Electric forced air induction?

[nissanfanatic]

^Exactly. I have tested it with a shop-vac. I fitted a pressure gauge on it and closed off the end of the hose. It was close to 1psi of pressure. And this shop vac rated the speed of the blower at 170mph. So no it won't work.

And Saabjohan, I think he was joking.

All engines operate under a vacuum until the throttle blade is opened enough. On a NA engine that is. Do you honestly think you discovered a breakthrough in FI technology? I mean, I guess I shouldn't have spent $2500 on my turbocharger setup. And all the professional car builders should just go on Ebay sometime.

[J-Ri]

Well, maybe I shouldn't have thanked Twitch1 for his smart-ass comment, just keep getting more.

[astroracer]

Originally Posted by J-Ri

Well, maybe I shouldn't have thanked Twitch1 for his smart-ass comment, just keep getting more.

The reason you keep getting smart ass comments is because you aren't listening... THESE THINGS DON"T WORK!!!! (was I yelling?) Sorry...
This... http://www.electricsupercharger.com/ is the ONLY "legitimate" electric supercharger I know of...
Go to the site... Read their ad. Do you see where it says their unit MAY provide a 4 to 6% increase on motors up to 5.0 Litres? 5.0 Litres is around 300 Cubic Inches. Your "350" is bigger then that. Your 350 is may be putting out 190 HP. 6% of 190 is 11.4 HP which you MAY see but, more then likely won't, because your motor is too big for the supercharger and all it will do is restrict airflow.
This is all stuff I've learned by first hand experience, searching and reseaching on my own. I will recommend you do the same. If you have a problem with the answers you are getting then do the damn research yourself. (Now that I've done it all for you...)

[MagicRat]

Originally Posted by SaabJohan

A leaf blower is as the name implies, a blower, a blower doesn't compress the air. To get a power increase the air must be compressed (no ifs and buts), to compress the air the blower must feed air in a rate greater than the engine can consume. This will result in an increased pressure and and then a state of equilibrium where the mass flow over the compressor is equal with that over the engine. The problem with the leaf blower (those fitted with high power output gasoline engines) is that its blower isn't designed to increase pressure, it's just intended to increase airspeed and increasing the pressure does not only require quite some power, it also needs a carefully designed compressor.

12 volts and 12 amps is equal to 144 watts... I have more power than that in my electric R/C car.

I will however not say that it's totally impossible to get more power using leaf blowers. There are poeple that have build their own flow benchs using vacuum cleaner motors and fans, these only test on one cylinder and the pressure achieved with the fans are very low... still you need perhaps 10 motors to get the performance you need. So for a leaf blower to work you will need say 10 of those in a series increasing the pressure little by little while maintaing their flow. If you do that, then you probably can increase the power just a little on a small engine.

Saab, I was joking. But thank you for your in - depth reply.
All these leaf blowers provide excellent flow, but when the column of air slows down past a certain point the impellers tend to cavitate and pressure falls, which, of course is the opposite effect than a real compressor. As you say, this is a function of the impeller design.

The old style GM turbos (60's Corvair and Jetfire) as well as the old McCollough centrifugal superchargers functioned at about 5 psi - which would be a reasonable goal for my project. I do intend to work with this concept and post any relevant results.

Yes, 12 amp at 12 volts is not much power. Still the concept of an electric compressor has some merit in certain applications.

[gmatov]

Just because I was there, I looked at the "leaf blowers" at Sears.

400 CFM, average.

Ridiculous to think of putting a 2 cycle gas powered blower in line, BUT, any forced feed of air, regardless of the pressure, WILL give you an advantage.

If you are drawing 21 inches of vacuum, at 5000 RPM, and dying, feeding the intake 400 CFM, at a "1 pound" max, as above, gives you, still, 400 CFM of air that you didn't have.

That 350 draws 506+ cfm at 5000 RPM.

How, pray tell, can forcing even 1 additional pound of pressure not help, at 400 CFM? The reason that a turbo has 1.4 BAR of boost is to make up for the starvation when the engine is trying to suck more air than the intake will allow to pass, as the damned thing is a slave of inertia.

