blakerwry
Storage? I am Storage!
Check out this automobile tweak guide... There are sone excelent exhaust tips
;-)
;-)
For all you SUV lovers (and haters)
- Thread starter Handruin
- Start date
Buck
Storage? I am Storage!
Jake the Dog said:
Indeed. Many muffler kits are for show and don't improve performance. The mechanic doesn't actually spend the time to calculate exhaust volume and thus doesn't know the appropriate diameter, length, and muffling for the system. As you pointed out, standard systems are normally quite restrictive, this also helps the engine idle more smoothly and requires less material for crankshaft counterweights and flywheel mass.
What is worse is when people change intake/exhaust flow by increaseing valve size, but they don't compensate for this increased volume throughout the rest of the exhaust system.
Cliptin
Wannabe Storage Freak
Buck said:
Why? To both. What is back pressure? I can understand if the objective is to reduce the amount of exhaust that gets pulled back into the combustion chamber; but this does not seem to be what you are implying.
Fushigi
Storage Is My Life
Back to SUVs, my wife & I are considering what our next vehicle will be. Considering the occasional need to haul stuff from Home Depot and that if we're fortunate we'll also have the need for transporting baby necessities, we are considering getting a pickup, SUV, minivan, station wagon, or hatchback for our next vehicle. I would like AWD or 4WD or traction control to make the Chicago winters as easy as possible. I won't buy anything that gets less than 20MPG; 25+ preferred.
- Pickups are nice since there's no height restriction on what goes i the cargo area. However, to haul a family will require an extended cab, which adds cost and in many cases shortens the bed. Safety is fair at best. Handling is a little suspect in inclement weather regardless of powertrain unless the bed is weighted with a few hundred pounds. Fuel economy sucks.
- SUVs, specifically in the small to midsize category are pretty appealing. The agressive looks and availability of AWD/4WD fit the bill nicely. Cargo space is fine for 99% of our needs. Handling is also somewhat suspect, although some of the car-based designes are probably adequate. Safety is adequate for occupants. Fuel economy sucks.
- Minivans, as long as it has traction control or AWD, are one of the best solutions. Good cargo capacity, comfortable, adequate fuel economy, good safety.
- Station wagon. Not many options without getting to higher-end vehicles like Volvo. The leading contender would be the Subaru Outlack. But it's somewhat small and, beyond the powertrain, I've heard it's not that refined compared to the other Asian competition (specifically the cabin). Also seems a bit pricey for what you get. Fuel economy is adequate.
- Hatchback. This category of cars died off in the US for a while but has been seeing a resurgeance of late. Good fuel economy, adequate cargo space based on our needs, good safety.
My wife is, regardless, leaning towards an SUV while I am leaning towards a minivan or hatchback.
Of course, we more than likely won't be buying for a couple more years so there's plenty of time for us to make up our minds and reach an agreement. And for auto tech to change. Heck, an auto maker might actually remember the 60s & come out with a car with a trunk that's large enough to be useful for more than groceries.
- Fushigi
- Pickups are nice since there's no height restriction on what goes i the cargo area. However, to haul a family will require an extended cab, which adds cost and in many cases shortens the bed. Safety is fair at best. Handling is a little suspect in inclement weather regardless of powertrain unless the bed is weighted with a few hundred pounds. Fuel economy sucks.
- SUVs, specifically in the small to midsize category are pretty appealing. The agressive looks and availability of AWD/4WD fit the bill nicely. Cargo space is fine for 99% of our needs. Handling is also somewhat suspect, although some of the car-based designes are probably adequate. Safety is adequate for occupants. Fuel economy sucks.
- Minivans, as long as it has traction control or AWD, are one of the best solutions. Good cargo capacity, comfortable, adequate fuel economy, good safety.
- Station wagon. Not many options without getting to higher-end vehicles like Volvo. The leading contender would be the Subaru Outlack. But it's somewhat small and, beyond the powertrain, I've heard it's not that refined compared to the other Asian competition (specifically the cabin). Also seems a bit pricey for what you get. Fuel economy is adequate.
- Hatchback. This category of cars died off in the US for a while but has been seeing a resurgeance of late. Good fuel economy, adequate cargo space based on our needs, good safety.
My wife is, regardless, leaning towards an SUV while I am leaning towards a minivan or hatchback.
