in the fall I took my old - swiss cheese exhaust off of my 82 300sd and welded up about 14 feet of 2 1/2" stainless steel pipe - I modified the path slightly for a little more straight run, but just because it was easier (I had to relief cut the inside of the curve and weld it back together - I couldn't find anyone local to bend it for me). I have been running it for about 6 months now and I am happy with the results - #1 total cost was $140, #2 the exhaust isn't any louder than it was with the swiss cheese pipe, #3 I shouldn't ever have to replace it (I used hand railing pipe - quite a bit heavier than most use) and #4 people always know I drive a diesel!
I don't notice any performance changes, or mpg increase, but all in all worth it I would say

in a gas engine less back pressure is always good but it may cause need to adjust fuel delivery.

i remember back in the carburator days if you put on a very low pressure system you often had to rejet. i think richer.

then you got a bit more power.

and i have read that the webers on an old ferrari cannot be adjusted correctly if there are any leaks in the exhaust system.

tom w

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

One word for gassers: EFI. Problem solved.

My muffler system from the resonators onward is pretty rusty...don't know how long it has left, I've stopped trying to prevent its demise as the rust spray/paint is a waste of $$ at this point....chunks have been falling out of it and it won't be long till there's holes on the pipes going in and out of the resonators, there's already a small one on one of the short downpipes in back.....at the very least I am going to dump the resonators....Muffler....depends...I'd probably go with a 3" straight pipe right to the back, maybe split at the end with a nice double end piece or something.

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-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

You can take about 25% off the build cost to use 2.5 over 3. 3" is a waste and 2 1/2" from turbo to tail is more than our engines need. We don't have a 400HP cummins under the hood, 180Hp is all we can hope for without upgrading the pump internals.

It's like a 5" pipe on a Dodge/Ford/GM or 7" stacks on a semi. They look really cool but in the end are just for show.

I've been running without an exhaust for a month now I think.. was just messing around and unbolted the section under the drivers seat. It's pretty fun around town, kinda gurgly like a V8 with a lot of turbo whine. Once I get on the highway, from 60-70 mph the resonation is pretty bad. Not really a problem since I cruise at 55 and always have music playing.

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1985 CA 300D Turbo , 213K mi