IDEA!!! Electric air compressor as turbo? YES? NAY?

japanesecowboy14 · Post by **japanesecowboy14** » Mon Jan 05, 2009 12:25 am

http://www.amazon.com/dp/B000RNWHLA?smi ... nkCode=asn

So i recently ran into this little item @ Harbor freight today, and I thought it would be funny to have these little squeakers as a horn. Once I got into it & realized that it uses a direct drive compressor at 15psi, WHAT IF you could use the air outlet to pipe into your intake? mind you, the smaller the pipe or duct, the more pressure, so if it's rated at 15psi with a 1/2 inch duct (air outlet), it would probably rate towards about 6 or 7 psi when installed in a 3" intake. Thoughts? Suggestions?

I know with some of the crazy modders i'm sure someone who got an idea to use a portable air compressor or a shopvac of some sort.

skid542 · Post by **skid542** » Mon Jan 05, 2009 1:08 am

I hate to burst the bubble, but this simply not going to work.

It's rated at 15 psi, it will create 15 psi in any pipe size you want, just not very fast. Our motors are typically 2.2L, so if you're at 5000 rpm that means you are pushing roughly 11,000 liters of air per minute or roughly 183 liters of air per second.

Pretty sure Harbor freight doesn't have any compressors that can handle that type of flow....

It's a nice thought, but just not really feasible.

ScottyS · Post by **ScottyS** » Mon Jan 05, 2009 1:38 am

My private plan for ghetto boost is to add an adapter for canned air from Office Depot.

And a big red button on the steering wheel.

93forestpearl · Post by **93forestpearl** » Mon Jan 05, 2009 3:07 am

A four-stroke engine does not consume it's displacement every crankshaft rotation.

My turbo will support about 700-750cfm (48 lb/min by garrett standards). That little thing can in no way move enough air to feed a 2.2L engine, let alone create positive manifold pressure. Maybe if you had 100 of them plumbed in parallel, but the current requirement would make it not feasible for a normal charging system.

SLODRIVE · Post by **SLODRIVE** » Mon Jan 05, 2009 3:26 am

No way would that actually work. The amount of airflow it would take to pressurize an automotive intake (that already has air moving through it) is far, far beyond its capabilities.

Expanding on what skid542 posted...Assuming the motor is at 100% volumetric efficiency, at 5000 rpm's it actually needs 5500 liters/minute of air (2 revs = 1 cycle in a 4-stoke engine), which equals about 194 cfm, which still doesn't account for the fact that turbocharged engines operate at well over 100% VE, which would require even more air...see where this is going?

By the time you managed to get any electric pump to flow that much air, it would create a huge parasitic drag on the alternator and/or overheat the intake charge to where an intercooler would be needed. At that point, any advantage at all over a conventional turbo- or super-charger suddenly disappears. Ebay's full of electric superchargers, but oddly I have yet to see one at the dragstrip or on dyno day, lol.

Besides, even if that compressor was capable of producing any amount of pressure in the motor, it would be totally unregulated in relation to load, throttle position, RPMs, etc...scary at best!

I'm not trying to burst your bubble either, but this kind of thing has been proven ineffective too many times, in too many ways. That said, I'd love to see someone prove everybody wrong...Just be aware of what you're up against.

ScottyS · Post by **ScottyS** » Mon Jan 05, 2009 3:45 am

Can't help myself:

skid542 · Post by **skid542** » Mon Jan 05, 2009 5:43 am

Thanks Dan, I get ahead of myself sometimes....

93forestpearl · Post by **93forestpearl** » Mon Jan 05, 2009 5:56 am

No worries. I've put my foot(s) in my mouth plenty of times.

japanesecowboy14 · Post by **japanesecowboy14** » Mon Jan 05, 2009 2:15 pm

Very scientific DYNO sheet you provided there... ROTFL.... I just figured it would make a nice idea to babble over, but I also reailzed if it were that simple, alot of turbo companies would be pissed and broke.. I had the same idea for a portable 5hp shopvac, (reverse the hose) but that would require AT LEAST a 50 amp inverter. For now, i guess i'll just route a hose from the TBI through the firewall, and blow through it really hard when I need more passing power

kimokalihi · Post by **kimokalihi** » Mon Jan 05, 2009 3:57 pm

Quite sure all that's gonna happen if you blow in it is it's going to suck far more air than you can blow and you'll end up getting the air sucked right out of your lungs haha! Especially when you hit the accelerator. You may even collapse a lung. Wouldn't do that if I were you.

