DIY_EFI Digest Thursday, September 16 1999 Volume 04 : Number 528 In this issue: Electric Superchargers Re: solid, port-able filler for intake manifold? Re: Electric Superchargers... RE: solid, port-able filler for intake manifold? Re: Electric Superchargers... Re: No one else is doing it, so there must be some obvious problem the culprit Re: DIY_EFI Digest V4 #527 See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- Date: Thu, 16 Sep 1999 05:33:44 -0700 (PDT) From: senator@xxx.edu (Bill Bradley) Subject: Electric Superchargers > Well, has anyone thought of doing this *right*? Install additional > alternator capacity to support running the unit consistently. Put in an > intercooler, etc. to support higher boost levels, like a real turbo. > > Such a system has the following advantages: > > 1) More fuel efficient than a supercharger How's that again? How is a load from the alternator any different from the load of a supercharger? > 4) No parasitic drag when not in operation; relatively little even under > boost See #1) > I can think of the following disadvantages: > > 1) Current electric superchargers may not have sufficient duty cycle > and/or airflow. > > 2) Alternator drag/battery drain may be more than I expect. Bingo! The work to compress a gas is delta-(pV). If you want a small volume (low rpm) and small increase in pressure, fine, but a 10hp electric motor would draw over 600A at 12V. Not really practical. > 4) No one else is doing it, so there must be some obvious problem that I > haven't thought of. Yep, load is load whether from a supercharger or alternator. TANSTAAFL (There ain't no such thing as a free lunch) Bill ------------------------------ Date: Thu, 16 Sep 1999 14:22:53 +0100 From: "Rich Mauruschat" Subject: Re: solid, port-able filler for intake manifold? - -----Original Message----- From: DIY_EFI Digest To: DIY_EFI-Digest@xxx.edu Date: 16 September 1999 11:03 Subject: DIY_EFI Digest V4 #527 >Date: Wed, 15 Sep 1999 23:55:35 -0400 >From: Chris Conlon >Subject: solid, port-able filler for intake manifold? > >Hi, > >For my next silly question, I'm looking for some putty or clay like >material to fill in large areas of an intake manifold. Once it hardens >I want to be able to come back with grinding tools and reshape it. Chris, Try Devcon "Titanium Putty". They recommend this for aluminium as it has a very similar coefficient of expansion over the temperature range involved. They do a range of similar stuff for different conditions; it's not cheap, but is supposed to do the job (and not fall out!). www.devcon.com (predictably enough!) good luck Rich ------------------------------ Date: Thu, 16 Sep 1999 09:51:23 -0400 From: David Cooley Subject: Re: Electric Superchargers... At 05:00 AM 9/16/1999 -0400, you wrote: >We've all (or many of us) heard/read about the "electric superchargers" >that have been marketed recently, these are devices which connect to the >intake and blow in air - but they are electric powered. They typically >run for short bursts of time to provide just a little extra grunt when >needed, and usually on naturally aspirated engines, especially diesels. The only electric unit I had heard of was from a company called Powerdyne. It isn't a supercharger, it's a motor that spins your turbo up a bit (not enough to make any measureable boost) to eliminate lag. >Well, has anyone thought of doing this *right*? Install additional >alternator capacity to support running the unit consistently. Put in an >intercooler, etc. to support higher boost levels, like a real turbo. > >Such a system has the following advantages: > >1) More fuel efficient than a supercharger > >2) Very little turbo lag > >3) Very precise and simple control of boost (electronic control system can >directly vary impeller speed to control boost) >3.5) Knock sensor system can now reduce boost as a way of preventing >detonation! Oh happy day. > >4) No parasitic drag when not in operation; relatively little even under >boost > >5) Can build boost on the line even with manual transmission, for drag >racing, or at low RPM, for road courses/autocross > >6) Easy to install. No need to fuss with the exhaust. You don't get something for nothing, and nothing is 100% efficient or greater... A typical automotive alternator is about 80% efficient at converting HP to electric power... A typical electric motor is about 80-85% efficient at converting electric power to HP. A typical blower takes 30-40 HP to make enough boost to be worthwhile... A turbo, while not as easily measured for HP drop (caused by exhaust restriction) is a bit more efficient. For an electric motor to make 30-40 HP, it would take 