Why is forced induction always mechanical?
08-17-2010, 04:11 PM
#101
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There is no question as to which is more efficient over-all... obviously mechanical. The question is: why is electrical so not-doable? Even with the inefficiencies, there are advantages to electical that are appealing if it were do-able.
08-17-2010, 06:28 PM
#102
Apparently, Volvo is working on uisng and electric driven supercharger device to increase low end boost and efficiency before the turbo spools in - my guess is to use a low displacement engine for fuel efficiency, use the electric fan to get off the line until a relatively large turbo builds boost.
This since Geely (China) now owns Volvo.
This since Geely (China) now owns Volvo.
08-17-2010, 07:16 PM
#104
1) yes... there is. but how much is actually being captured in a turbo? 2) There is no question as to which is more efficient over-all... obviously mechanical. The question is: why is electrical so not-doable? Even with the inefficiencies, there are advantages to electical that are appealing if it were do-able.
2) Not obviously, and we have far too many threads making the various arguments to "resurrect our bad experiences" with them here.
If there advantages to the electrical approach, I already laid the process groundwork for you to follow in making your assertion so do your research, present your findings, and we can all debate it further. Otherwise, we are all simply theorizing and I will hafta agree with Team on this one.
08-17-2010, 07:54 PM
#105
08-17-2010, 11:15 PM
#106
the giant tastetickles
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I went out and play with my electric RC 1/10 and then my nitromethane RC 1/10. Battery power just plain sucks and doesn't last. This may have little to do with anything on this thread but rev-heads will always be rev-heads, we love smoke, noise and smell of gas. You can have very efficient electric running device but charging it takes way too long and fast charging kills batteries fast.
08-18-2010, 02:02 PM
#107
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1) More than if there were no turbo on the engine in the first place.
2) Not obviously, and we have far too many threads making the various arguments to "resurrect our bad experiences" with them here.
If there advantages to the electrical approach, I already laid the process groundwork for you to follow in making your assertion so do your research, present your findings, and we can all debate it further. Otherwise, we are all simply theorizing and I will hafta agree with Team on this one.
2) Not obviously, and we have far too many threads making the various arguments to "resurrect our bad experiences" with them here.
If there advantages to the electrical approach, I already laid the process groundwork for you to follow in making your assertion so do your research, present your findings, and we can all debate it further. Otherwise, we are all simply theorizing and I will hafta agree with Team on this one.
1) I think I didn't really explain myself properly... I mean how much power does the turbo take from the engine to run the compressor... aka... if the turbo was to power the wheels rather than power a compressor, how much power would it make? aka how power does it take to run the compressor a turbo drives?
2)it is obvious that going from mechanical to electrical and back to mechanical is theoritaclly always less efficient (and it currently seems it is also practically less efficient). but im not worried about efficiency here.
arg... it looks like im really bad at explaining myself. People are being helpful and answering... but they aren't answers to what I asked, so I think I must just not be asking the questions right... but I don't know how else to ask.
Anyways, I'll try to find my answers around other places since people seem to be getting tired of this.
08-18-2010, 04:56 PM
#109
arg... it looks like im really bad at explaining myself. People are being helpful and answering... but they aren't answers to what I asked, so I think I must just not be asking the questions right... but I don't know how else to ask.
Anyways, I'll try to find my answers around other places since people seem to be getting tired of this.
Here's the main issue
3 Third Law: The mutual forces of action and reaction between two bodies are equal, opposite and collinear. This means that whenever a first body exerts a force F on a second body, the second body exerts a force −F on the first body. F and −F are equal in magnitude and opposite in direction. This law is sometimes referred to as the action-reaction law, with F called the "action" and −F the "reaction".
Example electric supercharger takes power from? Battery's or alternator. Batteries need to be charged alternator will take power from engine to charge. Regenerative braking. more weight to the vehicle requiring the engine to work harder to move the vehicle. Regenerative braking is not always on, there for you will have down time in which the batteries will drain and need to be charged from an external source.
One day maybe we will be able to break these laws but at the present time for every action comes a reaction... aka energy cannot be created or destroyed.
I hope that answers your question.
08-18-2010, 05:02 PM
#110
....... it looks like im really bad at explaining myself. People are being helpful and answering... but they aren't answers to what I asked, so I think I must just not be asking the questions right... but I don't know how else to ask.
Anyways, I'll try to find my answers around other places since people seem to be getting tired of this.
Anyways, I'll try to find my answers around other places since people seem to be getting tired of this.
In this exercise, those involved or watching have an opportunity to see very clearly all the considerations that must be taken when developing a new product offering for any vehicle or market. This goes to the title of this very thread.
Whereas my associate here, MazdaManiac, is a man of ideas I am a man of turning the abstract into the concrete by dealing with issues of procurement, cost, marketability, sales, delivery, etc. He is the research, I am the development (so he says) of BHR.
As such, I am treating you as the "MazdaManiac" in this equation.