And, no, that leaf blower, or that shop vac, is not just a "fan", it actually does create a vacuum, and it will actually put out a pressure. When you shut off the intake of a vac, it does not whine in "agony", it howls with glee, as there is no air for it to move, so the impellor is freewheeling, totally unloaded.

This is entirely for argument, as I don't intend to attach a leaf blower to my Audi. However, I must admit, my 85 5000 Turbo had much more balls than my 90 100.

Cheers,

George

I'm sorry,I ignored SaabJohn's post.

An airpump can be either a simple air pump, or a vacuum pump, or a compressor. Depends on what you are doing with it.

You can have a propellor, or an impellor, or a vane type air mover.

All will make pressure, though to varying degrees. You might think ONLY a turbo design can move air as you need it. All other designs are useless. Nikola Tesla, around the turn of the 20th century designed a turbine that had absolutely smooth sides, no vanes, fins, nothing.

[astroracer]

Originally Posted by gmatov

Just because I was there, I looked at the "leaf blowers" at Sears.

400 CFM, average.

Ridiculous to think of putting a 2 cycle gas powered blower in line, BUT, any forced feed of air, regardless of the pressure, WILL give you an advantage.

If you are drawing 21 inches of vacuum, at 5000 RPM, and dying, feeding the intake 400 CFM, at a "1 pound" max, as above, gives you, still, 400 CFM of air that you didn't have.

That 350 draws 506+ cfm at 5000 RPM.

How, pray tell, can forcing even 1 additional pound of pressure not help, at 400 CFM? The reason that a turbo has 1.4 BAR of boost is to make up for the starvation when the engine is trying to suck more air than the intake will allow to pass, as the damned thing is a slave of inertia.

And, no, that leaf blower, or that shop vac, is not just a "fan", it actually does create a vacuum, and it will actually put out a pressure. When you shut off the intake of a vac, it does not whine in "agony", it howls with glee, as there is no air for it to move, so the impellor is freewheeling, totally unloaded.

This is entirely for argument, as I don't intend to attach a leaf blower to my Audi. However, I must admit, my 85 5000 Turbo had much more balls than my 90 100.

Cheers,

George

I'm sorry,I ignored SaabJohn's post.

An airpump can be either a simple air pump, or a vacuum pump, or a compressor. Depends on what you are doing with it.

You can have a propellor, or an impellor, or a vane type air mover.

All will make pressure, though to varying degrees. You might think ONLY a turbo design can move air as you need it. All other designs are useless. Nikola Tesla, around the turn of the 19th century designed a turbine that had absolutely smooth sides, no vanes, fins, nothing.

Okay, for arguments sake, lets use your numbers as an example...
You say that the leaf blower puts out 400 cfm average. This will be at full speed with NO restriction at the outlet. What does it put out when you hook it up to an air intake? You can't tell us that because there are no numbers to back it up. The leaf blower is not designed to "work" with a restriction. It cannot compress the charge therefore output will go down because it can't flow freely.
You also say that a 350 draws 506 cfm at 5000 RPM. Think about this for a minute. If your leaf blower only puts out 400 CFM how is it going to supply 506CFM to a 350 motor running at 5000 RPM? In order for this "blower" to work as you describe, it will need to be running in a sealed system that allows NO outside air flow. How many CFM will the motor actually be getting? I guarantee it will be a lot less then it really needs to run efficiently.
There is nothing to substantiate that ANY of these fans will "improve" performance in an automotive application and any real testing has proven them to be only a restriction that hurts performance.
Mark

[Hypsi87]

OK like I posted in the other eletric turbocharger thread.


ok peeps


A turbocharger DOES NOT INCREASE AIR FLOW BY BLOWING MORE AIR INTO YOUR SYSTEM. A turbocharger compresses the air charge and then feeds it to you engine. It's like taking all the air that is in the room your in right now and putting it into a beer bottle. Still the same ammount of air..... Just more compressed, Which means you have a more dense air charge.


