Does Muffler affect power? - PeachParts Mercedes-Benz Forum

azitizz · #1 06-21-2011, 11:23 PM

I was just wondering if holes in a muffler would affect the power in a 85 300TD wagon.

#1. Recently my car seems to have been less powerful and I found out there is a 3rd hole in the muffler after patching

#2. The loudness of the 3rd hole discovered seems to be coincidentally timed with the power loss.

Could there be any relation?

I didn't think so, but hey, I'm still learning about these machines..

Thanks

1980sd · #2 06-21-2011, 11:27 PM

All your power could be running out that hole...

azitizz · #3 06-21-2011, 11:31 PM

Quote:

Originally Posted by 1980sd

All your power could be running out that hole...

Serious?

I found the hole just near the joint to the front of the silencer, on top I believe.

leathermang · #4 06-22-2011, 12:05 AM

LOL,,,,, no,,,,he is kidding...
only in a situation where you had tuned exhausts would a hole mean less power... otherwise it would mean more power due to less restrictions... but increases the chance of CO getting into the car... so they need to be fixed for many reasons..

woodboat3 · #5 06-22-2011, 12:11 AM

When I added straight through mufflers on my turbo 5.0 mustang it lost considerable power. Lower back pressure meant lower power. I had to make adjustments to the fuel curve and wastegate to get power back. Ultimately I had more power but it took some serious adjusting so with a turbo I would say it is possible at the very least to lose power from an exhaust leak.

leathermang · #6 06-22-2011, 12:19 AM

I would think that a late model turbo 5.0 Mustang would pretty much have equal length and tuned headers... Which way did you have to adjust the fuel and wastegate to get the power back ?
You had dual exhausts I assume ?

woodboat3 · #7 06-22-2011, 01:54 AM

forward facing equal length headers and 3 inch single out of the turbo that Yed into 2, I think 2 1/2 mufflers. Been a few years. boost was off by 2 1/2 pounds which was a lot because at the time I was running around 6. I know you aren't supposed to but I ended up moving the waste gate control line to the intake side of the intercooler and ended up on 9 to 9 1/2 at the intake. Pretty sure I had to fatten it up because final config I had the 22 Lb Hr injectors at %100 duty cycle with fuel pressure just under 50Psi. I think they were rated 22 at 40 Psi so I believe I was getting around 25Lbs Hr

ah-kay · #8 06-22-2011, 02:59 AM

Quote:

Originally Posted by leathermang

LOL,,,,, no,,,,he is kidding...
only in a situation where you had tuned exhausts would a hole mean less power... otherwise it would mean more power due to less restrictions... but increases the chance of CO getting into the car... so they need to be fixed for many reasons..

There is NO CO in diesel car. That is you can never commit suicide with a diesel fuel car due to CO poisoning. LOL

A hole, depending on how big, should have more power as there is less restriction.

woodboat3 · #9 06-22-2011, 03:19 AM

A quote:
An exhaust that is *too* free-flowing can result in the engine feeling 'gutless' at the bottom of the rev range. This is not always placebo, the gases leaving too early result in lower exhaust gas temps, therefore lower torque produced at those engine revs. This is only the case at low revs, because the very same exhaust design also results in higher flow at high revs, and lower EGTs there too. The only difference is that the lower EGTs are now welcome, because they are pushed below the maximum (safe point), while at low revs they were below the minimum (efficiency point).
http://www.max-boost.co.uk/max-boost/exhaust/exhaust.htm

All I know Is I personally put a free flowing muffler on a turbo car and got a huge decrease in performance until I retuned for the new flow. I was shocked as I expected instant horsepower gains.

woodboat3 · #10 06-22-2011, 03:25 AM

more stuff:
But here's a weird phenomenon: a discerning punter did a dyno run before/after fitting a cat-replacement pipe. Naturally he expected to see exactly how many horses the dreaded cat was robbing from him .
The result didn't make sense at all. With the cat replacement pipe (and same max boost), the engine was making less power. He repeated the measurements to make sure that heatsoak etc was not distorting the figures. But no - the cat (with all the passages and extra surfaces etc) was actually helping the engine make more power.