Last edited by Charles R. Hill; 08-18-2010 at 05:05 PM.
08-18-2010, 06:16 PM
#111
Extraordinary Engineering
You are doing fine at explaining yourself and posting extemporaneously. What I am trying to do is encourage you to pursue your theories in a less abstract manner by researching the arguments you are pondering because, in doing so, you will realize that much of what is being debated has been discussed over the history of this particular forum. Nobody is getting tired of this, btw.
In this exercise, those involved or watching have an opportunity to see very clearly all the considerations that must be taken when developing a new product offering for any vehicle or market. This goes to the title of this very thread.
Whereas my associate here, MazdaManiac, is a man of ideas I am a man of turning the abstract into the concrete by dealing with issues of procurement, cost, marketability, sales, delivery, etc. He is the research, I am the development (so he says) of BHR.
As such, I am treating you as the "MazdaManiac" in this equation.
In this exercise, those involved or watching have an opportunity to see very clearly all the considerations that must be taken when developing a new product offering for any vehicle or market. This goes to the title of this very thread.
Whereas my associate here, MazdaManiac, is a man of ideas I am a man of turning the abstract into the concrete by dealing with issues of procurement, cost, marketability, sales, delivery, etc. He is the research, I am the development (so he says) of BHR.
As such, I am treating you as the "MazdaManiac" in this equation.
08-18-2010, 08:46 PM
#113
08-18-2010, 08:48 PM
#114
08-19-2010, 08:35 PM
#115
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Well... if noone is geting tired of this... *evil cackle* :p
I am getting my friend who is in mechanical engineering (and a bit of a car guy himself) to help me with some numbers for all of this. Just to get this strait... you don't have to dumb down the science for me, i did a bit of engineering and ended up in comp sci, so its not like i don't know physics... its just that i don't know cars :p. My rx-8 (hence why im on here) is the first car i've owned myself, so I haven't done any tuning myself before... so you'll have to forgive me for my lack of common-car-sense :p.
Yes, but the alternator is working all the time, the electric motor isn't. FI is mostly useful at WOT... because if you're not WOT in a NA car you can get more power just by opening the throttle. How long do you drive with the hammer down? an equilibrium of 90sec charge for 20 sec boost sounds acceptable to me...
There is more to the problem than just the 3rd law of motion, if you remove the turbine in a turbo and replace it with an electric motion, what is the additional force acting against the electric motor that wasn't acting on the turbine? Remember, im not concerned with fuel efficiency. Recharging just has to be efficient enough maintain an equilibrium (like what i mentioned above).
Someone mentioned some car company was going to use electric compression to power FI until a turbo spun up (rumour)... that got me thinking (and maybe this is what they ment)...
Use a normal mechanical turbo... but attach an electric motor to the shaft that powers the compressor. The electric motor can take some load off the turbine so that it can spool up faster. When the turbo is spooled up, the electric motor disengages, so that it used only briefly and doesn't need to be as powerful.
You can regulate the amount of boost produced by introducing restience against the turbo by using the motor as a generator. That would slow the turbo and also recharge the battery.
I am getting my friend who is in mechanical engineering (and a bit of a car guy himself) to help me with some numbers for all of this. Just to get this strait... you don't have to dumb down the science for me, i did a bit of engineering and ended up in comp sci, so its not like i don't know physics... its just that i don't know cars :p. My rx-8 (hence why im on here) is the first car i've owned myself, so I haven't done any tuning myself before... so you'll have to forgive me for my lack of common-car-sense :p.
There is more to the problem than just the 3rd law of motion, if you remove the turbine in a turbo and replace it with an electric motion, what is the additional force acting against the electric motor that wasn't acting on the turbine? Remember, im not concerned with fuel efficiency. Recharging just has to be efficient enough maintain an equilibrium (like what i mentioned above).
Someone mentioned some car company was going to use electric compression to power FI until a turbo spun up (rumour)... that got me thinking (and maybe this is what they ment)...
Use a normal mechanical turbo... but attach an electric motor to the shaft that powers the compressor. The electric motor can take some load off the turbine so that it can spool up faster. When the turbo is spooled up, the electric motor disengages, so that it used only briefly and doesn't need to be as powerful.
You can regulate the amount of boost produced by introducing restience against the turbo by using the motor as a generator. That would slow the turbo and also recharge the battery.
08-19-2010, 09:55 PM
#116
isays
from my understanding is that the majority of R&D at the moment by major car manufacturer are aimed at your concept of FI using eletric,
However rather then using a FI eletrical component that is equivelent of a turbo, SC
They are using a additional eletrical motor to power the car, thus you have all these new ranges of hybrid having multiple driving mods such as fuel saving, sports etc.
