIPE and the REAR EXHAUST.
- DOWNPIPE: This section of the exhaust attaches to the cat pipe and runs down from that connection over the CV shaft then under the passenger side of the transmission cross-member. In the stock formation, it connects to the REAR EXHAUST via a slip fit clamp where the end of the DOWNPIPE slips over the REAR EXHAUST.
- REAR EXHAUST: This final piece of the exhaust system is connected to the back of the DOWNPIPE and in the stock configuration splits into two pipes after exiting a resonator. After the resonator, the pipes continue to go apart and then lead into a muffler on each side. At the exit of the muffler, the REAR EXHAUST ends with the tips that you can see at the back of your car. Sometimes this section of the exhaust is mistakenly called the "cat-back". On the B7-A4 2.0T, a cat-back exhaust would replace BOTH the DOWNPIPE and the REAR EXHAUST sections. Most quality exhaust manufacturers sell true "cat-back" exhausts that will bolt up to your OEM cat-pipe or your test pipe. However, we have found that a number of manufacturers making exhaust products for the B7-A4 2.0T will market a rear exhaust system as a cat-back. Use this information to make sure you know what exhaust components you are replacing. THE JHM DIFFERENCE:
The JHM B7-A4 2.0T 3" Cat Pipe starts with nearly a 3 and a half inch opening at the turbo outlet! The outlet on the stock K03 turbo is 3.15 inches, so if we were to go with only a 3" inch opening on the pipe, we'd already be choking off the turbo! We opened up our pipe to the OEM Turbo to Cat Pipe gasket size which is actually slightly bigger than the OEM catalytic converter inlet. Click to enlarge picture
We also give our cat pipe the largest downpipe connection possible while still maintaining strength in the connecting flange. This pipe is NOT like other cat pipes out there which can neck down to the stock downpipe flange size. We make our outlet piping size as close to 3" as possible while still allowing it to hook up to whatever downpipe setup you currently have on your car. This leaves you room to grow into more powerful exhaust setups or just hook to your current stock downpipe. We maintain the stock bolt pattern but manufacture a custom flange that is opened up to receive our nearly 3" piping. Though this method **slightly** limits the size of pipe we can run at the outlet, we decided to put our piping inside the flange because it is a stronger way to build the flange connection while still allowing the test-pipe to bolt up to both stock and other downpipes on the market. NOTE: The picture below is of the JHM Test Pipe and is used illustrate the size of the Cat Pipe to Downpipe connection featured on our JHM Cat Pipe. Click to enlarge picture
The catalytic converter used in the JHM Cat Pipe is a high-quality, 300-cell, high-flow race cat. We locate it as far away from the turbo outlet as possible. While this made it a more difficult piece to fabricate and produce, we felt that it was the only way to do it since putting a restriction right against the back of the turbo would restrict airflow. Finally, our Cat Pipe features a J-bung for the secondary oxygen sensor. We have been working with several different configurations on this piece to get just the right setup for the B7-A4 2.0T. With our J-bung, not only will you be Check Engine Light free (for catalyst efficiency codes), but because of the way we've located it on the pipe, you'll also have easy access to the secondary oxygen sensor should you ever need to replace it! Click to enlarge picture
For those customers interested upgrading to our JHM 3" Cat Pipe who already have a larger downpipe (or are looking to buy our JHM Y-Adapter) we offer a no compromise gasket and hardware kit. When replacing your OEM cat pipe with our JHM Cat Pipe, you'll most likely need to replace the gasket at the cat-pipe to downpipe connection. Most companies just provide a stock gasket for this connection which has an inner diameter of ONLY 2.3". Not only is the JHM gasket that we include in our hardware kit made out of aluminum but it also features an inner diameter of 2.8" - the largest possible diameter while still maintaining the stock bolt pattern. To purchase this hardware kit, please go back one section and add the item to your cart. You can also search for "JHM 2.0T Hardware Kit" in the search box on the top, right-hand corner on any page on our website. Click to enlarge picture
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Off-road use ONLY: THIS PRODUCT IS FOR RACING COMPETITION ONLY AND IS NOT LEGAL FOR USE IN HIGHWAY OR STREET VEHICLES OR OTHER NON-RACING COMPETITION OFF-ROAD VEHICLES. BY PURCHASING THIS PRODUCT YOU ACKNOWLEDGE ITS INTENDED USE.
|Audi||A4||B7 (2005.5-2009)||2.0t FSI|
- Excellent fit and finish! Great looking HFC, beautiful welds! Installed perfectly, no CEL, hardware kit was an excellent addition. I feel my car has been juiced up with a little extra power, especially in the higher RPM range of 3-5k RPM. Its definitely been "woken up". Turbo lag is basically gone. Yet this is a very stealthy addition, my wife didnt even hear a difference. So to you guys out there that have an exhaust noise limitation imposed by your "better half", this is the pipe for you! Great deeper undertones under WOT, and a very subdued tone during normal driving. (Posted on 1/30/2017)
- I get tons of compliments on the sound of my exhaust people can't believe it's still factory stock with only a test pipe. Love the sound, performance and finish look after installation. The installation kit is great and makes install much nicer. I rant and rave about this test pipe all the time. (Posted on 10/24/2015)
I just have to say, it's worth every penny! You can actually hear the Turbo spool when you rev it idle or a stop, and it just is a lot more aggressive and gives you a bit of that good old gas smell without being overwhelming. With that and a Revo Tune, while on stock tires without any other mods besides mounts, got a 0-60 of 5.5, compared to 7.2 from C&D.
You definitely owe it to yourself to get this ASAP (Posted on 7/11/2014)
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