HIS4

I always though the term downpipe was reserved for turbo cars since it's the pipe that connects the exhaust side of the turbo to the exhaust/catalytic converter. Now I noticed a lot of the tuners have been making "downpipes" for newer N/A Audis. I always thought that the connection from the exhaust chamber on the block to the exhaust system was called headers. The only thing I can think of that would be a downpipe is if they made what was originally known as a header 2 pieces. The collectors from the block is one piece and then another pipe that connects the collectors to the exhaust that would be known as a downpipe. Is that basically what it is? Why not keep it one piece? Too hard to install that way?

Black01S4WI

BFD?

pink shrimp

I bought downpipes for my b6 s4 when I had it...

the term is probably just being used since its blurred in everyones mind

JW944

foundation first (excluding aspiration vs N/A): With OEM engineering of exhaust manifolds there are about 0 problem issues...no exhaust leaks at the exhaust manifold where it mates to the head/ no collector problems or cracking, etc...

"The collectors from the block is one piece and then another pipe that connects the collectors to the exhaust that would be known as a downpipe. Is that basically what it is?" - yes, basically

Used to be that headers were the option years ago (a one piece setup that mated to the head and ran down to the exhaust system) - and there were issues (at the least, you had to check them often and re-torque, etc). A lot has changed in the last 20+ years - but my casual observation is that there was an evolution to downpipes - OEM exhaust manifolds could/ would be retained and yet some performance obtained from adding a catback (IMHO catback is where the evolution really took off) and or a downpipe from the exh mani to the exhaust system tubing. So you retain reliability of the exhaust manifold and can easily add performance, especially for occasional track use. I believe emissions had a part in the evolution as well.

We don't want to get into sonic and pressure wave tuning/ scavenging...and it's a good idea when theorizing to differentiate race and street applications

ErikS4

that there is a turbo in the middle. A header is a single-piece combo that replaces both the downpipe and the exhaust manifold.