Your ideas of a eletricial support to current FI application is very well placed, with eletrical help we can almost eliminate low end boost lag, however the trouble is, as for majority of ideas for automobile industry is the costs involved in development and production, and whether it will be worthwhile for current car owners to throw the cash over traditional and proven FI setups.
from my understanding is that the majority of R&D at the moment by major car manufacturer are aimed at your concept of FI using eletric,
However rather then using a FI eletrical component that is equivelent of a turbo, SC
They are using a additional eletrical motor to power the car, thus you have all these new ranges of hybrid having multiple driving mods such as fuel saving, sports etc.
Your ideas of a eletricial support to current FI application is very well placed, with eletrical help we can almost eliminate low end boost lag, however the trouble is, as for majority of ideas for automobile industry is the costs involved in development and production, and whether it will be worthwhile for current car owners to throw the cash over traditional and proven FI setups.
08-25-2010, 12:51 PM
#119
2009 RX-8 Touring
yes... there is. but how much is actually being captured in a turbo? A turbo, like a super, is leeching energy from the engine, not running its own little engine. how much power does the turbo actually capture?
There is no question as to which is more efficient over-all... obviously mechanical. The question is: why is electrical so not-doable? Even with the inefficiencies, there are advantages to electical that are appealing if it were do-able.
There is no question as to which is more efficient over-all... obviously mechanical. The question is: why is electrical so not-doable? Even with the inefficiencies, there are advantages to electical that are appealing if it were do-able.
That being said, there are a lot of engines with poorly-designed turbo setups, especially ones with aftermarket kits on them.
Anyway, electrical supercharging is doable, but you'd have to have an enormous alternator to generate enough electricity to run the compressor fast enough to make a meaningful difference in horsepower. The primary advantage to electrical supercharging is that you can store the electricity and use it to spool the compressor much sooner than an exhaust-driven turbocharger would spool -- but if you're going to store electricity, you can just as easily use it to move the car directly using an electric motor, and it will be able to use that energy more efficiently too.
08-25-2010, 01:16 PM
#120
I divide by zero
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Because of this; Look how big it is (my hard hat for scale):
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08-25-2010, 01:24 PM
#121
No, a turbocharger doesn't leech energy from the engine. It harvests energy from the hot gases expanding in the exhaust manifold, energy which would otherwise go out the tailpipe and be wasted. Any engine with a well-designed turbo setup will make the same horsepower as a test engine with an externally-powered compressor feeding air into it.
That being said, there are a lot of engines with poorly-designed turbo setups, especially ones with aftermarket kits on them.
Anyway, electrical supercharging is doable, but you'd have to have an enormous alternator to generate enough electricity to run the compressor fast enough to make a meaningful difference in horsepower. The primary advantage to electrical supercharging is that you can store the electricity and use it to spool the compressor much sooner than an exhaust-driven turbocharger would spool -- but if you're going to store electricity, you can just as easily use it to move the car directly using an electric motor, and it will be able to use that energy more efficiently too.
That being said, there are a lot of engines with poorly-designed turbo setups, especially ones with aftermarket kits on them.
Anyway, electrical supercharging is doable, but you'd have to have an enormous alternator to generate enough electricity to run the compressor fast enough to make a meaningful difference in horsepower. The primary advantage to electrical supercharging is that you can store the electricity and use it to spool the compressor much sooner than an exhaust-driven turbocharger would spool -- but if you're going to store electricity, you can just as easily use it to move the car directly using an electric motor, and it will be able to use that energy more efficiently too.
I was under the impression that if you were to take energy from something and use it that you could not replace it with the same amount of energy.
For example a turbine spinning from exhaust gases, yes it will blow by but you are restricting flow which will impede power.
Hmmm maybe I'm wrong.
08-25-2010, 02:02 PM
#122
Extraordinary Engineering
I tried to reason it out...
Then just looked it up - four parts... enjoy!
http://www.turboclub.com/turbotech/TurboFun1.htm
Then just looked it up - four parts... enjoy!
http://www.turboclub.com/turbotech/TurboFun1.htm
Last edited by DarkBrew; 08-25-2010 at 03:18 PM.
08-25-2010, 03:01 PM
#123
SPOOLN8
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hahah, so this is just to illustrate a point ( I know it's way out of scale compared to a car).... but it takes a 600HP electrical motor to spin that turbine enough to make only 100psi on a 5" compressor outlet... and 4160volts!! compared to the 14v your car has supplied to it..... go figure, the amount of electrical input is MASSIVE compared to the amount of pressure it creates... but electricity happens to be in no shortage for this mother as I happen to work at a 900MW powerplant.
Last edited by RotaryMachineRx; 08-25-2010 at 03:05 PM.
08-25-2010, 03:25 PM
#124
I tried to reason it out...
Then just looked it up - four parts... enjoy!
http://www.turboclub.com/turbotech/TurboFun1.htm
Then just looked it up - four parts... enjoy!
http://www.turboclub.com/turbotech/TurboFun1.htm
My point is you cannot create energy. It needs to come from somewhere. It needs to take it from somewhere. Even if it multiplying it exponentially it needs to come from somewhere.
