Electric Supercharger Offers Diesel Efficiency For Gasoline Engines
09-22-2009, 03:20 PM
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Electric Supercharger Offers Diesel Efficiency For Gasoline Engines
Existing hybrid technology uses electrical energy stored in a battery to power an electric motor connected to an internal combustion engine, but there are other ways of harnessing electrical energy to help save fuel. Engineers in the UK have developed a new system where electrical energy can be used to drive a supercharger and boost performance.
Conventional superchargers are powered by a belt connected to an engine. As more power is dialed up, the supercharger draws more and more power away from the engine and in turn burns more fuel.
Last year, British firm Controlled Power Technologies (CPT) revealed an electric supercharging system developed for small fuel-efficient engines that does away with the belt system. Dubbed the Variable Torque Enhancement System (VTES), the system is ready for mass production and can be applied to all types of gasoline and diesel engines--including those already turbocharged.
CPT recently teamed up with German powertrain developer AVL List GmbH (AVL) and together the companies have unveiled a gasoline engine with the same CO2 emissions as a similarly powered diesel. The particular engine was a 2.0-liter four-cylinder gasoline unit with direct-injection technology and 197 horsepower and 295 pound-feet of torque available. When fitted in a Volkswagen Passat, the electrically-supercharged engine produces CO2 emissions of 159g/km. The regular 167 horsepower 2.0-liter TDI diesel Passat on the other hand emits 165g/km, while the 197 horsepower 2.0-liter TFSI gasoline version emits 194g/km.
CPT has also signed a deal with Switched Reluctance Drives Limited to start developing OEM units for sale later this year but so far no automakers have announced plans to use the electric supercharger.
The fully developed and production-ready device could prove timely in helping automakers meet governmental directives to cut average CO2 emissions and fuel economy levels for new cars in coming years.
Conventional superchargers are powered by a belt connected to an engine. As more power is dialed up, the supercharger draws more and more power away from the engine and in turn burns more fuel.
Last year, British firm Controlled Power Technologies (CPT) revealed an electric supercharging system developed for small fuel-efficient engines that does away with the belt system. Dubbed the Variable Torque Enhancement System (VTES), the system is ready for mass production and can be applied to all types of gasoline and diesel engines--including those already turbocharged.
CPT recently teamed up with German powertrain developer AVL List GmbH (AVL) and together the companies have unveiled a gasoline engine with the same CO2 emissions as a similarly powered diesel. The particular engine was a 2.0-liter four-cylinder gasoline unit with direct-injection technology and 197 horsepower and 295 pound-feet of torque available. When fitted in a Volkswagen Passat, the electrically-supercharged engine produces CO2 emissions of 159g/km. The regular 167 horsepower 2.0-liter TDI diesel Passat on the other hand emits 165g/km, while the 197 horsepower 2.0-liter TFSI gasoline version emits 194g/km.
CPT has also signed a deal with Switched Reluctance Drives Limited to start developing OEM units for sale later this year but so far no automakers have announced plans to use the electric supercharger.
The fully developed and production-ready device could prove timely in helping automakers meet governmental directives to cut average CO2 emissions and fuel economy levels for new cars in coming years.
09-22-2009, 03:33 PM
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Anyone know how this compares to the LNF for CO2 emissions? I am thinking that the electrical draw from the alternator would be a problem with more accessories turning into electrically driven as opposed to belt driven.
09-22-2009, 05:21 PM
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Saw the link earlier today on jalopnik and didn't think to post it.
http://jalopnik.com/5365041/electric...ve-other-ideas
Interesting to say the least...
http://jalopnik.com/5365041/electric...ve-other-ideas
Interesting to say the least...
09-22-2009, 07:42 PM
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If combined with regenerative braking and additional batteries, only then can I see a real benefit to this.
The problem is the electricity used to spin this thing is created by burning gasoline to drive the alternator. If you used a fully charged battery (or multiple batteries) during a test run it'll indeed lower emissions and seem amazing - but over the long term it won't help. I quick looked at it - over 200A partial load, nearly 350A max current.
And their numbers are crap. Comparing the c02 levels from a gasoline to a diesel is not an apples-to-apples comparison. They also do not point out the fact that while the electric unit may give torque, it isnt always available to the driver like a real turbo or supercharger is. Lame. I'd bet huge money they didnt fit the VW with a 200A alternator - which *still* wouldnt provide enough oomph to run the unit all the time. Also, that giant alternator would have killed their c02 numbers and likely made them *far* worse. Bosch makes a great 200A alternator - but it takes a lot of power under load.
And that doesn't even go into the increased wear & tear on your battery and charging system - which would be pronounced.
And then if you romped on a car with one of these really hard and it didn't have an interlock to stop it at a certain battery level, you could turn the car off, go into a gas station, and come back to a car without enough juice to start. People in cold climates would get hit twice as bad.
and FWIW,
the 2L DI (non turbo) GM engine is rated at 149g/km
the LNF is rated at like ~221g/km (more c02 but more hp)
and the VXR8 (G8 with LS3 woot!) is rated at 364g/km with a stick or 345 with an auto.
