Why is forced induction always mechanical?
08-15-2010, 12:31 PM
#26
That said, if an electric-driven supercharger could be made to work, it would be pretty neat, as you could easily switch the blower on and off at your leisure. Picture your RX-8 whirring down the road when some schmuck in a 350Z or Mustang tries to race you. You reach up, flip a switch Speed Racer-style, and leave him eating your dust.
08-15-2010, 12:40 PM
#27
I think one of the biggest problems that hasn't been addressed is the rechargeability of the battery. You can't just keep dumping in charge and pulling it back out as that'll massively shorten the lifespan of the battery. You'd need a special kind of battery (meaning expensive) to deal with memory issues and to hold enough charge. Perhaps a bank of the Tesla or Tango ones?
That said, if an electric-driven supercharger could be made to work, it would be pretty neat, as you could easily switch the blower on and off at your leisure. Picture your RX-8 whirring down the road when some schmuck in a 350Z or Mustang tries to race you. You reach up, flip a switch Speed Racer-style, and leave him eating your dust.
That said, if an electric-driven supercharger could be made to work, it would be pretty neat, as you could easily switch the blower on and off at your leisure. Picture your RX-8 whirring down the road when some schmuck in a 350Z or Mustang tries to race you. You reach up, flip a switch Speed Racer-style, and leave him eating your dust.
08-15-2010, 12:55 PM
#28
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any of you naysayers or yeahsayers actually run the numbers? its possible that running the SC electrical is actually less parasitic than running it off a belt. until someone runs the numbers you are all talking out of your ***.
its like the fuel cell at your home arguement. people say "oh its non sense to reform the NG into H2 to run through a fuel cell. you could just burn the NG for electricity. reforming it is 2 conversions so its more loss yadddyadda yadda"
well every study actually done now shows that its actually more efficient to reform it ,use the waste heat to heat your water and use the resultant electricity for fueling your electric car etc. than it is to burn the gas for heating the water and making electricity.
so somebody run the numbers
ill give you a hint though- thomas knight esuperchargers run off of separate batteries http://www.boosthead.com/product.php#
its like the fuel cell at your home arguement. people say "oh its non sense to reform the NG into H2 to run through a fuel cell. you could just burn the NG for electricity. reforming it is 2 conversions so its more loss yadddyadda yadda"
well every study actually done now shows that its actually more efficient to reform it ,use the waste heat to heat your water and use the resultant electricity for fueling your electric car etc. than it is to burn the gas for heating the water and making electricity.
so somebody run the numbers
ill give you a hint though- thomas knight esuperchargers run off of separate batteries http://www.boosthead.com/product.php#
08-15-2010, 01:11 PM
#29
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however it seems to me that you refuse to listen to anyone on this board trying to describe logic in automotive and electrical engineering, and are more interested in arguing any point with the same old sentence about store power in a battery and use brakes to charge it.
but i use the same old sentence because nobody has explained why it is wrong... people keep on saying it wont work... so i have to assume that they didn't read that sentence or i didn't explain it right.
The whole reason I made this thread is because i'm curious and I wan't to understand... So i'm going to keep asking until I do.
yes the alternator is on the same system as the compressor would be, but because the compressor isnt always running, it doesnt have to produce enough electricity to keep the compressor running indefinatly. maybe you'd need to replace your alternator, but the new alternator you'd use wouldnt need to put as much drain on the engine as a stock alternator + supercharger because it isn't always running the compressor.
its like a well. it fills up very slowly, but thats ok because you only take water out periodically.
Originally Posted by Triangle Man
as you could easily switch the blower on and off at your leisure.
Originally Posted by jasonrxeight
you need metal rods to handle that current.
It just baffles my mind that a little turbine sitting in your exhust can generate enough power to run the compressor (and still allow enough flow), but you need an enormus electric motor that drains your battery to run it electrically.
08-15-2010, 04:38 PM
#31
Momentum Keeps Me Going
I see reading this thread so much frustration with reality. However, the universe and its rules are rather unbending. Now consider how frustrated those engineers that are trying to develop useful and practical electric electric/hybrid vehicles must be...because they know the difficulties involved!
Gasoline (aka dead dinosours and ancient swamp ferns) has so much energy stored in it it really is unbelievably amazing. Even sucking just a little bit of that energy to power a vehicle provides power beyond most any fuel available, plus....in the form of gasoline's poop (exhaust gas) we can reaps loads more energy and more than enough to power turbos, for example!
On the other hand transporting and /or transfering the raw form of energy (electricity or really moving electrons) takes massive everything...batteries, heavy wires, then there's real problems switching and controlling them little electron devils traveling around inside everything. Perhaps a plasma drive has possibilities, if we could only contain it one day, but until we come up with a cheaper and more long lasting way to store the stuff (like some form of hugely effiecient large capacity super-capacitors - they don't wear out with repeated charge cycles like chemical storage) the purely electric anything is going to remain a engineering paradox for long distance transportation - or for powering superchargers, turbos, or anything else.
