1.8L VS 2.0L T4 exhaust systems Options

[technicalninja]

I've wondered why Porsche built different exhaust systems for the T4.

It appears that any year complete exhaust system can be installed on any year T4.

And yet the systems are so different that even the mount at the transmission needs to match the exhaust.

Why?

It seems the systems have the same size pipes.

The 1.8/1.7 have a short "S" kick up at the back that doesn't look like it will affect flow very much.

What am I missing?

Are the 2.0L mufflers higher flow?

Was it just a sound difference?

I didn't "see" an obvious flow difference when I bought a pair of used 1.8L SSI exchangers and the Bursh muffler that fit them.

Was I wrong?

[Superhawk996]

The differences between OEM versions are sort of moot.

If you are running near stock, the differences are negligible though even that minor s bend surely adds some incremental head pressure vs a straight pipe.

If you’re running a performance build you would be running headers and a free flow exhaust.