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Toyota once built two turbochargers into the Supra, one that delivered low boost, initially, while the larger turbocharger caught up.
This lag in turbochargers is avoidable by using a supercharger. A google search turned up several electric superchargers. Lets combine the two, in one compact unit and
create a supercharged turbocharger. Both would use the same compressor, but to avoid the lag inherent in turbocharger, an electric motor would be attached to the to the turbocharger for power in those vital five to ten seconds. The electric motor would cut out after the turbocharger achieves full boost
electric supercharger
http://www.electric...r-com/Autoframe.htm [senatorjam, Aug 29 2002, last modified Oct 04 2004]
Turbodyne Technologies
http://www.turbodyne.com Developer of electricly-assisted turbos [bthomps, Oct 07 2002, last modified Oct 04 2004]
Turbodyne Complaint
http://www.wyca.com/complnts/turbo.htm Class action lawsuit against Turbodyne [5th Earth, Jun 05 2005]
[link]
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So....where does the supercharger come in? Sounds to me like the idea started out including a supercharger, but ended up just being an electrically-powered (in the first few seconds) turbo. |
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If you're going to use a supercharger at all, there's no point in using a turbo as well, unless you're going for a super-high-boost street racer engine (in which case you should probably use one or the other, not both). |
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OK, electrically powered turbocharger it is then |
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Lancia had a rally car with both supercharger and turbocharger - Lancia S4. Very complex though. |
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One thing they don't say in about that electric supercharger is the large amount of amps is pulls. When it kicked in it would put a large strain on the alternator. Thus severely shortening the life of the alternator; even if you used a high amp alternator it would still be a large strain. |
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Put a battery inline to absorb the load shock. |
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Turbodyne Technologies, Inc. (www.turbodyne.com) is working in an electricly boosted turbo for diesel and gasoline engines. The device consists of a standard turbo compressor and exhaust wheel, with a high-speed PM electric motor/generator sandwitched between them (on the same shaft as the turbo wheels). The motor would draw power from the battery (not directly from the alternator) in response to throttle input at low turbo rpm, and recharge the battery as an auxilary alternator at high-boost instead of opening a waste gate. First and second generation prototypes have been tested on both Diesel and Otto-cycle engines. One prototype installed on a conventional 2.0l gasoline engine demonstrated its ability to bring the turbo to 15psi boost at roughly 600 rpm, virtually eliminating lag. It also was able to to keep EGT near optimal during mid-range loads, demonstrating efficiency and improving the effectiveness of polution control devices. Traditional turbo chargers produce lower than optimal EGT when operating below peak load. |
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This device is not a power booster, it is a lag eliminator and has some ability to reduce emissions. Careful engine management must be observed when operating this device to prevent an undue load on the vehicle's electrical system. |
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IHI has recently contracted with Turbodyne to turn these type of electricly boosted turbos to the mass market. It remains to be seen whether the durability of the motor and the cost of the design are worth the improved throttle response of the vehicle, especially in light of other methods of managing low-end torque (such as variable cam timing and more advanced engine management computers). |
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No, I don't work for them, and I don't own stock. |
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I had the exact same idea, except that I want to bolt on a supercharger onto an already turbo-charged car. That way, we get get around the terrible low-end torque using the supercharger, but still get the incredible amount of boost from the turbocharger. The problem I see is how to "remove" the supercharger from the loop once the turbocharger gets up to speed? Otherwise, energy gets wasted when the turbo charger has to pump air through the super charger (which I suppose could be used instead of a waste gate?). |
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BTW, see my other post about the variable compression ratio engine as an alternative to the supercharger. |
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To dissengage the supercharger all that is required is that a magnetic clutch be fitted probably trigered by a boost switch. |
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WoW!! this sounds cool, although I don't even know how to open the hood on my car, I generally get it serviced a lot so the guys fill up the windscreen washer bottle as well. |
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I just posted another annotation to another thread concerning a 2 speed geared supercharger. One gear could turn the unit at 1/4 the speed of the other, thus eliminating the drag upon the engine. The idea is that you don't want the s/c to become a bottleneck in the system when it "cuts out" so to speak.I'm sure we have all seen the inside of a supercharger, and realize that if it's not turning, it sucks at flowing air. By allowing it to still run at a relatively low speed it would continue to expedite the air into the intake tract of the engine without becoming either redundant or interfering. |
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btw, electric turbo's are not superchargers, which are connected via belts to the engines, its just a turbo. |
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i have something similar, *some* superchargers have an
electro magnetic clutch and even though its not inducting
air into the engine anymore, air can still enter the engine
naturallythrough a secondary intake, could you install a
turbo charger onto the superchargers secondary air intake
untill it got to speed(it'd need a valve of some sort ot itd
blow up), and then switch off the supercharger and open
the turbo allowing it to take over for the higher rpms? |
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By the way,turbochargers are a class of supercharger. Also, DC3s had 2 speed superchargers with the higher speeds engaged at higher altitudes to help maintain sea level air pressure to the induction system. Most of the second speed, "high-blow," settings were later disabled by the aircraft owners though because of reduced engine life. |
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how else would you tell them apart then? superchargers
are an induction system that derives its power from the
crankshafy pulley, and a turbocharger derives its power
from the exhaust. without the somewhat subtle
difference there would be no need to call them
something different |
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And there isn't, really. The term "supercharger" is synonymous with "forced-induction." In the aircraft industry they're often called turbo-superchargers. Turbochargers just represent one type of supercharger. They're all kinds of different type compressors: Roots, Paxton, axial, screw, vane, Comprex pressure-wave, intersecting vane, epitrochoid, centrifugal, turbo, etc. Granted, the term "turbocharger" has distinguished itself because of its wide use. |
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i was under the impression that its name *reguardless* of
how they induct the air, came from where they got their
momentum from, but reguardless of names, my dual
induction design has a small flaw as i would require a
valve on the turbo to vent the pressure while it was
gaining momentum, and then i need it to close when the
supercharger clutch turned off, know of any valves that
would accomodate this? |
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No I don't, sorry. Maybe some sort of externally controllable waste-gate is available or could be modified? |
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my idea was a solenoid based BOV or even a BCV on the
same circuit as the electro cluth (this circuit would be a
rpm or boost based circuit but a switch would work aswell
i guess), when the electro clutch on the SC turned off
and the secondary intake opened, the solenoid would
then close that valve allowing pressure into the manifold,
a second valve (prefferably a BOV) could then take over
the other valve needs. |
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Like your idea and nice that its gonna be produced, it kinda proves it dont it!