Of course, we more than likely won't be buying for a couple more years so there's plenty of time for us to make up our minds and reach an agreement. And for auto tech to change. Heck, an auto maker might actually remember the 60s & come out with a car with a trunk that's large enough to be useful for more than groceries.
- Fushigi
Buck
Storage? I am Storage!
Clippy, this might help:
The effects of back pressure
A muffler is an ambiguity in the performance world, as it can have both good and bad effects on power output. Back pressure is essential for peak power in almost any application, even 6000hp alcohol-burning Top Fuel dragsters have some built-in back pressure. Before we begin this discussion, take note that 1 atmosphere is the pressure that air is at naturally (uncontained) at sea level.
During the combustion process, when the exhaust valve is open, all of the compressed (and depeleted) air-fuel mixture spills out from the cylinders as fast as it can, through your exhaust manifold, into your catalytic converter(s), the muffler, and finally out the tail pipe. The problem with this is, just before your exhaust valve is about to close again, your intake valve opens up, allowing the fresh air-fuel mixture to rush into the cylinders. This is called overlap, and one of the things you take into consideration when choosing a cam, because it can be used to your advantage.
If there was no valve overlap, it would be 100% impossible to completely irradicate all of the spent gases from the cylinder. This has a two-fold effect on power output, depending on what RPM the motor is running at. At low RPM, this effect actually increases torque, because the least amount of compression is lost during the intake stroke, and the ratio of intake to exhaust gases is high. Unfortunately, as the RPMs increase, there is increasingly less time to evacuate the exhaust gases during the exhaust stroke, and more and more depleted air-fuel remains in the cylinders when the exhaust valve closes. The motor becomes incredibly inefficient near its readline. A motor designed for high-torque applications, such as towing, tends to exhibit less valve overlap then normal. The type of cam used in this application is often called an "RV" cam, because a recreational vehicle doesn't need horsepower as much as it needs low-end torque to get it moving.
Your car would also run terribly if there was too much valve overlap as well. When exhaust gases rush out of the cylinder, they create a low pressure area in the cylinder and the exhaust system, sucking the intake charge right into the cylinder, and right back out into the exhaust system. This is called scavenging. When that air spills out, so does the fuel it was carrying, so the O2 sensor reports a rich condition to the computer, often causing further decreases in the amount of fuel the computer injects. At low RPMs, this effect is most pronounced as there is sufficient time to suck out a significant portion of the intake charge, reducing torque. As the RPMs increase, however, the extra velocity imparted to the intake charge increases the amount that squeezes into the cylinder after the exhaust valve closes, as the valve closes so quickly at high RPMs that barely any intake charge escapes through the exhaust system.
No doubt you see the dilemna posed to designers when they choose a cam for the motor - the right combination of power must be achieved at the intended RPM range of the vehicle - if this is a tiny four cylinder, which must spin high RPM to make any power at all, you have to design in a higher amount of overlap. If the vehicle is mostly intended for low speed towing, you design in a smaller amount of overlap for more low-end grunt. Overlap is one of the reasons why the four-cylinder Acura Integra GS-R makes 170hp at almost 7000 RPM, and your 3.0L makes 171lb-ft of torque at 2000 RPM.
You can't control your overlap without changing the cams, but the effects caused by changing the back pressure are the same. When you reduce back pressure, it is equivalent to increasing valve overlap, and when you increase back pressure, it is the same as decreasing the amount of valve overlap. That's why some people will say, "you need a muffler for torque", or, "you'll have more high-end, but less torque, if you run straight exhaust". They are right, but a muffler's purpose is to reduce sound output, not horsepower! By reducing back pressure in an exhaust system, you increase high-end horsepower at the cost of low-end torque.
You can compensate for this by increasing the velocity of the intake charge. Increasing the intake velocity has the added side effect of increasing back pressure, because there is more air to be evacuated during the exhaust stroke. Note that if you increase intake velocity past the limits of the exhaust system, the gains you achieve are diminished to the point of being non-existent. That power will be there when you do upgrade the exhaust system, which is why something as simple as upgrading the exhaust system can result in huge horsepower gains.
You can decrease back pressure by increasing the size of your exhaust manifolds, or using separate tubes for each cylinder (called headers). Increasing the size of the exhaust pipe and decreasing its length also helps, as well as installing high-flow catalytic converters and mufflers. Of course, you could just cut them off. Although it is illegal in the United States to remove the catalytic converter in a registered vehicle, the muffler is a different story...