Gasoline (aka dead dinosours and ancient swamp ferns) has so much energy stored in it it really is unbelievably amazing. Even sucking just a little bit of that energy to power a vehicle provides power beyond most any fuel available, plus....in the form of gasoline's poop (exhaust gas) we can reaps loads more energy and more than enough to power turbos, for example!
On the other hand transporting and /or transfering the raw form of energy (electricity or really moving electrons) takes massive everything...batteries, heavy wires, then there's real problems switching and controlling them little electron devils traveling around inside everything. Perhaps a plasma drive has possibilities, if we could only contain it one day, but until we come up with a cheaper and more long lasting way to store the stuff (like some form of hugely effiecient large capacity super-capacitors - they don't wear out with repeated charge cycles like chemical storage) the purely electric anything is going to remain a engineering paradox for long distance transportation - or for powering superchargers, turbos, or anything else.
Last edited by Spin9k; 08-15-2010 at 04:41 PM.
08-15-2010, 04:42 PM
#32
I say take the car and turbo or supercharge it. Then make the body of the car a 100% solar pannel. Have a seperate computer, fuel system and electrocharger that you can use like NAAAWWWZZZ when you're racing or showing off. I'm assuming that my personal design would allow the renisis to go from 345 rwhp turbo to 1333 rwhp with the turbo/electrocharger both engauged. Just a thought.
08-15-2010, 05:09 PM
#33
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08-15-2010, 05:11 PM
#34
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the problem with electricity is that its not mechanic, to get it working you need wires. its not like a belt or highpresure exhaust gas.
08-15-2010, 05:43 PM
#35
I think the Prius Fanbois are using some sort of electrical forced induction...or maybe it's conduction...anyway, they're claiming soemthing like 500 whp, but they have to run Optima Yellow Tops..everything has a tradeoff.
08-15-2010, 06:34 PM
#37
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so somebody run the numbers
ill give you a hint though- thomas knight esuperchargers run off of separate batteries http://www.boosthead.com/product.php#
you typically cant run such a contraption for more than a few seconds, this is from Thomas Knight website:
You can expect 10 runs of 15 seconds from two fully charged car batteries like yellow tops.
08-16-2010, 12:38 AM
#39
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lol, it looks like the tomas knight system is like the nitrous that you find in video games that recharges when you go fast for a while :p.
How fast it is spinning doesn't really make a difference unless its acting like a flywheel, would it? If it is only drawing 5-10 hp from the engine, then it has at most 5-10 hp worth of power. Thats if it wasn't wasting any of the energy. so why can 5hp in a turbo power a compressor, but it'd take 50hp if it was electric?
How fast it is spinning doesn't really make a difference unless its acting like a flywheel, would it? If it is only drawing 5-10 hp from the engine, then it has at most 5-10 hp worth of power. Thats if it wasn't wasting any of the energy. so why can 5hp in a turbo power a compressor, but it'd take 50hp if it was electric?
08-16-2010, 12:42 AM
#40
lol, it looks like the tomas knight system is like the nitrous that you find in video games that recharges when you go fast for a while :p.
How fast it is spinning doesn't really make a difference unless its acting like a flywheel, would it? If it is only drawing 5-10 hp from the engine, then it has at most 5-10 hp worth of power. Thats if it wasn't wasting any of the energy. so why can 5hp in a turbo power a compressor, but it'd take 50hp if it was electric?
How fast it is spinning doesn't really make a difference unless its acting like a flywheel, would it? If it is only drawing 5-10 hp from the engine, then it has at most 5-10 hp worth of power. Thats if it wasn't wasting any of the energy. so why can 5hp in a turbo power a compressor, but it'd take 50hp if it was electric?
08-16-2010, 01:12 AM
#41
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I threw out the 30-60hp number to drive a supercharger. It depends on the type of blower, but typically it takes 15-20% of your engines power to actually drive the supercharger. This would obviously vary depending ont he gear ratio and engine airflow needs.
I remember with the procharger on the LS1 application and P1SC its something like 50hp to spin the impeller up to the 65k rpm with the resistance of average boost pressure.
I remember with the procharger on the LS1 application and P1SC its something like 50hp to spin the impeller up to the 65k rpm with the resistance of average boost pressure.
08-16-2010, 01:24 AM
#42
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hi
This is completely irrelevant to your post but I'm a new member and I joined because I had a few questions regarding my rx8. Embarrassing as is it to say, I don't know how to start a post to ask a question. I would really appreciate it if someone can help me by just pointing me into the right direction. Thanks a lot. 