37,300 watts of electrical energy (at 80% efficiency) which is 2825 Amps at 13.2 volts... For an alternator to replace this, if it had the capacity, it would take 62.5 HP... The boost you make would probably give you a 30% increase in HP, so if you were 200 HP stock, your now at 260, but you're dumping 62.5 into running the boost... You've actually dropped from 200 available HP to 197.5 HP, plus the added penalty of 300-400 pounds in weight for the huge battery/alternator/motor combo. If you want efficient, economical boost, Open the exhaust and insert a turbo... It operates on demand, cruising down the highway it has no effect on mileage and it's always there when you need it. =========================================================== David Cooley N5XMT Internet: N5XMT@xxx.net Packet: N5XMT@xxx. Member #7068 We are Borg... Prepare to be assimilated! =========================================================== ------------------------------ Date: Thu, 16 Sep 1999 09:48:27 -0400 From: Dylan Johnson Subject: RE: solid, port-able filler for intake manifold? Go to http://www.fibreglast.com/FillerPage.htm look for the glass microspheres.You mix it with epoxy and it makes a nice paste that you can sand/grind fairly easily. ------------------------------ Date: Thu, 16 Sep 1999 16:05:42 +0200 From: nhoj@xxx.se Subject: Re: Electric Superchargers... You wrote: > > From the "fluffy's stupid idea files"... > > We've all (or many of us) heard/read about the "electric superchargers" > that have been marketed recently, these are devices which connect to the > intake and blow in air - but they are electric powered. They typically > run for short bursts of time to provide just a little extra grunt when > needed, and usually on naturally aspirated engines, especially diesels. > > Well, has anyone thought of doing this *right*? Install additional > alternator capacity to support running the unit consistently. Put in an > intercooler, etc. to support higher boost levels, like a real turbo. > [snip] > 4) No one else is doing it, so there must be some obvious problem that I > haven't thought of. There is kit for two-stroke motorcycles (dirt bikes, IIRC) that uses a crank mounted centrifugal compressor and one or more "secondary" electrical compressors. As I understand it, the electrical compressors are always runnging, and can be tuned to the optimum pressure. I think the centrifugal compressor doubles as an air filter, by the way... I tried to get in contact with the company to discuss its application on marine outboard engines, but never got a reply. (I have a weak spot in the power band due to rather extreme port timings.) I guess the main problem with an all out electrical system is that you're likely to need a high voltage DC generator, rather than beefing up the existing 12 Volt system. You'll also have mechanical losses from driving the generator. These losses, in addition to the electrical losses, will probably be a fair bit greater than the losses in a fully mechanical system. Therefore, I think using an electrical compressor for a secondary stage makes much more sense. Regards, John Hornkvist ------------------------------ Date: Fri, 17 Sep 1999 02:05:03 +1000 From: Phil Lamovie Subject: Re: No one else is doing it, so there must be some obvious problem Hi All, Correctomondo !!! Supercharge your average 5 litre V8 and you will need approx 30 kW or 40 hp to drive the blower. The alternator would need to be 20% bigger. say 36 kW. the alternator and electric motor would be both heavier and larger than the V8 engine they were driving. They would also have losses in the energy conversion cycle rotational to electricity and back again that would be in the order of 10%. A blower with a belt is more efficient. Phil ------------------------------ Date: Fri, 17 Sep 1999 03:55:05 +1000 From: Phil Lamovie Subject: the culprit W I R E D N E W S - - - - - - - - - - - - The Little Engine that Might by Leander Kahney Taking on the world's giant energy business, a tiny startup is set to launch an engine that requires no fuel, produces no pollution, and is free to run. Naturally, the experts think it's too good to be true -- although they can't exactly say why. Entropy Systems, a seven-person startup based in Youngstown, Ohio, is scheduled to launch the Entropy engine early next year, said the technology's inventor, Sanjay Amin, a mechanical engineer and co-founder of the company. The Entropy engine acts like a heat sponge, absorbing heat in the atmosphere and converting it to power, Amin said. Since it consumes no fossil fuels, nuclear fuels, or electrical power, it produces no emissions, directly or indirectly. Its