The effects of back pressure
A muffler is an ambiguity in the performance world, as it can have both good and bad effects on power output. Back pressure is essential for peak power in almost any application, even 6000hp alcohol-burning Top Fuel dragsters have some built-in back pressure. Before we begin this discussion, take note that 1 atmosphere is the pressure that air is at naturally (uncontained) at sea level.
During the combustion process, when the exhaust valve is open, all of the compressed (and depeleted) air-fuel mixture spills out from the cylinders as fast as it can, through your exhaust manifold, into your catalytic converter(s), the muffler, and finally out the tail pipe. The problem with this is, just before your exhaust valve is about to close again, your intake valve opens up, allowing the fresh air-fuel mixture to rush into the cylinders. This is called overlap, and one of the things you take into consideration when choosing a cam, because it can be used to your advantage.
If there was no valve overlap, it would be 100% impossible to completely irradicate all of the spent gases from the cylinder. This has a two-fold effect on power output, depending on what RPM the motor is running at. At low RPM, this effect actually increases torque, because the least amount of compression is lost during the intake stroke, and the ratio of intake to exhaust gases is high. Unfortunately, as the RPMs increase, there is increasingly less time to evacuate the exhaust gases during the exhaust stroke, and more and more depleted air-fuel remains in the cylinders when the exhaust valve closes. The motor becomes incredibly inefficient near its readline. A motor designed for high-torque applications, such as towing, tends to exhibit less valve overlap then normal. The type of cam used in this application is often called an "RV" cam, because a recreational vehicle doesn't need horsepower as much as it needs low-end torque to get it moving.
Your car would also run terribly if there was too much valve overlap as well. When exhaust gases rush out of the cylinder, they create a low pressure area in the cylinder and the exhaust system, sucking the intake charge right into the cylinder, and right back out into the exhaust system. This is called scavenging. When that air spills out, so does the fuel it was carrying, so the O2 sensor reports a rich condition to the computer, often causing further decreases in the amount of fuel the computer injects. At low RPMs, this effect is most pronounced as there is sufficient time to suck out a significant portion of the intake charge, reducing torque. As the RPMs increase, however, the extra velocity imparted to the intake charge increases the amount that squeezes into the cylinder after the exhaust valve closes, as the valve closes so quickly at high RPMs that barely any intake charge escapes through the exhaust system.
No doubt you see the dilemna posed to designers when they choose a cam for the motor - the right combination of power must be achieved at the intended RPM range of the vehicle - if this is a tiny four cylinder, which must spin high RPM to make any power at all, you have to design in a higher amount of overlap. If the vehicle is mostly intended for low speed towing, you design in a smaller amount of overlap for more low-end grunt. Overlap is one of the reasons why the four-cylinder Acura Integra GS-R makes 170hp at almost 7000 RPM, and your 3.0L makes 171lb-ft of torque at 2000 RPM.
You can't control your overlap without changing the cams, but the effects caused by changing the back pressure are the same. When you reduce back pressure, it is equivalent to increasing valve overlap, and when you increase back pressure, it is the same as decreasing the amount of valve overlap. That's why some people will say, "you need a muffler for torque", or, "you'll have more high-end, but less torque, if you run straight exhaust". They are right, but a muffler's purpose is to reduce sound output, not horsepower! By reducing back pressure in an exhaust system, you increase high-end horsepower at the cost of low-end torque.
You can compensate for this by increasing the velocity of the intake charge. Increasing the intake velocity has the added side effect of increasing back pressure, because there is more air to be evacuated during the exhaust stroke. Note that if you increase intake velocity past the limits of the exhaust system, the gains you achieve are diminished to the point of being non-existent. That power will be there when you do upgrade the exhaust system, which is why something as simple as upgrading the exhaust system can result in huge horsepower gains.
You can decrease back pressure by increasing the size of your exhaust manifolds, or using separate tubes for each cylinder (called headers). Increasing the size of the exhaust pipe and decreasing its length also helps, as well as installing high-flow catalytic converters and mufflers. Of course, you could just cut them off. Although it is illegal in the United States to remove the catalytic converter in a registered vehicle, the muffler is a different story...