Also, Mercedes and many other companies have looked into taking a variable geometry turbocharger and adding an electric motor to be able to pre-spool it to push things to the next level (and do what these guys have done) - but in the end systems were developed and tested -- and then shelved. These systems were even shelved for the trucking industry - where having 4 giant batteries with a sum of 2800CCA is common.
The problem is the electricity used to spin this thing is created by burning gasoline to drive the alternator. If you used a fully charged battery (or multiple batteries) during a test run it'll indeed lower emissions and seem amazing - but over the long term it won't help. I quick looked at it - over 200A partial load, nearly 350A max current.
And their numbers are crap. Comparing the c02 levels from a gasoline to a diesel is not an apples-to-apples comparison. They also do not point out the fact that while the electric unit may give torque, it isnt always available to the driver like a real turbo or supercharger is. Lame. I'd bet huge money they didnt fit the VW with a 200A alternator - which *still* wouldnt provide enough oomph to run the unit all the time. Also, that giant alternator would have killed their c02 numbers and likely made them *far* worse. Bosch makes a great 200A alternator - but it takes a lot of power under load.
And that doesn't even go into the increased wear & tear on your battery and charging system - which would be pronounced.
And then if you romped on a car with one of these really hard and it didn't have an interlock to stop it at a certain battery level, you could turn the car off, go into a gas station, and come back to a car without enough juice to start. People in cold climates would get hit twice as bad.
and FWIW,
the 2L DI (non turbo) GM engine is rated at 149g/km
the LNF is rated at like ~221g/km (more c02 but more hp)
and the VXR8 (G8 with LS3 woot!) is rated at 364g/km with a stick or 345 with an auto.
Also, Mercedes and many other companies have looked into taking a variable geometry turbocharger and adding an electric motor to be able to pre-spool it to push things to the next level (and do what these guys have done) - but in the end systems were developed and tested -- and then shelved. These systems were even shelved for the trucking industry - where having 4 giant batteries with a sum of 2800CCA is common.
Last edited by Geoff Chadwick; 09-22-2009 at 07:45 PM.
09-23-2009, 11:25 AM
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To build on what Geoff said, ideally they'd employ a second set of batteries whose sole purpose is to drive the supercharger. This would prevent the rundown condition of the main battery, and also allow them to easily wire them in series to up the voltage and reduce the amperage (the wiring alone to carry 350A would be huge and heavy). There would also likely be a switch to cut out the alternator when under boost so as to not rob all the extra power being created, and also give the car a chance to charge the batteries with regen instead.
Another problem with such systems is that they don't scale up very well. If you need 350A @ 12 volts (over 5 horsepower) to run the supercharger on a 2.0L four-banger, you can triple that for a 6.0L V8 ... now you're into major issues with size, heat, weight, and packaging when you need to get 1000A to a 15-20 horsepower electric supercharger.
Another problem with such systems is that they don't scale up very well. If you need 350A @ 12 volts (over 5 horsepower) to run the supercharger on a 2.0L four-banger, you can triple that for a 6.0L V8 ... now you're into major issues with size, heat, weight, and packaging when you need to get 1000A to a 15-20 horsepower electric supercharger.
09-23-2009, 06:32 PM
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Particulates cause lung cancer, which is a pretty nasty way to go.
NOx causes smog, which is just nasty.
Cleaning these up in a diesel is expensive.
09-23-2009, 08:56 PM
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2010 diesel emissions are pretty impressive. The problem is the emissions equipment is so costly now it adds another few grand to the vehicle (or more). Not to mention try telling your average american they need a separate 'fuel' tank for 'diesel emissions fluid'. that won't go over well. The fluid also freezes easily, so the fluid lines need to have a purge system added to them to empty them of fluid. The tank also needs a heater to keep it from freezing. The particulate filter either needs to be replaced (cheap filter) or go through a periodic regen cycle (which requires an expensive re-usable filter) to burn up the particulates.
And now the government is mandating c02 emissions along with CAFE, so diesels are going to become even less common in cars.
And now the government is mandating c02 emissions along with CAFE, so diesels are going to become even less common in cars.
09-23-2009, 09:11 PM
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2010 diesel emissions are pretty impressive. The problem is the emissions equipment is so costly now it adds another few grand to the vehicle (or more). Not to mention try telling your average american they need a separate 'fuel' tank for 'diesel emissions fluid'. that won't go over well. The fluid also freezes easily, so the fluid lines need to have a purge system added to them to empty them of fluid. The tank also needs a heater to keep it from freezing. The particulate filter either needs to be replaced (cheap filter) or go through a periodic regen cycle (which requires an expensive re-usable filter) to burn up the particulates.
And now the government is mandating c02 emissions along with CAFE, so diesels are going to become even less common in cars.
And now the government is mandating c02 emissions along with CAFE, so diesels are going to become even less common in cars.
Frankly, given the supply issues for diesel fuel in the U.S., I don't know that we really want cars to use diesel. It'd probably drive up the cost significantly until refineries could be rebuilt.
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