For all diesel owners who must have visible exhaust tips.
I have fitted 4.4 V8 quad tip muffler/silencers (4.8is are $$ and like hens teeth) to my 3.0 diesel with only a little engineering/welding work on the pipes and flanges to keep the back pressure closer to standard. Find a good exhaust specialist you trust to carry out the work. You have to cut one of the standard dual pipes because it has no joint for some reason. By welding a smaller pipe (about 20cm) just inside both joint/flanges can cause a constriction of gases at low RPM resulting in enough back pressure to keep the turbo and the engine management computer happy. I needed to find a similar flange to match V8 ones so I could return the whole thing back to standard without cutting the V8 pipes. The 4.4 V8 quad tip silencers are freer flowing than the 3.0 diesel so you will loose take off torque if you just bolt them straight on without the restriction in the pipes. The engine management will adjust to the (restricted) flow over a couple of days. My X5 now doesn't look like it runs on batteries anymore and performs better at low take off and high speeds.
4.4 V8 silencers
Original diesel twin pipes
One clamped joint, other no joint
Non joint pipe cut close as possible to flange
Exhaust gas restriction choke welded inside flange
Mount cut and rewelded to widen pipes
to match V8 pipes.
Finished flange assembly with extention pipes
and matching V8 flanges.
V8 muffler/silencers bolt staight in.
