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JHM Downpipes - B6 A4 / C5 A6 (3.0L)

Catback Connection

As many of our customers know, we have been working towards the release of the JHM B6-A4 3.0L V6 Downpipes for a long time. After lots of prototyping, testing, trips to the track, and re-prototyping, and re-testing, we are proud to announce that our B6-A4 3.0L V6 2.5 inch Downpipes are ready to sell!


Why 2.5 inch piping diameter?


We tested a few different piping sizes (2.25, 2.5, and 2.75) and found that in every configuration - stock ECU calibration with a stock sized (54mm) cat-back, stock ECU calibration with an aftermarket cat-back, JHM Tuned ECU with a stock sized cat-back, and JHM Tuned ECU with a stock cat-back - that 2.5 inch piping diameter provided the best gains in acceleration and high-end power without sacrificing low-end torque.


If you are looking to unlock the potential of your 3.0L V6, these 2.5" downpipes are the key. They are an absolute MUST for anyone looking to get more power out of their car. Our extensive research proved this point time and time again. When we put our 2.5" downpipes on a stock car, the car was impressive and the increased airflow of the downpipes definitely made the car seem a bit more "peppy". However, when we put the downpipes on a car with a JHM B6-A4 3.0L V6 ECU Tune on it, the result was amazing. The combination of the increased airflow from the downpipes and the ability of the JHM ECU Tuning to take advantage of that increased airflow completely transformed the power band of the car. The gains in low-end torque were good but the most impressive power increase can be found in the top-end of the RPM range. With the motor breathing more freely and the addition of our ECU Tuning, the 3.0L just keeps accelerating up top!


The biggest gain in power comes from removing the huge catalytic converter complex that Audi has placed right up against the head of the motor, just after the outlet of the exhaust manifold.


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Audi Exhaust - Downpipes B6-A4 3.0L Stainless Steel, 2.5 inches


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Audi Exhaust - Downpipes B6-A4 3.0L Stainless Steel, 2.5 inches


Look at the size and location of that cat! This drastically slows down the airflow coming out of the motor and creates heat - both of which are bad for making power. By removing the catalytic converter AND increasing the piping diameter to 2.5", we solve both of those issues! Actually, the inner diameter of the JHM Downpipe at the inlet is over 2.5 inches!


Click to enlarge picture
Audi Exhaust - Downpipes B6-A4 3.0L Stainless Steel, 2.5 inches


Click to enlarge picture
Audi Exhaust - Downpipes B6-A4 3.0L Stainless Steel, 2.5 inches


These are the same style downpipes that were featured on our record setting, "JHM3LTR", our in-house B6-A4 3.0L V6. See them in action in the video below. It also provides some great sound clips of different exhaust configurations!



Our JHM B6-A4 3.0L downpipes have a reducer at the end of the pipes that will allow you to run these pipes with a few different cat-back setups:
- Stock B6-A4 3.0L V6
- Stock B6-S4 Cat-Back
- ANY Brand X B6-S4 Cat-Back designed to mate up to stock downpipes
- Full 2.5" for JHM-FI B6-S4 Cat-back


In our testing of different exhaust setups and in our experience with cat-backs for the B6-S4, all aftermarket cat-backs neck down to the stock piping size EXCEPT for the JHM/Fast Intentions 2.5 inch cat-back. So, if you have a stock cat-back or pretty much any other aftermarket cat-back our JHM 2.5" downpipes will bolt right up to your system! Just secure your downpipe to cat-back connection with your OEM downpipe to cat-back clamps. If you need OEM downpipe to cat-back clamps, we sell them in our store. Just search for "clamp 54mm".


**Note: If you are interested in running a full, 2.5 inch exhaust setup, we already have adapters made to connect our B6-A4 3.0L V6 2.5 inch downpipes to most FULL 2.5 inch B6-S4 Cat-Backs (i.e. ones that don't neck down to stock pipe sizing), including our JHM-Fast Intentions Cat-Back. Call us for details.**


- 1x Pair of JHM 2.5 inch Downpipes


NOTE: We recommend replacing your exhaust manifold to downpipe gaskets every time you remove your downpipes from the exhaust manifolds. You can purchase these in the same section as you found this product in or by searching for "3.0 exhaust manifold gasket".


- ALL quattro B6-A4s - 2002 to 2005 - with the 3.0L V6 (Manual or Automatic Transmission)

Tags: 1998 , 1999 , 2000 , 2001 , 2002 , 2003 , 2004 , 2005 , A4 , A6 , Audi