thickening in the front exhaust pipe

[Peter]

Does anyone know what the function is of the thickening in the front exhaust pipe?

Has it also a silencing function?

Thanks for help, Peter

[Pawel66]

It is quite important, actually, for the sounds and optimum performance. There are venturi connections between the pipes that manage the flow and pressures of the exhaust fumes from particular cylinders. The way they are done and the distances are important there.

Many posts on this on the Forum, e.g.: https://www.sl113.org/forums/index.php?topic=27708.msg200054#msg200054

[MikeSimon]

"Crossovers" in exhaust pipes are indeed important. They manage and influence torque characteristics at certain rpm ranges. The engineers did not do this because they didn't have anything else to do.