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Chris Cristini

Tue Mar 17 2009, 06:28AM

Registered Member #1749 Joined: Fri Oct 10 2008, 02:04AM
Location: Claremont New Hampshire
Posts: 497

I was planning on building a electronic turbo using a 24V 300W motor with a 10 to 1 ratio gear box. I figured that the motor would have to turn at 12.000RPM to get around 115.000 to 120.000RPM. And from what I understand the compressor wheel in a TD04 turbo has to rotate at about 95.000RPM to produce 12LBS of boost. I might just need a bigger motor because I read a thread in some other Forum that the turbo's compressor wheel needs a lot of power to rotate at those speeds. I just want to prove that it can be done and be more efficient than any other type of aspiration and cheaper because u would not need an expensive inter cooler and use less tubing. And I think it would look kinda cool under the hood.

Bjørn

Tue Mar 17 2009, 08:13AM

Registered Member #27 Joined: Fri Feb 03 2006, 02:20AM
Location: Hyperborea
Posts: 2058

I am not going to say that an electric turbo is impossible but your numbers does not add up at all.

You are going to need as much air as a good vacuum cleaner can privide, at many times the pressure. That means many times the power, since a vacuum cleaner is in the 1000-2000 W range you need a lot more. Possibly up to 10% of the engine output.

300 W is not going to do much useful, to get a good pressure at usable engine RPM you are going to need several kW at least.

You don't mention want you expect the result to be. If you want to replace a normal exhaust driven turbo you need to scale up your project by at least 2000 %.

Steve Conner

Tue Mar 17 2009, 12:50PM

Registered Member #30 Joined: Fri Feb 03 2006, 10:52AM
Location: Glasgow, Scotland
Posts: 6706

+1 on all that. Also, the advantage of a turbo is that it makes use of energy in the exhaust gases that would otherwise be wasted. To be sure, some of the power driving the turbine comes from back pressure, but some of it also comes from the heat in the gases. It's almost like a hybrid between a piston engine and a jet.

That's as opposed to a supercharger, where the power to compress the intake air has to come from the engine crankshaft. And it can be a lot of power. The only statistic I know is that the supercharger on a Top Fuel dragster uses about 400hp.

A really interesting project would be a turbo with both a turbine and a brushless motor/generator. It might get rid of turbo lag (the engine computer could spool it up electrically as soon as you put your foot down) and eliminate the need for wastegates, blow-off valves, variable geometry, and so on, maybe even get rid of your alternator.

Chris Cristini

Tue Mar 17 2009, 01:38PM

Registered Member #1749 Joined: Fri Oct 10 2008, 02:04AM
Location: Claremont New Hampshire
Posts: 497

I can't seem to find 12 or 24V 1000W motors but I found one with a controller but it is 36V mayby I will have to find an old electric lawn mower I know they have fairly large motors.If I am successful like steve mentioned using the brain to spool the turbo up or down and completely eliminate the need for waste gates and BOV's. It would cost less than half a turbo kit but also if it is going to produce more than 7LBS of boost u would still have to upgrade gaskets and fuel injectors on a stock engine from what I understand.

Nik

Tue Mar 17 2009, 08:59PM

Registered Member #53 Joined: Thu Feb 09 2006, 04:31AM
Location: Ontario, Canada
Posts: 638

You have to be very careful as to what type of "fan" you use for your compressor, a regular fan or vacuum cleaner blower do not build up pressure when you block off the output they reach some static low pressure and stay there. Your best bet would be to get a centrifugal super charger, which is a centrifugal compressor (turbo style compressor) that is run from a belt off the engine.

Your best bet for a motor would be a cordless angle grinder (bold in case you don't read any other part of my post). They run at the right speed (13Krpm range) and they are the right voltage (keep in mind that you usually get 14-16 volts from a cars electrical system so a 14.4v grinder will work). You might want to look into controlling the amount of boost you get at different engine RPMs, having the boost on all the time will muck with your idle.

