A&Q about 350Z
Q:
My bad i was vague on the diesels being sow part... i know that diesels can be damned fast but the engines just don't rev enough to please me :P something like 9500 RPM is what i like to see lol.
although yes i would love to have a small get up and go diesel car with great gas milage and HP
A:
9500 RPMS is music to my ears too, man. I'm hopelessly in love with classic american iron, so I guess I'm limited to about 6500
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Is it a breathing problem with diesels or the fuel burning rate that limits diesels putting out high HP in the upper RPM range say 7500-9500?
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Its a compression and fuel burn rate issue that keeps it lower. Some of the older Chevy 6.2/6.5 non-turbo diesels that were in the 16.5:1 range could go 3800 or more.
Its also a factor of the high-pressure hydraulic fuel pumps. They can get damaged after a certain RPM based on their individual designs.
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Ethanol production from corn and other cash crops will also help the farmers who need more areas to market their crops. I agree it is not the final solution, but when you can clean up the emissions and help out the farming industry; it seems like a good place to start !!!
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Actually, leaving a small ammount of water in the alcohol helps the fuel burn smoother, 160 to 180 proof burns smoother in engines than pure 200 proof alcohol, however the remaining water means that it will not mix with gasoline (it's also easier to produce fuel grade 160 proof alcohol at home with a very basic still, than it is to make pure 200 proof alcohol).
Legally, you can produce alcohol in any home, so long as you have written the ATF for an experimental alcohol liscense (which means that you cannot sell the alcohol you produce, or drink it) the more you produce the more expensive the liscense is - but if you just want to experiment with a small still to make ebough to run your lawnmower, it's not too expensive - and you supposedly get your money back if you dismantle your still and stop making alcohol.
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I have a couple questions, but I have practically no knowledge of the scientifics of fuel so if these are completely ignorant forgive me.
first one guy posted that his deisel got 24 mpg's but alot of cars now get way better gas mileage than that so how is it actually more fuel effecient other than burning cleaner?
second at just about any gas station I go too diesel is always substantially more expensive than gasoline so to fill up the same size tank you would still be paying more with deisel.
my last questions is on the several statements on being able to make fuels in your own home with like motor oil and vegetable oil and so on how is this done and if it is diesel or biodiesel that can be put straight into your deisel engine and you would be ready to go there is no fancy modification to the fuel needed?
Once agian, sorry if these are dumb questions but I know nothing of deisel and was curious. thanks
A:
Diesels Can Make Amazing power. Because of the fact that Diesels are always running "lean" all you have to do to make more power is add more fule. I support the diesel movement because when you need the power it is there and when you need the fule economy it is there. All you need to add serious power to any diesel is more boost (if it is turbo or supercharged) and more fule (via larger injectors). Gasoline you have to worry about alot of other things.
Another reason people dont like diesels is because more often than not they are alot louder than gasoline engines.
as far as Ethnyl. Would you have to be 21 to fule up at the gas station?
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Not ignorant at all, they are very valid questions.
I was comparing trucks. There was a diesel truck that was running low 12s in the 1/4 mile. It got 24 mpgs on the street which is pretty impressive compared to a gas engine of the same output. That might by a 6 or 7 mpg truck if it were gas. While 24 MPGs isn't great, when its in a 4300-lb truck that gets low 12s, its amazing.
In general yes. It tends to dance around in price, but in general diesel is cheaper to produce, ship, store, and the taxes are often lower per gallon. When a gallon gasoline costs $1, a gallon of diesel SHOULD cost about 60 cents. Demand for diesel in the commercial industry and the taxes that the DOT/DMV imposes on commercial trucks help keep them high. Its also partly the fact that diesel vehicles only comprise a small percentage of non-commercial vehicles.
The real smack in the face is that the Volkswagen TDI diesels when compared to the Hybrids presents an interesting contrast. The TDI cars typically get near 50 mpg, while the Hybrids are turning in less than ideal 35-45 mpgs. The TDIs have more power, and that power is just as available after a climb into the rockies, unlike the Hybrid which would drain the batteries leaving you to fend with the engine alone... all 32 hp of it or whatever it is. The TDIs have 90 hp. Its a painful comparison for most, but I've thought Hybrids were a waste from the beginning. I won't go into it because for some reason I have trouble conveying my ideas without ruffling feathers.