only byproduct is cold air. Initially, the technology will be used to create an outboard motor for small pleasure boats, simply because it's the easiest market to break into, Amin said. But as it is developed, the technology could be used to run refrigerators, air conditioners, generators -- even automobiles. "There's no reason it can't power a car," Amin said. So far, Amin has built a prototype, which he said generates one-tenth of one horsepower. The outboard motor -- yet to be built -- will produce between two and three horsepower. It will be roughly the same size as a conventional outboard motor and only marginally more expensive. But, apart from routine maintenance and lubrication, the engine will be free to run. Named after the unit in physics that describes the amount of available energy in a system, the Entropy engine consists of a central chamber, filled with air, that has a piston in the center, Amin said. The engine operates on a cycle. First, a starter motor spins the engine to a high speed, which pushes the gas to the edge of the central chamber, as in a centrifuge. As the gas moves to the edge, it creates a partial vacuum in the center that draws the piston out, compressing the gas. In the second part of the cycle, the engine is slowed, and the gas redistributes itself throughout the chamber, which increases the pressure on the piston. Heat trapped in the gas is converted into the energy that moves the piston, which cools the air in the engine chamber. The engine will run year-round in any climate, even in sub-zero temperatures. Although it operates better in warmer climates, it will work in any environment above absolute zero (minus 273 degrees Celsius). "In physical terms, even ice has a lot of heat," Amin said. Amin claims to have patented the technology in the United States, Australia, and Europe. He said he has published a book on thermodynamics and in 1996 received an Engineer of the Year award from the American Society of Engineers of Indian Origin. Always obsessed with engines, Amin built steam engines as a teenager. He has devoted more than a decade to the Entropy engine. He began by looking at gravity as a power source, which eventually led to the idea of using atmospheric heat. The technology was developed in part when Amin was studying at Youngstown State University, which helped launch the fledgling company. Bill Dunn, an associate professor of mechanical engineering at the University of Illinois at Urbana-Champaign, said that while he hasn't seen the engine in action, he has examined the materials on Entropy's Web site. He said the logic appears sound, but the outcome -- free power -- doesn't make sense. "It's the end result -- that you can create power from heat at ambient temperature -- that flies in the face of the basic laws of physics," said Dunn, who acknowledges that he hasn't devoted time to figure out why the engine shouldn't work. "To track down where his thinking may be flawed is a difficult thing to do," Dunn said. In Amin's favor, Dunn noted that he has attracted backing from "some very intelligent people." Hedging his bets, Dunn said breakthrough technologies have frequently been greeted with skepticism. "Every time someone suggests something like this, you should at least give them the benefit of an open mind." Iain MacGill, an energy campaigner at Greenpeace, said that because vehicle pollution makes up about a third of US greenhouse gas emissions, a pollution-free engine would be an incredible breakthrough. Nevertheless, it sounds to him like fiction. "It's got a flavor of 'too-good-to-be-true' about it," he said. "I'm a wee bit skeptical." ------------------------------ Date: Thu, 16 Sep 1999 09:16:12 -0400 From: "Gary Derian" Subject: Re: DIY_EFI Digest V4 #527 The problem is that you needs lots of power to drive a supercharger, at least 20 hp and more than 100 hp for big power. The mechanical to electric to mechanical conversion is not so efficient. A 20 hp alternator and 20 hp electric motor are really big and heavy and expensive. A belt drive is way better. Heck, you can't even get an electric radiator fan to cool well under severe conditions. Gary Derian > > Well, has anyone thought of doing this *right*? Install additional > alternator capacity to support running the unit consistently. Put in an > intercooler, etc. to support higher boost levels, like a real turbo. > ------------------------------ End of DIY_EFI Digest V4 #528 ***************************** To subscribe to DIY_EFI-Digest, send the command: subscribe diy_efi-digest in the body of a message to "Majordomo@xxx. 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