Is it illegal to actually remove the cat? Here you can do whatever you like, as long as after the modification, the car is still below the government set limits when due for its annual MOT test.
http://www.ukmot.com/manual/6-4.htm
http://www.ukmot.com/manual/6-4.htm
Jake the Dog
Storage is cool
excellent explanation Buck 
now that variable cam timing isn't so cost prohibitive, you can see why it's become so popular.
NRG, I can't see how a modern engine can meet the current emission standards of any European country without it's exhaust gasses passing through a cat.
now that variable cam timing isn't so cost prohibitive, you can see why it's become so popular.NRG, I can't see how a modern engine can meet the current emission standards of any European country without it's exhaust gasses passing through a cat.
Buck
Storage? I am Storage!
Thanks Jake, it took a lot out of me.
I haven't got a clue, Jake. But there are people who do this. Perhaps the laws are written to accomodate old cars as well as new ones under the same test, and remember, a 20 year old Ford Fiesta makes as much pollution as 20 new ones. So maybe thats what happens. Or perhaps they mess with some other aspect of the engine when its time to get it checked? Or perhaps the whole system is corrupt :mrgrn:
slo crostic
Learning Storage Performance
A car running unleaded fuel without a catalytic converter actually produces the same amount of pollution as a car running on leaded fuel. The only difference is the types of pollutants produced. The lead in fuels used to bind with the lighter toxins, mainly benzine, and so prevent them from being emitted directly into the atmosphere. A 10 year old unleaded car, which is still running the original cat from the factory, will cause just as much pollution as a 20 year old leaded car because the catalytic convertor has passed it's useful lifespan. I think all cats should be manufactured in such a way as to physically collapse inside at the end of their useful life, so reducing performance of the car to the point where they have to be replaced.
Good idea, but if you think about it, the cost of a replacement cat on a cheaper car after 100,000 miles or however long the catalyst lasts will make it unfeasible and people will scrap the car - which may be working perfectly otherwise. This extra waste to be disposed of might be just as bad as the problem it intends to solve.
Buck
Storage? I am Storage!
You can always buy a diesel!
Buck
Storage? I am Storage!
NRG = mc² said:
You were talking about older cars, so I thought I would throw that in. As far as newer diesels go, the performance is amazing with the common-rail system. Developing fuel pressure independently of the injection cycle and independently of engine speed and load is such a simple idea, I'm surprised that wasn't in production sooner.
They certainly do drive better. I only once drove a diesel, an old one, and have been passenger in many a diesel, and I always thought they sucked big ones. Have to change gear every time you hit 2000rpm as it was all noise and no go after that, and also the fact that the noise and vibration can rattle your teeth out in an instant.
But then one day I rented a modern diesel and was impressed by its refinement and power. Sure, the turbo had a little lag, but it gave you time to hold on tight for when it spooled up. OK, it wasn't that fast but it felt very powerful and torquey :aok:
But then one day I rented a modern diesel and was impressed by its refinement and power. Sure, the turbo had a little lag, but it gave you time to hold on tight for when it spooled up. OK, it wasn't that fast but it felt very powerful and torquey :aok:
Not to mention the turbo whistle and the chirping of the wastegate reminded you of being in something from fast and furious, though you needed the window down to hear the wastegate. I did get some funny looks from people with the window open in early November, I must say.
Buck
Storage? I am Storage!
NRG = mc² said:
The feeling is fun, even when the speed isn't fast. My 300 Turbo Diesel easily revs to 3500-rpm (with lots of smoke) when it is warm. The turbo kicks in around 1800-rpm and then the fun begins! weeeeeeeeeeeeeeee
heh... this one I rented (Renault Clio dCi) only smoked on the overrun from high revs, or if you did a brutal downchange (i.e. stick it in 1st at 35mph). There was just a marginally sooty blast from the exhaust that could be seen from the rearview mirror if being followed by a car at night with its lights on.
The car had only done a couple of hundred miles - I actually rented it twice - one was when the particular shop had just opened and I must have been the first person to take it - it had 70 miles on the clock, next time I got one with around 300 miles on it. So much fun thrashing a virginal car that does not belong to you :bravo:
The car had only done a couple of hundred miles - I actually rented it twice - one was when the particular shop had just opened and I must have been the first person to take it - it had 70 miles on the clock, next time I got one with around 300 miles on it. So much fun thrashing a virginal car that does not belong to you :bravo:
Cliptin
Wannabe Storage Freak
Buck, Thanks for your time.
