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The bellmouth transitions to 304 stainless steel 3″ piping which leads to the Cobb catalytic converter. Cobb departs from your typical ceramic cat. by using a spun metal substrate unit offering greater flow capability as well as product life. In addition this material also reaches operating temp. faster helping to reduce those nasty pollutants the CHP is trying to bust you on. The Cobb downpipe ends with a reducer transition that uses the factory exhaust gasket and mounting hardware. I have had more than one person tell me that performance is reduced because the exhaust “necks down” at this junction. The reality is that this is a very intelligent design and people pay attention to forum experts too much. Specifically this reduction not only allows you to use the factory exhaust gasket and hardware, it also eliminates the often experienced boost creep seen with other catless and straight through designs. The downpipe also incorporates a mounting bracket to attach to the factory downpipe brace and an O2 sensor provision after the cat.
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| From the spun substrate cat to the perfectly placed support brace, the COBB downpipe FIT perfectly and is built to last! |
Despite my pledge to remain old and lame with the stock exhaust, Cobb announced the release of a new catback system for the GR chassis STi. I could hear the horrible racket in my head already and the thought of highway drone made me want to swallow a bunch of pills. Alas I agreed to watch a VIDEO that Cobb had produced to showcase just how good their exhaust sounded and after review I had a thought, If I wasn't happy with the sound I could just weld in a BIGASS resonator right? Well time would tell if that was necessary but I decided to try and up my cool points with the Cobb cat-back at the same time as the downpipe.
When the exhaust boxes arrived I quickly hustled them in to the garage and began unpacking. Hell, I had 10 minutes to kill before I had to be at a meeting… Well I barely got the muffler section out of its wrapping before I had to go. The packaging gets just as much attention as the metal work of art contained within. I had to save the other two for when I returned and they were packed the same way. I think I spent a good 25 minutes opening and carefully unwrapping all the parts. Having bought tens of thousands of dollars worth of parts over the years I tend to be a judgemental prick when it comes to packaging, and honestly I don't think I have seen better. Even the boxes are nice and white and are all labeled in a uniform fashion with Cobb tape.
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| Even the packaging is high quality. If this thing gets damaged during shipping chances are your carrier is Ace Ventura… COBB also includes the necessary bolts and even some swag. Also notice the use of a perforated core resonator. I was happy to see this feature! |
As you would expect fit and finish are first rate. We had no trouble fitting the downpipe and the install was quite easy. When I say we I really mean I as I installed the downpipe in my garage using only jack stands and basic hand tools in just a few hours. The only modification required is to trim the OEM turbo heat shield as the lower portion will not clear the bellmouth design. While some people will remove the shield all together, we chose to trim as little as necessary in an attempt to keep as much heat IN the downpipe as possible. Considering the intercooler is just a few inches away this is hugely important.
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| Here is the downpipe nestled all snug in its bed. The bracket in the picture is the OEM piece re-used to attach the factory heatshield after it is trimmed to fit over the new downpipe. We installed that immediately after we took this picture. |
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| Here is the view from underneath the car. Here you can see just how much room there is making for a nice easy install. You can also notice the factory heatshield that has been trimmed to fit. |
