jrobgood71

So this is an odd question, but it's going to be a pretty binary one, meaning you're either going to know the answer completely, or not at all.

On MB dual pipe exhaust systems (and some BMWs apparently) where the midpipes transition from the secondaries into the tandem resonator, one pipe has a ball flange that mates with the flared pipe on the resonator. This joint is held together and sealed with a v-band clamp and no gasket.

Its sibling from the other cylinder bank is straight cut (no flare nor taper) and mates with its flared pipe on the resonator using a compression gasket and a v-band clamp.

The flared inlet pipes on the resonator are the same diameter, with the same flare size. From what I've seen, their lengths are different, usually by 2 or 3 inches.

So... why are there two different styles utilized in this joint? The only thing I can think of is that it might allow the pair of parallel tubes to torque or yaw laterally without binding, by letting one of the two slip in and out a few millimeters if needed.

I'm attaching pix. In the last image, you will see that the pipe at the bottom of the image uses a straight cut coming from the cats and a compression gasket, while the one above it is metal-to-metal ball and flare. If you know the answer then you know what's underneath them.








NOTE: Ignore the ghetto muffler clamp and the bit of metal extending from the bottom straight pipe into the flare... that's my temporary slip fit setup while I dial this rig in.