Downpipe
The build is moving on despite the lack of posts on here. I really believe I'm in the final stage of sourcing parts for the build...
One of those parts is the downpipe that I at last ordered this week after carefully investigating what the options are.
The kitt comes with a CAT and piping to connect the OEM exhaust fitted on a TTRS/RS3, I'll produce a custom mid-pipe in between to instead connect to my aftermarket 3" CAT back.
My selection was not done due to a specific brand, it was all based on functionality. This APR 2.5T downpipe is casted and has a smooth and large reducing initial neck to allow the exhaust gases to expand and cool down.
This is really the only off the shelf downpipe on the market that according to me makes the transit in between the turbo exhaust side and the downpipe in a proper way, smooth downsize from 4.68" too 3".
Other downpipe options utilize a direct downsizing 3.5" connecting exhaust flange, this prevents the exhaust gases to exit in a optimal manner.
In the image below you can see one example of the (non casted) welded 2.5T downpipe option from the same supplier, have a look on the initial neck to see the direct obstacle the flange creates.