Like this.




Now a "eletric supercharger just twirls around and does nothing.



In fact I garuntee that when you went WOT your engine would pump enough air to Drive the fan.

I feel visual learning is the most effectiveway to communicate

[gmatov]

Astroracer,

One thing you have to realize, at 5000 RPM,that engine theoretically draws 500 CFM.

But it won't draw a full charge at high revs. Air has inertia. It's one of the reasons they developed turbos and superchargers.

Also why an engine develops max torque and max HP at less than max RPM. It's running out of air.

So, any extra air you can force into the throttle body, the better the performance.

I'm not condoning this entire idea, just saying that most anything except that heating duct fan in the picture will put more air there than you will get without, as long as it doesn't, at the same time, cause an obstruction.

Anytime you move air, even by waving your hand, you ARE compressing air. You are trying to force it into the space your hand is waving toward, but there is no restriction there so those molecules move so the pressure goes back to equilibrium, atmospheric pressure.

I just went to the garage and put a gauge, just held in the web of my thumb, over the shop vac outlet hose, not a tight seal. It also has a not new filter, so some restriction to flow.

It puts out 18 ounces, 32 inches H2O, 8 kilopascal. So, you see, it actually does compress air.

A turbocharger, with no restriction, such as an intake manifold, would also move a lot of air with not a very high rise in pressure. When you use it in a car, depending on the throttle position, you might get up to, what, 2 BAR?

You get the engine to 6000 RPM or more, you might be sucking more air than even the turbo can supply, the engine poops out.

Have to go back to the engineering site, check this stuff out. No idea of the volume an Audi turbo has.

Gotta go , now, but this is interesting.

Cheers,

George

[nissanfanatic]

Just because the leaf blower can flow 400cfm doesn't mean its gonna. All it will do is back up into the blower and the blower will discontinue flowing air. Put your hand over the end of one of those blowers. What happens? Air just stops coming out.

Put your hand over the end of the turbocharger. What happens? Your hand doesn't stay on it very long.

[gmatov]

Nissan,

Do you know that for a fact, or are you surmising?

You are missing my point. The leaf blower is trying to move air, it simply can't "blow your hand off it", as you say, and I'm not too sure of that. I've never felt the need for one, so can't go out and check its output pressure.

However, it does indeed build pressure, with a 3 foot or so pipe and a flattened "nozzle" at the end. There is drag in the pipe, and a restriction of the pipe itself, not to mention that same nozzle. You can't move that volume of air, in that size pipe, without a rise in pressure

When you put your hand over the nozzle, you don't cause it to go to zero pressure, you simply get it to the max pressure that type of impellor, in that particular machine can maintain. Your hand isn't just resting on the nozzle, as if it were lying on a table, you are tensing against that particular pressure. And the pressure doesn't continue rising because, for this application, they did not need to design an efficient impeller, one that could force even more air into that closed tube.

Once you have equilibrium on the intake and discharge it just churns the air in the impeller itself, no air going out, so no air coming in.

Try it on your shop vac. Plug the discharge, then hold your hand over the intake. You will feel very little suction, if any.

And, I said above, that at the maximum boost range of your engine, so I've read elsewhere, on this forum, you may get up to 2 BAR of boost, 29 1/2 PSI

I'm not sure if the turbo guage is set at absolute or atmospheric, 2 BAR, I would assume atmospheric, and at idle, you would be at, perhaps, .7 BAR, the NA ideal of about 21inches of vacuum. So, at 1 BAR, you are at free flow, you can get all the air you need, and when you go faster, you get the turbo to produce as much air as the engine needs, with a positive pressure, as much as another BAR, another 14.7 PSI.

At some point, however, you are going to get to the point where your turbo, unless oversized, cannot deliver the air your engine needs, and "volumetric efficiency" falls off, the engine starts to gasp for air, and the power produced plateaus, you quit gaining speed because you are out of breath.

One advantage of this leafblower idea is that you would have all that instant response at the low end.