For the most part, diesels will burn anything close to diesel fuel within reason. Its important to note the gasoline is gasoline; federally mandated to conform to a specific chemical makeup. Diesel refers to a class of fuels that burn in diesel engines. It just so happens that all diesel fuel was universalized since what we commonly find at diesel pumps was the most stable, easiest way to make a reliable fuel. Since things like vegetable oil, kerosene, jet A, jet B, and fuel oil share many properties in common, they will all burn very comparably in diesel engines. You can't just pour some Wesson in your tank and expect it to work, but I don't know the finer points of how its refined into fuel. Someone has posted on the net how to do it, but its not something that a home-brew operation could adequately support.
In general, all things considered, diesel engines of the same output can experience twice the mileage of their gas counterparts, with fewer parts (no ignition system), and often more streetable manners. They do make a touch more noise and tend to have slightly shortened maintenance periods, but I've actually talked to people who drove a diesel and didn't even know it. Often times the TDI volkswagens are so transparent that drivers don't even know they're driving a diesel.
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This is progress.
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Diesel engines must have a specific fuel much like gasoline engines. For example, you can't burn ethanol in them without modifying the engine or the fuel.
Diesels are better engines than SI engines, the reason SI are still used is because of:
1. They run of a different fuel fraction.
2. They are cheaper to buy/produce.
3. They are lighter/smaller.
4. Exhaust emissions can be cleaned with a catalytic converter.
The modern diesel is however turbocharged and intercooled which decrease their size/weight in comparison to their power output, it together with modern electronic fuel systems also makes them cleaner and with the particle filters availible they are a better option than hybrid cars except in inner cities where the traffic can stand still for long periods of time.
Diesel engines can also be made so that they last longer, so even if they are more expensive to buy the savings done later is more than enough to make them more economical.
As for engine speed that was usually limited by the fuel system, today higher engine speeds is possible but it's still limited by the combustion in the cylinders but a max speed of 6000 rpm as with most gasoline engines is possible if one wants to. Power is hoever mostly extracted by using turbocharging, since very high boost pressures can be used without having to worry about engine knock.
As for hydrogen fuels, there is today no good options for a massproduction of the fuel. Hydrogen is today usually produced from petroleum by cracking of the hydrogen atoms. That means that keep using gasoline and diesel will be better than using hydrogen.
Ethanol can be used on the cars currently in production with modifications done to the fuel system and engine management system. Today most ethanol runnign vehicles are of "flexifuel" type which means that they can run on normal gasoline, E85 or any blend in between. This does however offer a drawback, since we can't optimise the engine for the higher octane E85. Ethanol does also seem better than it actally is (I blame the lobbyists for that), there are problems with some of the exhaust emissions caused by it, and not all of them are tailpipe emissions but evaporative emissions and emissions from the ethanol production. Another problem with ethanol is the current production methods based on corn; with the current corn production methods fossil fuel must be used in the production so that the gains from the ethanol are small. For example so do current production ethanol only decrease greenhouse gas emission by around 20%. These emissions gains can however be increased to over 100% with a better fuel production methods. However, I would say that methanol is a more interresting fuel if we want low emissions, the problem with methanol is that it's very hard on the fuel system and engine.
Making your own fuel as some people has mentioned is not cost effective, its actually cheaper to buy massproduced fuel.
E85 has an energy content of about 31 MJ/kg, compared to 43-44 MJ/kg for gasoline or around 42 MJ/kg for diesel. This results in a fuel comsumption increase by around 35-40% when going from gasoline to ethanol. That is however not that big of a problem unless we talk airplanes and helicopters where the extra mass of fuel would mean a reduction of cargo capacity. But that was also one of the reasons why it wasn't introduced around 1920.
Cold start problems of some fuels can be solved with addetives, a separate fuel tank for a special cold start fuel or higher compression ratios. Preheating of the engine is also a good method, but it has the drawback that you must plan your trip so that you can set the heater.
As for fuel cells, I think it will take some time until they become a real option. Some say that it will just take a few years know; well that was what they said 100 years ago too...