You will have to excuse my working ignorance. I have an academic knowledge of 2-cycle and 4-cycle IC engines (ie. I have designed cam profiles and know what the timing belt is for ) and fluid dynamics but no experience with the two together. In non-ideal problems they apparently influence each other. I'm not trying to pick apart the explaination just gain a complete understanding.
I'm still not exactly sure what it is physically that you are calling back pressure. Is this the pressure just outside the combustion chamber on the exhaust side that is a result of the gas mass-flow through the exhaust manifold?
One part I'm having trouble with is the part the cat and the muffler play in chamber pressure because they are at least partial obstructions to the gas flow.
So, If I understand correctly you want a small enough exhaust system to encourage a good mass-flow rate out of the chamber but not so small as to be restrictive when the mass-flow rate goes up due to increased engine RPMs. I suppose I might get better power in my car if I replaced the cat (original '88) and the muffler (rusty swiss cheese).
PS. I have seen designs for an exhaust system in which at a certain RPM an electronically actuated valve opens a second exhaust pipe from just behind the exhaust headers. I'm also surprised that electronically actuated valves have not been seen in production until recently.
You will have to excuse my working ignorance. I have an academic knowledge of 2-cycle and 4-cycle IC engines (ie. I have designed cam profiles and know what the timing belt is for
) and fluid dynamics but no experience with the two together. In non-ideal problems they apparently influence each other. I'm not trying to pick apart the explaination just gain a complete understanding.I'm still not exactly sure what it is physically that you are calling back pressure. Is this the pressure just outside the combustion chamber on the exhaust side that is a result of the gas mass-flow through the exhaust manifold?
I assume this is because the piston does not form-fit to the head on the exhaust stroke (or any other stroke)?Buck said:
Buck said:
Velocity or volume. I bet you are thinking turbo but what about larger intake headers.Buck said:
One part I'm having trouble with is the part the cat and the muffler play in chamber pressure because they are at least partial obstructions to the gas flow.
So, If I understand correctly you want a small enough exhaust system to encourage a good mass-flow rate out of the chamber but not so small as to be restrictive when the mass-flow rate goes up due to increased engine RPMs. I suppose I might get better power in my car if I replaced the cat (original '88) and the muffler (rusty swiss cheese).
PS. I have seen designs for an exhaust system in which at a certain RPM an electronically actuated valve opens a second exhaust pipe from just behind the exhaust headers. I'm also surprised that electronically actuated valves have not been seen in production until recently.
Buck
Storage? I am Storage!
NRG,
Thrashing rental cars is a joy. I've taken some 4 wheel drive Jimmys offroad, and oh boy what fun!
My diesel (1982) is running rich, so it smokes a bit more then usual, it also lowers my fuel economy a tad. But, the extra power when carrying four people up a steep hill on the freeway is nice. I can easily keep it at 65 or 70 on long hills.
Thrashing rental cars is a joy. I've taken some 4 wheel drive Jimmys offroad, and oh boy what fun!
My diesel (1982) is running rich, so it smokes a bit more then usual, it also lowers my fuel economy a tad. But, the extra power when carrying four people up a steep hill on the freeway is nice. I can easily keep it at 65 or 70 on long hills.
Cliptin
Wannabe Storage Freak
I'm plan vehicle purchases pretty far into the future but I'm looking seriously at a VW TDI.
Buck
Storage? I am Storage!
Correctclippy said:
Correct, thus you expend the excess gas by starting the process of filling the chamber with the combustion mixture.clip-doggie-snoop said:
They are partial airflow restrictions, but their design is unique. Remember, the design of an exhaust system is to expel and filter gas, plus to muffle noise, not to create an elaborate method of backpressure in order to boost performance. That is why the benefits of increasing exhaust flow at high-rpms (increasing high-end performance) is lost at low-rpms (loss of torque). Instead of using the exhaust system as a means of boosting performance, variable timing is much better. And as the name implies, it adjusts for the appropriate circumstance. Nonetheless, some car manufactures use the exhaust system to create their desired back-pressure at the expense of some performance.home-G-clip said:
That is why they developed variable intake manifolds. They adjust in size and shape to compensate for lower and higher pressures.clip-o-rama said:
You get the idea. But you can also see how just removing a muffler, or slapping on a louder sounding one isn’t the best way to increase performance. It is actually a rather uncalculated attempt at increasing performance.clipmeister said:
Buck, you speak German right?
