Hey,

Well I had my exhaust break in two spots a month ago so I patched it up with wire hangers and those crappy patch up kits they sell. The car was extremely loud and seemed slower. Today my father and I installed a brand new OEM exhaust which we bought for 200 bucks. We lined up the two together and they were identical except the manufacturer was different.

Once we installed the whole thing the car ran so much smoother and quieter. It even seemed faster.......

Can this actually happen ? Or was it all in my head since I did not hear that awful diesel sound ?

Thanks


ps.... the car is a 83 240D

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Audi TT

In theory, an exhaust system with less restriction should provide more power.

That's an insult to us Diesel nuts.

i like the diesel MOTOR sound but when the exhaust has a few big leaks in it then it sounds like a giant tractor about to fall apart

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Audi TT

Try running the Diesel ENGINE straight pipe for 8 months. I know you will like it as much as I did.

It MAY add more power, I don't know if you'd notive though. It's probably all in your head, for instance, my car runs a lot better right after being washed up. NOw, I know it isn't faster, but it's all in my head. Who knows, my SD is not the most aero-dynamic, so it probably IS faster after a bath and wax.
Thanks
David

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2000 Honda Accord V6 137k miles

1972 300SEL 4.5 98k miles

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I don't know if this holds true with M-B diesel engines but some engines need exhaust back-pressure in order to develop their torque. I recall hearing that some engines were also exhaust tuned to run smoother. I had a Mazda rotary engined car back in the early 80's and when it developed a leak in one of the mufflers, it ran terrible. After I rewelded the seam that had broken, it ran smooth as silk.

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DJ


84 300D Turbodiesel 190K with 4 speed manual sold in 03/2012

I am running my 300SD straight piped. and it may not be as bad as a 240D since it has a turbo on it.

It doesn't run any faster. louder certainly, and maybe a little less lag. too bad i need to get it fixed for safety inspections

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198? 300D ???K - Future DD
1989 300TE 285K - traded in '12
1984 300SD 186K - Sold in 08
1978 300SD 330K - Died in 05

Turbocharged engines like as little restriction as possible after the turbo. You may notice a little more lag before the turbo spools up, but you will ultimately have more power when the turbo is producing boost (>2400 engine rpms).

I had a straight pipe on the Beetle for over a year... it wasn't too obnoxious... nothing at all like a Civic with a fart-can.

No, it will definitely NOT add more power unless the old system was SERIOUSLY restricted.

If it were a modern gas engine it would indeed, but on a normally aspirated diesel NO. The power of your diesel is determined by ONE THING, and that is the amount of FUEL that reaches the cylinders.

Gas engines and diesels are DRASTICALLY different in this way.

Have a great day,

Aaah, just noticed that it was a 240D.

That's a g@$ engine thing. While straight-piping a diesel may not help too horribly much with power on its own, it will lower your exhaust gas temperature, meaning that the engine isn't working quite as hard. This may make the engine last slightly longer, or it could allow you to increase the fuel output slightly (but DO NOT do so without an EGT gauge!)

The real limiting factors with diesels is legality and your own comfort level. Especially with an M-B exhaust, I don't think you'll get that much of a benefit (the pipe is already way oversized for these cars; the pipe on my 300D is bigger than the pipe on my F-250!). But, on a turbo engine, I'll bet it sounds

Your engine would be perfectly happy if the pipe was cut off right at the outlet from the turbo...but then you'd have a heckuva mess ot clean up from the soot in your engine compartment and under your car

All engines have to breathe. The MB exaust system seems pretty adequate on the 240D. Restricting it however could cause significant loss of power. I have seen some pretty aufull things welded under cars. A common swap used to be to use a cheap Ford Falcon muffler in place of the round Mercedes muffler. They are both round. The Falcon muffler has much smaller passages inside. When you use the cheapest stuff you can find, the passages get even smaller.

If you removed some trash that did not belong there in the first place, and replaced it with the right stuff, or as suggested earlier, gotten rid of something clogged, you very well might have regained lost power.

However it sounds like the loss of power occured when you patched up the exaust system with the bailing wire and goo. Perhaps you managed to get something cocked or got enough goo into the muffler to restrict the exaust.

I used to get significant increase in power by increasing the size of exaust pipes and replacing OE mufflers with low restiction mufflers, or converting to dual exaust, but when the original exaust system was adequate, the increase was not worth the cost.

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69 220D not running
79 240D parts car
80 240D Beater runs everyday
81 300TD temp disabled cooling problem
82 300SD sweet