Ah, well, probably hit the sack, now.

Cheers,

George

[Hit_N_Run-player]

If this whole electric super/turbo charger worked, dont you think more racers/drivers would actually be using them?

[gmatov]

I never said it was a GOOD idea, just that it is not infeasible.

No, I think money is no object to a race team, but weight is.

A turbo big enough and a motor strong enough to give enough air to an 800 or 1000 HP engine would probably throw the whole car out of kilter, handling wise.

When they mount a Roots type blower, for instance, it's in the center of the engine, all the weight distributed on both front wheels.

They take a lot of horses to drive, too. Most, if not all, that I have seen pictures of, are driven by 2 inch or wider v-belts, although it's possible they are using variable speed pulleys.

The ones I have worked with, at various times over the past 40 years, have been driven by 4 or more 6L belts, or direct coupled, or on GM diesels, gear driven.

And, of course the air stops coming out when you put your hand firmly over the end of the hose, but the pressure in the hose doesn't go to zero, just as when you shut off the air hose from your shop air compressor, the pressure in the hose doesn't drop to zero. The impellor is still "compressing" the air in the hose, ie, not allowing it to just gasp back out through the now useless impellor, that is no longer moving air.

Now, I know, you're thinking "Aha, gotcha, there's a whole tank full of air still there, so of course there's still pressure."

But, do the same with a tankless compressor, and the hose is still charged, if there's a pressure switch, or a pop off valve, or if the motor even dies from overheat. The hose still has the system pressure.

Your leaf blower would, without a doubt, provide extra air to that motor till you got to a demand it could not keep up with.

I think that my NA Audi is 10:1 compression. My turbo Audi was either 8.2:1, or 8.3:1, or maybe even 8.8:1, as my book shows those ratios. They did not make those different ratios so that they would cover everybody"s bases, they did it because a NA engine gets air at atmospheric, and FIs are fed a "compressed" charge of air, ie, too much air for a 10:1 ratio, same as maybe 12 or 13 to 1, maybe more. The turbo force feeds it to bring it to about 10:1 equivalent

You try to compress that air, your compression pressure is going to skyrocket, cracked pistons, bent rods, not to mention, if it ran, you dont have the injectors to deliver enough fuel to make a rich enough mixture in the fuel-air charge, lean burn, hot as hell,there go the valves, piston crowns, head bolts probably stretch, bent rods, ad infinitum.

God, all these cans of worms, we're opening.

Long post, hope it's not too boring.

Cheers,

George

And just because I said you ARE compressing air.

[nissanfanatic]

Sure have tested it. They barely make 1psi. Turbines are high speed devices. Why is it that normal exhaust driven turbines spin in excess of 100,000rpm and even some these days surpassing 150,000rpm?

[gmatov]

Tip speed, pure and simple.

The higher something spins, either the smaller it has to be in diameter, or the more exotic the alloy, and exotic alloys,to the point that they are using ceramics in some of the higher rotation devices.

The more exotic the alloy, the higher the manufacturing cost.

The higher the manufacturing cost, the higher the cost to you, the consumer.

The higher the cost to you, the consumer, the fewer the sales, so the price won't fall to where you can afford it.

Off topic, of course, but they are having a few problems with the polycarbonate DVDs, because they spin so fast at 16X, they burst into thousands of pieces, and that's at approaching 32,000 RPM!

What are you gonna do with a titanium impellor at 150,000 RPM?

Have you looked elsewhere? The housing is designed to contain the shrapnel!!!! They aren't sure they'll take the turns!

As to the Knight electric pulse device, it looks exactly like the vacuum drives on my dust collector in my woodshop, with an open frame DC motor installed.

1k deposit? What the hell does it cost, in the long run?

Cheers,

George

[nissanfanatic]

Well thank you for the belated tech lesson, but that is exactly the reason why a leaf blower will not work as a power adding device.

I believe your whole post was in regards to centrifugal force. Materials also have some to do with lag as the less mass and weight of the impeller, the less rotational inertia aka time it takes to reach speed.