That blower is actually a restriction in the airflow. An engine draws air much faster than any leaf-blower can provide. Even if it would work, the current draw would be way too high. Most electric leaf blowers draw at least 8- 10 amps @ 110 volts, so if you tried to wire to your car's electrical system, it would be pulling at least 90 amps of current from your system, which would be overwhelming to the charging system. The crazy part is, 90 amps would only power a 1.5 HP motor, which would be weak even for a leaf blower, and would stall an engine if it had to depend on it for air. Roots-type superchargers usually consume 10-15% of the crank's output to produce boost. On a motor that made 200 HP, that would require 40-60 HP to produce enough boost to step up the crank output by 50%. A 40-60 HP electric motor would need between 2,487 to 3,730 amps to run. Even with a 16-volt system, you still need 1,865 amps to push a 40 HP blower. This is why mechanically-driven pumps are required to boost the crank's output.

It would be nice if an electric motor could be used to make streetable power, but it's not even close to feasible. TK

 

What about having a gas engine leaf blower. I see that they are advertised at 325 MPH and like 5500 CFM. It could be fun to try.

 

The difference is, that flow rating is against no pressure gradient. User Fishin1976 mentioned a "positive displacement" type pump, which is what's required to push air against a pressure gradient. As soon as that leaf blower started to build pressure inside your TB or Carburetor, the pressure would bleed right through the fan blades, as they will not seal against the pressure of the compressed air trying to escape. The gas powered leaf blower, even if it had the power drive enough air, would not work because of its method of air displacement. Look inside a roots-type supercharger, and you'll find gears that force air in one-way, and do not let it bleed back out. This why it can make an actual pressure coming into the TB or carb. TK

 

I don't know. I have put my hand on the end of the outlet tube and they push very hard. That blower is pushing a lot more air than the carb can suck in. Unless you have a way to dial in more fuel for air I dont think that it would be that easy.

 

Tell us again why a turbo, set up for mechanical drive rather then exhaust drive, wouldn't work? Is it because you could never set up a mechanical drive to operate fast enough to equal exhaust drive?

 

The most pressure you can hold back with your hand over an orifice as large as a leaf blower is 1-2 psi MAX. When you hold your hand over the end of the blower, the air will bleed right through the fan, and it won't be able to make a serious amount of pressure. If you could find a way to get more air in, then the carb would be able to meter it, and match it with additional fuel. If it worked, or even helped at all, every car at the track on friday night would have one.

I'm not very familiar with turbocharging, but I know that the impeller must spin very fast, probably faster than you can feasibly drive with an external belt. I say probably because again, if it were useful, somebody would have done it, and would be running it at the track.

 

yeah...i went to an SAE seminar in the twin cities last winter on variable turbo chargers and they were talking about spin speeds of 20000-30000 rpms to get that with a belt you'd need a pretty big pulley.

 

With turbos you need a special bearing to handle those high rpms, and if you would try that with belts and such, the belt would fly apart along with the pulleys,gears, bearings due to the large amounts of cintrigual (sp?) forces would tear that stuff apart.

 

yeah...theres alot of problems with the belt drive idea, i was just stating the obvious one. if you ran a 2 inch pulley on the crank, you'd be running in the area of a 30 inch pulley on the turbo,,,,and i don't see that working real well. but your right...belt seperation, bearings exploding..all kinds of things to worry about.

 

Ok then why do superchargers work so well. I saw a 14-71 at the track the other night on a car that was running 275+ MPH. I don't know what kind of ratio that is. That pulley didn't look to big. Maybe 4 inches in diameter. Turbochargers aren't that complicated. I doubt that they actually spin that fast. I think 10,000 is probably a goodf estimate. I have been around machinery that operates at 30,000 RPM's it is very loud. We have turbos on a lot of tractors and they don't make that much noise, they do get very hot though.

 

You can make a search for belt driven gear drive superchargers, -they are available as kits for engines.

This australian news site has several types listed:
http://www.capa.com.au/main.htm

I am sure there are US sites, this is just the best one with the most info I found quickly.

There are universal kits also that make serious power, -makes me drool...

 

Matt, good question -
There is a fundamental difference in the way superchargers and turbocharges operate.

A positive displacement supercharger uses a pair of rotating 'gears' to move the air, just like a oil pump moves oil. This results in very high compressor efficencies with the trade off of a very large mechanism and higher engine load to spin it.

A turbo is not as efficient as it uses a very small fan running in the 10's and sometime over 100,000 RPM to move the air.

Other mention in this thread has been given to squirrel cage blowers, those like you see in furnaces and heaters. These have two characteristics that prevent their use in this application.

1). The don't work well with restricted airflow. If you get in front of one of those and attempt to block it off, you will see the pressure will rise to a point and the fall dramatically. I am not able to give you all the reasons, but the characteristic is there.

2). These blowers have a limited RPM range, if you try to spin them too quickly, they will not move as much air presumably due to the internal turbulence which disrupts the airflow like a propeller spinning too quickly in the water produces caviatation.

If I have made some technical errors, I apologize in advance. My purpose is to illustrate the differences between turbo and super chargers.

 

Torqueking,
While I'll agree that the pictured leaf blower is a definite restriction, I just can't understand where you came up with the amp figures for your motors. I say this because for 9 years I was the control operator in an industrial facility that ran digital scr driven multi-leg 4160 volt motors at PEAK loads of 3000 amps @ 3000hp. Granted it was a fan moving between 240,000 to 260,000 ACFM, but even the main kiln drive motor was 350hp @ 600 amps peak driving a F.L. Schmidt gear box to 5000 tons. I think you need to re-think those numbers.
Although you might think that a squirrel cage or vaned electric motor might work, they are prone, if you deadhead the outlet side, to rapping up in dead air to the point where they will trip breakers (or blow fuses). A classic case would be, yes, deadheading the air load against a throttle body. Roots style blowers are much more reliable in this case because they are gear driven, and will simply get a little hotter in dead head situations.

Yelrihseam

 

Yelrihseam,
I think the numers are pretty accurate - If you carry the calculations out in watts which is the only accurate way I know of to carry out the calculation.

The rules for AC are a bit interesting, so we'll use DC and get the point across with a little error.

Ohms law: P = E * I translated Power = volts * amps

8 amps at 120 volts = 960 watts

960watts at 12 volts = 80 amps

960/12 = 80

Hope this helps.

 

Okay, now I'm really confused. I don't want to start a war, but your on the right track. That formula is the power formula (Ohms Law says E=IxR where E is the voltage, I is the current , and R is the resistance). It looks like what you've done is taken the 8 amps by 120 volts for 960 watts, then multiplied it by a factor of 12(?). P= ExI, your formula, would be 8 amps by 12 volts, or 96 watts.

yelrihseam