I ' understand ' the pulse waves of an equal length header system...and that it is usually oriented to a very specific rpm... for racing... and often has negative effects at other rpms not suitable for all around road vehicles...
Do you feel less alone now ?

No boost spikes in a stock 617 without an exhaust. Also, your argument about exhaust pulses do not apply to turbocharged vehicles (taking some basic assumptions into account) post turbo. Turbo exhaust tuning all takes places pre turbo and in the size of the turbo chosen. Post turbo the pulses are superfluous. Your links and articles do not hold a candle to the issue being discussed here.

Taking off a fucntioning muffler will not noticeably improve or impede the performance of a 617 powered diesel. It is possible that it could be collapsed and plugged inside but if you have ever but open a 617 muffler you could easily see why your chances of winning the lottery are better.

Because I have to keep reminding myself that this is a ' recurring pattern of behavior ' on your part.... that you will take an illogical stance on a subject if I am the one who said something different.
Any CO leak is dangerous. No matter how small because being exposed to CO robs the body of the ability to attach OXYGEN to the red blood cells...
There are instances of people on long trips where they wound up in the hospital due to TINY but days long exposure to CO . I saw a family interviewed on GMA years ago which this happened to... they were probably not driving a diesel but I do not remember and that is not the point... but that any CO exposure is dangerous and that diesels are capable of making CO...
Why would your criteria for ' not healthy ' only involve DEATHS... and the idea that just because you personally are not aware of something so obvious to everyone else as being a safety concern is hard to understand... unless the first point I made is taken into consideration... that you are wanting to a dispute with ME... not that the facts of the situation rule your thinking .

I believe I would have better luck arguing with the bag of hammers I have in front of me. The articles in links provided go into great detail about boost spikes and how your standard gauge is incapable of detecting it. Doesn't matter as the magical 617 is impervious to the laws of physics. It can shrug off pulse waves in a single bound, able to put out more power with or without an exhaust. Can magically have complete combustion without CO. Is there a Kryptonite equivalent for the 617 or is it like Chuck Norris, He can break one side of a window.
http://www.chucknorrisfacts.com/

If I like to disagree with you then I will be posting ALL days. I am only posting because diesel car is DIFFERENT from gas car as far as CO poisoning is concerned. This is an UNDISPUTED fact. I am just telling you the scientific facts.

If you want to defend a hole in the muffler will cause CO to creep into the car and cause poisoning or DEATH then it is your prerogative.

I have nothing to add and you can take the floor.

Answer
 

Lower power suspects:
* Plugged muffler (due to corrosion failure).
* Plugged fuel filters.


I agree the timing could easily be coincidence.




.

Health Safety
 

I agree that a persistent CO leak in an un-vented enclosed space is dangerous due to cumulative exposure.

As a note:
Don't bother trying to commit suicide by CO poisoning with a diesel = in a sealed two car garage after twenty four hours of trying you will get a massive headache and vomiting for up to three days..




.

We have all sorts of folks come from many places and when they talk about forced induction on gasoline engines and try to relate that experience with a diesel engine it invariably ends up like this. The gas guys thinks he knows it all about turbo charging and sometimes even supercharging. He knows about "mega-squirt" and other tricks on a gasoline engine. He knows what adding more fuel with high boost does in a gasoline engine. Very little of the information applies to diesels, much less smaller high rev diesels. The gas guy eventually does some study on his "new" diesel and learns that much from the gas forced induction world simply does not apply to the compression ignition engine, and he either comes around, or leaves the forum.

a little off topic but I have recently removed my hollowed trap cat and had a hand made y pipe made for it, the result is that there is no power change but the exhaust note is a little strange, before the pipe it used to buzz at 2000 rpm like bees in a tin can after it, its a hollow muffled buzz (burble) at 2000 - 2500 rpm at the exhaust tip. (btw I had to get the back box retipped as the PO thought a 2 3/4 inch pipe that fits sideways was cool)

any ideas..

Ahh, well after all that discussion and debate, I found the reason for the power loss. I wasn't pressing the gas pedal when I wanted to accelerate, I was pressing the brake. No wonder theres a power loss....

Kidding. But actually I did an oil and filter change today and Im actually shocked at the difference it made in the power. Ive been trying to keep oil changes regular but perhaps it needs to be even more regular. Ive never felt such a difference with an oil change. I always thought it was simply something that you had to do but you dont necessarily notice the difference in short term performance.

Ill gte to the muffler sooner or later. Ive patched two large holes with the quick patch fiberglassy tape stuff. I thought it was just that one had come off, but this one is a hole I cant see on the top of the muffler just before the box.
Its obviously falling apart. Ive got plenty of flexible muffler repair tubing lying around the shop but I wonder if its worth it to keep sinking time and energy into the ol dino.

It looks like the bolts that connect the front section to the rear are pieces of rust now, not looking forward to having to deal with it in the next month.

I wondered if there were better materials for mufflers that would last longer. I have a decent amount of welding scrap around like aluminium and stainless. it seems mufflers are one of the first things to corrode away on almost any car.

At one time you could buy all aluminum mufflers....

Yep, I am an idiot. Apparently 4 stroke diesels are completely different than 4 stroke Gas engines. My diesel marine background doesn't matter either. I wish I had known all I had to do was drill a few holes in my muffler. Maybe I should email Banks and let them know they wasted money working on developing new exhaust systems for diesels. From the very beginning I agreed that it was most likely coincidence but that the wording of the question required at least some real information. The fact that someone suggested that rust holes would increase power was too much for me to take.

I am sorry that all your training has gone for naught...according to you..... are you watching your blood pressure ? That is important ..... don't let them get to you...

BIG PICTURE:

1) WIDE OPEN EXHAUSTS
The less restriction on the exhaust in any 4 stroke engine, the higher the potential you have for MAX HP at WOT......assuming your intake and fuel can support. Turbo, N/A.....doesnt matter. Go look at ANY drag racing car/motorcycle/etc and observe their exhaust systems. SHORT AND HUUUUGE!!!! I used to get a kick out of seeing turbo 4 cyl running a 6 inch pipe out the side of the car behind the front wheel!


2) TUNED EXHAUST
A wide open exhaust gives max HP at WOT, usually leaves something to be desired down low. A specially tuned exhaust can boost lower end torque, but will rob a few HP off the top end. It can modify and move your torque curve throughout your engine's rpm. It will never give you all the HP that a wide open exhaust does, but it will make your power band broader and more useable anytime you are not at the dragstrip. This applies to N/A and Turbo engines. Turbo engines are less affected due to the damping affect of the turbo itself. Why do track race teams carry so many different exhausts? Every different exhaust is tuned to move and modify their torque curve. If the course has a lot of hairpins and technical/slower speed turns, they will need a pipe that provide them with the best low/mid rpm torque for accelerating through RPMs. If it is a wide open track, they will use a pipe that gives them max tq near their max hp for high RPM WOT runs down the straights. get it?

NOTE: Did Mercedes have an optimally tuned exhaust for their early 80s Turbo Diesel sedans? Probably not..... I personally ditched my perfectly good 300SD OEM exhaust and straight piped it.....because I love the sound of the turbo diesel...... and it made 0, thats right, 0 noticeable effect on performance...good or bad...

This is an awesome thread.

Reminds me of an epic battle at a retirement home.