As for fuels based on petroleum I don't think they are a good option in the long run, but they can be used as addetives. These fuels can also be made on a syntheic way, but that is associated with high costs and low volume production.
In hybrid veihicles gas turbine engines should also be a possible option. They are light and small, can offer a low fuel consumption, a lot of money on developement is already spent by the manufacturers of airplane and marine turbines and it should be possible to make an engine that can run on a lot of different fuels.
As I see it, the best near future fuel option for engines would be diesel engines running on some sort of biological based fuel, or methanol burning spark ignited engines.
A:
When you say that people can drive a diesel car with out even realizing it does that mean that the noise of the diesel engines are dampened on cars that run diesel cause I hate the sound of a diesel truck they are nothing in contrast to a good v8. But either they are able to silence it in cars or I can't say that I've ever come across a diesel car before.
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As technology improves, they are able to do amazing things to find out what makes engines work. In the case of diesel engines one of the main problems was the noise created by injecting fuel directly into the superheated air. What makes old diesels so loud is the fact that they are basically operating completely on the premise of "ping". One of the big discoveries made in the last couple decades is how the flame front acts under certain circumstances.
In the past, diesel fuel was injected into a swirl chamber adjacent to the cylinder. The mass of fuel used this chamber, the swirling air, and the heat to create combustion. Now that the functions of the explosion have been studied and the technology is available for direct injection, the swirl chamber is a thing of the past for most diesels. Instead of injecting all the fuel at once, it injects it over a longer period of time. This prevents the loud explosion that makes the diesel noise. It also prevents overloading of fuel that can create the black smoke. As a by product of this more accurate injection, the burn rate is also extended slightly. One of the reasons diesels make so much torque is that they provide pressure on the piston longer than a gasoline engine. In a gasoline engine the gas explodes and lasts about 15 degrees of crank rotation. With a diesel, it lasts 20-40 degrees of crank rotation, meaning that there is still significant pressure on the piston at a point where it has its greatest advantage on the crank; in the 30-50 degree range.
They've also gone to great lengths to use sound deadening in the cabins to make it almost inaudible inside the vehicle. I had a 95 Ford with a Powerstroke. It was the cheapest possible version with no carpet, just rubber floors, no A/C, the analog AM/FM radio, and nothing else. Just a truck, a 'stroke, and rubber floors. The 95's were also known for their noise levels, but inside the truck at highway speed you couldn't hear the engine at all.
I'll bet you've seen a thousand Duramax trucks but couldn't tell they were diesels until you saw the badge on the fender. Just this past thursday I passed a VW TDI beetle and I couldn't hear the engine at all with the window down going 45.
To answer your question, most of the noise reduction has come from internal technology. They're also getting much higher output from much smaller displacements which tend to make less noise. The other dead giveaway that its a diesel is how it drives. Older (80's and earlier for example) diesels were torquey, but sluggish and had a different "feel" to them. The advancements in how we get diesel to burn have made them all but transparent to the driver who is used to gasoline.
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well i shouldnt have said all diesels are loud. SOme newer diesels are decently quiet and others are still pretty loud. example being.
My grandathers 2005 GMC Serria 2500HD is diesel. nearly as quiet as his 2002 GMC serria 1500 that was gasoline.
However. My friends dad has a 2003 Ram 2500 with the Duramax or w/e dodge has. loud as the old diesel ford F series.
Also, Smaller diesles are not near as loud. The old diesel Benz where prety quiet, not as quiet as gasoline cars of their time but still pretty quiet, quieter than alot of these "Sport" compacts ridding around with walmart 3" exausts and glass pack mufflers.
With enough dampening and a good muffler i'm sure smaller displacement diesel could be as quiet as the cadilacs that are so quiet you dont even know they are running from the inside.
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Thats cool. The reason I asked is because after reading all the posts I've become interested in maybe getting a diesel car if the mileage is as great as everyone says that would be great for getting around town and long trips then I would just drive my camaro on the strip and 3000gt when I go rallying to save gas. Do all manufacturers make diesel cars I'm not a truck person I don't like trucks my self out side of going mudding with I do in my 3000gt anyway but if not which manufacturers do I saw a lot of vw tdi being mentioned but is that the only choice. Plus I don't really want to pay on it for the rest of my life so examples of cheaper models would be apreciated.