08-16-2010, 01:57 AM
#43
This is completely irrelevant to your post but I'm a new member and I joined because I had a few questions regarding my rx8. Embarrassing as is it to say, I don't know how to start a post to ask a question. I would really appreciate it if someone can help me by just pointing me into the right direction. Thanks a lot.
Make sure you use the search button in the tool bar and see if your question has already been asked before you start a new thread .
08-16-2010, 02:39 AM
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Not that I'm a really hands-on kind of guy, but it doesn't take a genius to figure out simple laws of physics. If you're converting from mechanical to electrical there is always a loss ( no conversion is 100% efficient). Now converting back is the same thing would be even more lossy. There is simply no way that you can make it more efficient than mechanical. Not to contradict anyone here, but you don't have to run numbers to prove a fundamental concept.
Also, I guess I have to take a look at the Mercedes thing someone mentioned here, because I can't possible imagine a turbine spinning up to even 50k from 0 with any reasonable kind of lag, the motor would have to be immense. Ever see a electric go-kart engine that lies around 10hp or so? Would you stack that on top of your existing engine?
Also, I guess I have to take a look at the Mercedes thing someone mentioned here, because I can't possible imagine a turbine spinning up to even 50k from 0 with any reasonable kind of lag, the motor would have to be immense. Ever see a electric go-kart engine that lies around 10hp or so? Would you stack that on top of your existing engine?
08-16-2010, 05:25 AM
#45
Not that I'm a really hands-on kind of guy, but it doesn't take a genius to figure out simple laws of physics. If you're converting from mechanical to electrical there is always a loss ( no conversion is 100% efficient). Now converting back is the same thing would be even more lossy. There is simply no way that you can make it more efficient than mechanical.
Years ago I was struck by the "electric supercharger" idea until I realized that stick a fan in the middle of the intake, no matter how fast it turned, presented an obstruction. It might provide some increased intake at idle, but once intake velocity speeds up I don't know of any 3" fan than can move enough air to pressurize the intake. As has been mentioned, turbos spin in excess of 150000 rpm. To get this from an electrical system would require a drive ration increase off the motor and a large enough motor to spool it up fast enough. Could probably be done, but it has to suffer more loss than a mechanically driven system.
08-16-2010, 06:51 AM
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I realized that stick a fan in the middle of the intake, no matter how fast it turned, presented an obstruction. It might provide some increased intake at idle, but once intake velocity speeds up I don't know of any 3" fan than can move enough air to pressurize the intake. As has been mentioned, turbos spin in excess of 150000 rpm. To get this from an electrical system would require a drive ration increase off the motor and a large enough motor to spool it up fast enough
Like, i get the idea that this just wouldn't work. but i still dont get what makes it so un-doable.
08-16-2010, 07:08 AM
#47
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(from howstuff works)
A gallon of gasoline contains about 132x106 joules of energy, which is equivalent to 125,000 BTU or 36,650 watt-hours, so...
•If you took a 1,500-watt space heater and left it on full blast for a full 24-hour day, that's about how much heat (electrical energy) is in a gallon of gas.
....
Think how much battery mass to even get a fraction of that power stored! That's the problem with battery energy - it's impossible yet to store enough to do much useful for any length of time. What is needed is superior storage technology that doesn't yet exist.
A gallon of gasoline contains about 132x106 joules of energy, which is equivalent to 125,000 BTU or 36,650 watt-hours, so...
•If you took a 1,500-watt space heater and left it on full blast for a full 24-hour day, that's about how much heat (electrical energy) is in a gallon of gas.
....
Think how much battery mass to even get a fraction of that power stored! That's the problem with battery energy - it's impossible yet to store enough to do much useful for any length of time. What is needed is superior storage technology that doesn't yet exist.
Last edited by Spin9k; 08-16-2010 at 07:29 AM.
08-16-2010, 07:22 AM
#48
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(from howstuff works)
A gallon of gasoline contains about 132x106 joules of energy, which is equivalent to 125,000 BTU or 36,650 watt-hours, so...
•If you took a 1,500-watt space heater and left it on full blast for a full 24-hour day, that's about how much heat (electrical energy) is in a gallon of gas.
....
Think how much battery mass to even get a fraction of that power stored! That's the problem with battery energy - it's impossible yet get store enough to do much useful for any length of time. What is needed is superior storage technology that doesn't yet exist.
A gallon of gasoline contains about 132x106 joules of energy, which is equivalent to 125,000 BTU or 36,650 watt-hours, so...
•If you took a 1,500-watt space heater and left it on full blast for a full 24-hour day, that's about how much heat (electrical energy) is in a gallon of gas.
....
Think how much battery mass to even get a fraction of that power stored! That's the problem with battery energy - it's impossible yet get store enough to do much useful for any length of time. What is needed is superior storage technology that doesn't yet exist.
oh and a brand new car
just don't make it a damn electric anything please 