evolutionmovement · Post by **evolutionmovement** » Mon Jan 05, 2009 6:44 pm

You could use a compressed air tank and a large pipe to dump air into the intake, but it would only be good for short periods (like for use as an antilag system) and would have to be recharged (which a combination of excess boost bled through some kind of valving plus the excess from the blow off valve could do on-board, however, that may also put some vaporized fuel into the system). Plumbing would be pretty complicated as well, since the tank would be about trunk-sized and the pipe would have to go through the cabin and firewall. It has been done, but I'm not sure how far the WRC teams (Ford and Subaru) went with the on-board recharging nor its efficacy (though the FIA's quick banning of the system indicates that it probably worked). The blow-off valve would be easy, but not give lots of volume, while running excess boost and diverting it would be more complicated. Or you could just stop off at a gas station air compressor (if that would even give enough pressure). You also wouldn't want that sucker, fully charged, to be punctured in a collision. Then again, it might even be better to just use the system to dump into the up pipe to keep/get the compressor spinning as volume wouldn't be as much of a factor (then what would the cold air do in the hot exhaust?). No matter what, this wouldn't work with an N/A car.

japanesecowboy14 · Post by **japanesecowboy14** » Mon Jan 05, 2009 9:26 pm

kimokalihi wrote:Quite sure all that's gonna happen if you blow in it is it's going to suck far more air than you can blow and you'll end up getting the air sucked right out of your lungs haha! Especially when you hit the accelerator. You may even collapse a lung. Wouldn't do that if I were you.

Especially being such an environmentally friendly weezing chainsmoker myself... HEY --- it's better than saying i'm a second-hand smoker!

kimokalihi · Post by **kimokalihi** » Tue Jan 06, 2009 3:23 pm

japanesecowboy14 wrote:
kimokalihi wrote:Quite sure all that's gonna happen if you blow in it is it's going to suck far more air than you can blow and you'll end up getting the air sucked right out of your lungs haha! Especially when you hit the accelerator. You may even collapse a lung. Wouldn't do that if I were you.
Especially being such an environmentally friendly weezing chainsmoker myself... HEY --- it's better than saying i'm a second-hand smoker!

I work at a casino that happens to be owned by indians. Which means they can smoke all they want indoors. Which also means everyone who smokes comes there because it's one of the very few places in the state they can smoke while wasting their life away gambling and drinking. I get my fair share of second hand smoke and then some and I still come back for some more the next day. It's bullshit. I know I'm gonna get cancer one of these days. I choose to work there and everything but still I don't think the indians should be able to do anything anybody else can't do. They get it way too easy.

Back on topic....

Wouldn't the weight of a massive O2 tank in your trunk kind of cancel out the minor gains you'd get from it?

Buffman · Post by **Buffman** » Tue Jan 06, 2009 3:36 pm

kind of like the electric supercharger that actually works. You need a lot of batteries to power it. Yes there is really an electric supercharger that works, not some POS you find on ebay.

http://www.turbomagazine.com/tech/0406t ... index.html

japanesecowboy14 · Post by **japanesecowboy14** » Tue Jan 06, 2009 4:16 pm

It's not a tank.. it's a direct drive compressor, about the size of a pop can, really (they make bigger ones for bigger rigs)... brilliant supercharger design.. (unlike the computer fan in your CAI layout on ebay) looks like the initial drive uses about 5 different gears simutaneously to crank the turbine around alot faster than the initial motor rotation..
.
p.s. if i find the link again, that has cutout pics and everything i'll post also... this thing is a TRIP almost a 1 to 10 drive ratio

SLODRIVE · Post by **SLODRIVE** » Tue Jan 06, 2009 6:17 pm

Buffman wrote:kind of like the electric supercharger that actually works. You need a lot of batteries to power it. Yes there is really an electric supercharger that works, not some POS you find on ebay.

http://www.turbomagazine.com/tech/0406t ... index.html

LOL...IDK if I'd actually say that thing works. According to the article, you need FOUR Optima batteries just to power the thing...nothing like adding 200-300 lbs. of weight to make a car faster. Also, I noticed that there's zero boost control, and besides, the output is only going to go downhill as the batteries discharge.

I'd have to say that a NOS setup makes a lot more sense than a blower that needs a battery charger, eh?

Buffman · Post by **Buffman** » Tue Jan 06, 2009 8:02 pm

that's why i stated you need a lot of batteries to keep it going. agreed better off with juice.

evolutionmovement · Post by **evolutionmovement** » Tue Jan 06, 2009 9:11 pm

Or a turbine that is spun off wasted energy in exhaust gas.

Post by **Legacy777** » Tue Jan 06, 2009 9:19 pm

Imagine that

One thing I thought that is worth noting is that in their "pros" section the article talks about turbos, and the info they have is grossly incorrect, especially when talking about pressure being the main driver, and exhaust to intake pressure ratio.....never heard of such thing. I've heard of pressure ratio, but that relates to what the pressure across the compressor.

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IDEA!!! Electric air compressor as turbo? YES? NAY?

IDEA!!! Electric air compressor as turbo? YES? NAY?