On the other hand i dont like people bitching around with words and talking shit!
What the hell does it matters what he calls the parts, off course he can use the term turbo and supercharger even if the supercharger part is only initially!
Another thing, lets say he did a new invention guys someting very few of u can cause u would not be able to find a name for it never the less find the ground breaking thoughts to go outside the frames and come up with something new, what would he call that to satisfy u?
Next dont need much computer controle to have an electrical engine turn the turbine untill it comes up to speed, just simple electronics and a pressure sensor in the intake and an on off switch pretty much that engage at a surtain level of gas given, since it dont need to charge many psi and can switch on early to give low grunt torque.
Pretty much a tweeking that u can do to a standard turbo car in your own home garage if ure handy at all and not the kinda person that takes your car to the workshop to change sparkplugs. |
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"Turbo" magazine is running a series of articles (started in feb03 I think) on a v6 turbocharged and roots supercharged engine in a MR2. I don't have a copy but I remember some of the key points.
The first problem was the matching of a turbo to the supercharged engine to achieve the ideal power curves. Being a magazine they did not go into enough detail to explain the theory. It appears the problem is developed by the increase in the volumetric efficiency of the engine by the supercharger. If you go to the calculator section of www.turbofast.com.au you can get an idea of how the efficiency of the motor effects the turbo choice.
When intercooling the compound system the placement of the intercooler is important. Intercooler efficiency will be decreased by placing the intercooler between the turbo and the supercharger since the cooled air would be compressed again by the supercharger.
An aside in the article that I believe is very important to the performance of the engine was as the RPMs increased and the boost from the turbo became greater than the boost of the supercharger, the turbo seemed to "blow power" back into the engine. Obviously the turbo was pushing the air through the supercharger negating the parasitic drain on the crank. Based on this info there is no reason to be concerned about disengaging the supercharger as discussed in the prior posts. In fact it looks on the surface that all the focus should be on the turbo. If the turbo map is analyzed based on the volumetric efficiency of the supercharged engine, the backpressure from the supercharger is considered, and proper intercooling is utilized then a system like this should not be impractical in theory. How it will drive on the street is a different story. |
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The simplest solution I can think of to cut out the supercharger when the turbo spools up is a boost-activated CVT. You don't want the blower to be completely undriven since it will create a restriction in the intake, but there is no need in it still producing boost after exceeding it's upper range of efficiency. A CVT (Continuously Variable Transmission) would allow the supercharger to produce boost from idle all the way up to where the turbocharger gets running. As the boost pressure gets to the preset level, the blower slows to the point it just matches the airflow of the engine, providing neither boost nor significant resistance. At higher RPM's there would be no need for the blower since turbo-lag is much less noticeable at higher engine speeds. Of course, that also means the CVT could be controlled by RPM instead of boost pressure. |
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No electric motor could spin a turbo that fast, you obviously do not know much about turbonetics because turbochargers spin at very, very high RPM's somehwere around 150,000-300,000. If you can find an electric motor that will do those speeds, I will give you kudos. |
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[craigm1987] It seems as though you're assuming the impeller design would be no different than that used with exhaust gas driven turbochargers. I think an impeller designed specifically to be spun electrically would have a different form factor that allows ample boost at rotational speeds that can be achieved with an electric motor. The vane pitch might be able to be much higher, say, as the electric motor has a lot of torque. |
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Such an electric system exists, and you can buy it for 2,000 - 3,000 $ depending on the size of the engine. Instead of a Turbocharger, an Eaton M90 or M62 Roots type Supercharger is used with three 12V electric motors.For more info look: www.boosthead.com |
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I stumbled across this post, did some research, and found some disturbing information regarding Turbodyne. Basically, the company has never sold a single product, ever, does not own most of the patents it claims to hold, and has had a class action lawsuit brought against it for falsely representing itself to investors. |
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The idea sounds great on paper, I have to say that--I'd buy one if it could be bought. But the company is, frankly, a hoax, and there is no product. |
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I believe Mazda worked out a similar system on one of their rotary engine models, with an electric motor spooling up the turbo. |
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Many kinds of race cars and old airplanes use different combinations of superchargers and turbos. I once saw a diesel truck used for landspeed records with two superchargers and four turbochargers. It went pretty fast and created a huge cloud of black smoke. |
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Electric superchargers never work well. They require far too much power to be effective. |
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Electric superchargers do work, I have personally used one from www.electricchargers.com and dynoed it to prove it. Horsepower on my nsx went us 8%! |
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--- eaton superchargers are "cut out" buy opening a recirculating valve |
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