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Discussion Starter · #1 ·
I consider myself pretty knowledgable when it comes to cars, but I don't know EVERYTHING, so here's my question: What exactly is an uppipe? I know a downpipe comes out of the exhaust manifold which goes to the midpipe, which connects to the cat. And by all means, if I'm mistaken, please correct me. :)
 

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you have it a tad bit mixed up... the uppipe is a pipe that connects from the right side exhaust manifold to the turbo... the downpipe comes off the other side of the turbo and leads to the midpipe, to the axel back.
there are 3 cats in our WRXs. 1 in uppipe, 1 in dp and 1 in midpipe. most aftermarket downpipes replace both the stock dp and the midpipe, making it one whole pipe.
hope this helps... search some too and you may find some better answers then what i have. ;)
 

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Discussion Starter · #3 ·
Ahhh... it's a little more clear to me now. I actually don't have a WRX yet. I still have my Civic, but I'm selling it when it gets back from the body shop. Otherwise I would have popped the hood and looked for myself haha. Anyway, you helped out a lot. Thanks for the info! :)
 

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campbell said:
I have the full version of this pic if anyone needs it. Not missing much though.
Yeah, post it up. I only have the small version and was looking for the large one for this thread.
 

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It has to be cropped to fit. It is like 1200 pixels wide and this site only allows you to post 1030 or less. So it had to be cropped. If you would like me to email to you I can. Just post your addy here.
 

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Here is a good side picture of our engine on a stand. This shot show the uppipe between the turbo and the exhaust manifold. Note: The manifold (header) uppipe and turbo are all aftermarket upgrades.

 

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Discussion Starter · #10 ·
Wow that diagram and picture really helped me out a lot. But I'm still somewhat confused... So the downpipe comes off one end of the turbo, connects to the midpipe, and leads out to the back end of the exhaust. The uppipe comes off the other end of the turbo, connects to the exhaust manifold... now where does the manifold lead to?
 

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Here is another diagram I did. Maybe this will help a little better. Note: I am not showing the cats in this system.
 

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Yeah, it can be a little confusing sometimes.

The WRX is the only car I know of (sure there is more) that has a CAT before the turbo (ie between the cylinderhead and turbo). Most other turbo cars have the cats after the turbo. I can only assume that the pre-turbo cat was some method to reduce cold engine emmisions.

Then there are cats in the downpipe (normal for other cars) and another one in the mid-pipe.

Anyone know if regular sedans have multiple cats or just a single one right after the cylinderhead?
 

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nice diagrams Matt........did you produce them for a report/ analysis/project of some sort, or just FYI ? Very Nice anyway...
 

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WtuRboX said:
So the downpipe comes off one end of the turbo, connects to the midpipe, and leads out to the back end of the exhaust. The uppipe comes off the other end of the turbo, connects to the exhaust manifold... now where does the manifold lead to?
Nick the exhaust manifold comes straight from the engine. This is where the exhaust gases start and head thru one cat, into the turbo, out the turbo through another cat, thru yet another cat in the mid pipe, and finally through the resonator and muffler.
 

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nice diagrams Matt........did you produce them for a report/ analysis/project of some sort, or just FYI ? Very Nice anyway...
Just FYI. I had to do it for myself so I could understand the exhaust system. It's very complex and confusing to a beginner. A picture is worth 1,000,000,000 words in my book.
 

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Took the base picture from howstuffworks.com am i correct? Nice additions to it by the way.


picture is from Garrett.
 

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