How could that be? There's no question that the cat was a restriction. There was also no question that the replacement pipe didn't let the engine make as much power as the cat did. There was no oxygen sensor downstream of the cat, so the engine management didn't know that the cat was missing.
http://www.max-boost.co.uk/max-boost/exhaust/exhaust_pulse_tuning.htm

woodboat3 · #11 06-22-2011, 03:41 AM

More stuff
http://www.autolounge.net/tech/exhaust.html

charmalu · #12 06-22-2011, 09:44 AM

Looks like these links are talking about gas engine performance. the OP was talking about his diesel engine performance.

So are you saying, no difference? all engine performance is the same?

Charlie

MTUpower · #13 06-22-2011, 09:55 AM

Forced induction gasoline engines and forced induction diesel engines do not share exhaust characteristics regarding back pressure. Total apples to oranges. FI diesel engines perform best with as little back pressure as possible. The hole has nothing to do with your loss of power most likely.

leathermang · #14 06-22-2011, 10:19 AM

Quote:

Originally Posted by ah-kay

There is NO CO in diesel car. That is you can never commit suicide with a diesel fuel car due to CO poisoning. LOL
A hole, depending on how big, should have more power as there is less restriction.

At least your last statement is true....

www.wtcexams.org/pdfs/diesel_engine_exhaust_emissions.pdf

http://www.yachtsurvey.com/carbon_monoxide_alert.htm

http://wiki.answers.com/Q/Can_you_get_carbon_monoxide_poisoning_from_diesel_semi_trucks
""It is completely possible to get carbon monoxide poisoning from a diesel engine in a road tractor. Contributing factors such as weather, temperature, and engine condition can greatly affect the chance of carbon monoxide poisoning. A good example of this is that a driver in a truck with an exhaust problem when it is cold and raining is at greater risk than the same person in the same truck on a sunny day. The reason for this is the barometric pressure holds the carbon monoxide closer to the ground and allows it to enter the truck.""

http://www.hdot.org/en/learning/myth-fact/diesel1
""A properly tuned diesel engine produces exhaust that contains about 1% carbon monoxide because the fuel is burned much more efficiently, especially when the engine is idling. That is why truck drivers can leave their trucks on all night without fear and why diesel-powered vehicles and equipment are favored in mining or underground situations.

Conclusion
Carbon monoxide is deadly in very small concentrations-as little as 4/10 of one percent (0.4%) or 4,000 parts in 1,000,000.
Although diesel engines do produce less carbon monoxide in their exhaust than do gasoline engines, they are equally as deadly as we will see in Part 2 of this series.""

Taking a chance on lives... based on the assumption that an engine is working perfectly ... which was the assumption you proffered... is not being prudent. They make a small amount normally....but can make more with any part of the system worn or out of adjustment...

ah-kay · #15 06-22-2011, 12:39 PM

Quote:

Originally Posted by leathermang

""It is completely possible to get carbon monoxide poisoning from a diesel engine in a road tractor. Contributing factors such as weather, temperature, and engine condition can greatly affect the chance of carbon monoxide poisoning. A good example of this is that a driver in a truck with an exhaust problem when it is cold and raining is at greater risk than the same person in the same truck on a sunny day. The reason for this is the barometric pressure holds the carbon monoxide closer to the ground and allows it to enter the truck.""

Leathermang: You omitted the first paragraph in your quote, by design or mistake?

http://wiki.answers.com/Q/Can_you_get_carbon_monoxide_poisoning_from_diesel_semi_trucks

"This is possible, but unlikely. Diesel engines detonate fuel using pressure and temperature, rather than with an artificial spark. This process operates with excessive oxygen, ensuring a much more complete combustion than what is typical in a gasoline engine. Typically, diesel exhaust contains some carbon monoxide, but the amounts are very minimal and not fatal for an otherwise healthy person."

In a nutshell, a hole in the muffler will not kill the OP, definitely not in a moving car.