Take a look at this (give it a while to upload)
http://www.rotting-energy.net/Forums/F360.avi
Does he say anything about the exhaust system on there?
Take a look at this (give it a while to upload)
http://www.rotting-energy.net/Forums/F360.avi
Does he say anything about the exhaust system on there?
Buck
Storage? I am Storage!
NRG, I get an error message when attempting to load that page:
The page cannot be displayed
There is a problem with the page you are trying to reach and it cannot be displayed.
--------------------------------------------------------------------------------
Please try the following:
Open the www.rotting-energy.net home page, and then look for links to the information you want.
Click the Refresh button, or try again later.
Click Search to look for information on the Internet.
You can also see a list of related sites.
HTTP 500 - Internal server error
Internet Explorer
The page cannot be displayed
There is a problem with the page you are trying to reach and it cannot be displayed.
--------------------------------------------------------------------------------
Please try the following:
Open the www.rotting-energy.net home page, and then look for links to the information you want.
Click the Refresh button, or try again later.
Click Search to look for information on the Internet.
You can also see a list of related sites.
HTTP 500 - Internal server error
Internet Explorer
Buck
Storage? I am Storage!
NRG = mc² said:
No problem.
Buck
Storage? I am Storage!
NRG = mc² said:
Sorry for being such a pain NRG, but now Windows Media Play tells me that the format is invalid (it is set to play avi files).
Buck
Storage? I am Storage!
NRG = mc² said:
None of the codec information shows up. Let me know what I need to do.
I take it the filesize is correct? If so head over to http://www.divx.com/divx/index.php and download DivX 5.02
Jake the Dog
Storage is cool
i can't play it either. I downloaded the entire file too.
Tea
Storage? I am Storage!
THE SCENE: Outdoors, a sunny day with fluffy clouds drifting by.. Three children are lying on a grassy bank, looking up at the clouds.
THE CAST: Charlie Brown, Linus, Schroder.
THE SCRIPT:
LUCY: What do yu see in the clouds, Schroder?
SCHRODER: I see a bust of the Ludwig van Beethoven, at the climactic creative moment where his conception of the Pastoral Symphony crystalises into a series of rustic dance motifs intertwining into the climactic scenes of the last movement with the drama of the storm overlaying all. What do you see in the clouds, Lucy?
LUCY: I see an allegorical dichotomy between the self-directed mastery of Nietsche and the pan-humanity of Guatama Budda as expressed by his deciple Ghandi - that is him over there on thge left, Schroder - symbolic of the search for a unity between national identity and self-realisation.
(A pause)
LUCY: What do you see in the clouds, Charlie Brown?
CHARLIE BROWN: I was going to say I saw a doggie and a horsie but I changed my mind.
---------------
(I believe Tannin had intended to contribute to this thread. :wink: )
THE CAST: Charlie Brown, Linus, Schroder.
THE SCRIPT:
LUCY: What do yu see in the clouds, Schroder?
SCHRODER: I see a bust of the Ludwig van Beethoven, at the climactic creative moment where his conception of the Pastoral Symphony crystalises into a series of rustic dance motifs intertwining into the climactic scenes of the last movement with the drama of the storm overlaying all. What do you see in the clouds, Lucy?
LUCY: I see an allegorical dichotomy between the self-directed mastery of Nietsche and the pan-humanity of Guatama Budda as expressed by his deciple Ghandi - that is him over there on thge left, Schroder - symbolic of the search for a unity between national identity and self-realisation.
(A pause)
LUCY: What do you see in the clouds, Charlie Brown?
CHARLIE BROWN: I was going to say I saw a doggie and a horsie but I changed my mind.
---------------
(I believe Tannin had intended to contribute to this thread. :wink: )
Buck
Storage? I am Storage!
NRG = mc² said:
Nope, and I installed the DivX program. I still get an error message. Perhaps it is the fact that I'm using Windows Media Player.
How about you give me a link to the page, and I download the avi file separately?
Buck
Storage? I am Storage!
Sort of like what I did here:
http://www.mittelsmann.net/music.htm
http://www.mittelsmann.net/music.htm