Arcstarter

Tue Mar 17 2009, 10:11PM

Registered Member #1225 Joined: Sat Jan 12 2008, 01:24AM
Location: Beaumont, Texas, USA
Posts: 2253

I am a bit confused now. If it is indeed a turbocharger, it uses the pressure straight from the exhaust manifold to spin the output turbine, by spinning the first turbine. A supercharger is what uses rotation from an engine, but it is more parasitic. You guys are talking about needing motors, so it sounds like you are talking about super 0.o.

But why use electrical power, when that will still load the alternator and still be parasitic? Use the rotation the engine already produces and save some life on your alternator. Either that or turbo, but those are more expensive.

Am i completely missing something right now?

Chris Cristini

Tue Mar 17 2009, 11:31PM

Registered Member #1749 Joined: Fri Oct 10 2008, 02:04AM
Location: Claremont New Hampshire
Posts: 497

I was going to use a compressor wheel with the housing and core from the TD04 I have already done this sort of thing but it was directly connected with a drill motor and did not rotate fast enough to really do anything except shoot a soda can throu a tube. So I thought I would be more creative so I was just asking your guy's opinion.

Arcstarter

Wed Mar 18 2009, 03:05AM

Registered Member #1225 Joined: Sat Jan 12 2008, 01:24AM
Location: Beaumont, Texas, USA
Posts: 2253

Oh i totally forgot. If you have a welder or other equipment, you can perhaps use a vacuum cleaner motor? If you want it to run on batteries, make a simple converter or use a prebuilt one.

Is this going to actually be blowing into the carburetor/fuel injector BTW?

Renesis

Wed Mar 18 2009, 06:50PM

Registered Member #2028 Joined: Mon Mar 16 2009, 08:13PM
Location: Norway
Posts: 319

First of all, a turbocharger that is not driven by a turbine is called a super-charger, and they have been around for some years...

The main big genious idea of a turbocharger is to make use of the energy that is normally wasted in the exhaust. That, plus the cost, is what made them so much more popular than supercharger. In fact, the swedish truck producer Volvo has been experimenting with turbine driven alternators to make further use of the energy wasted on the exhaust.

If mounting a super-charger increases your engines power by 30hp, about 15-20 of those will be needed to drive the supercharger. Total power gain would be 10-15 hp. A turbocharger of the same size wouldnt steal more than 5 hp, probably less.

You say an electric turbo would not need an intercooler, that is not true. The high air temperature does not mainly come from the exhaust, but the compression.

An electric system would also have a lot more energy loss, as the enegy is transferred many times. Mechanical - electrical - and back to mechanical again. Just think about all the heat produced by the alternator and the motor, it is pure loss.

As BjÃ¸rn said the motor driving this must be very powerful. A 2kW vacum cleaner does deliver roughly the same amount of air, but at a lower pressure. So you need more than 2kW, i would estimate around 5kW. To put things in perspective, the starter motor of a 100hp tractor is roughly 1,0-1,5kW. In other words you need a BIG ASS mothafucin' alternator!

Look at what it says: 100HP! Although i dont really believe it is true, 100hp should pin him to the wall.

Electric turbochargers like those you describe do already exhist, and they are what is known as atmosferic turbochargers. As the name describes they dont actually produce much of a pressure, they just help the engine suck in air. Ebay is flowing over with these. Crappy plastic fans.

Steve, what a brilliant idea! A turbo/turbine generator hybrid would give you a total control of the turbo charger, and with an over-sized turbine wheel the exess power could eliminate the need for alternators. Why havent anyone thought of that before? Fantastic.

Chris Cristini

Thu Jul 09 2009, 03:18PM

Registered Member #1749 Joined: Fri Oct 10 2008, 02:04AM
Location: Claremont New Hampshire
Posts: 497

Hear is a small update I under stand that what I am trying to do is not a turbo but a supercharger and if I could some how make a motor like this

,000%2Brpm%26hl%3Den%26safe%3Doff%26sa%3DG%26um% 3D1 and this

it would come together and I understand that it would not be verry efficient and if atmospheric pressures at sea level are 14PSI it would have to produce 21PSI to get 7 pounds of boost all in all it would be a pain to build and test.

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