Electric Supercharger?! (adaptable for fuel economy?)
 

How our electric supercharger works

Sounds like an interesting yet easy supercharger.
I'm curious if it's adaptable for fuel economy (reduce pumping losses by forcing air into the intake)?

Any thoughts (or is this one of those fail concepts..)?

The energy "conversion" losses from using electric-motor drive versus direct-engine mechanical drive say it's not worth it...however, the ability to 'cycle' the electric-driven SC on/off as necessary is certainly a benefit, albeit only briefly.

Step back a bit and use it as belt drive.

Is there sense in a supercharger at all? :|
WAI with supercharger? But then go all the way with turbo (but then .. not good for FE?)

Simply adding a turbocharger to an existing engine will probably not do anything for FE. However, putting a smaller engine with a turbocharger into the a vehicle that had a larger 'normally aspirated' engine can help (for example, putting a 4cyl turbo engine into a vehicle that previously had a V8 NA engine) could give an improvement in FE.

"Real" example:
- 2012 BMW 328i 2.0 4cyl Turbo 6spd: 240hp, 23mpg city, 34mpg highway
- 2010 BMW 335i 3.0 6cyl NA 6spd: 230hp, 18mpg city, 28mpg highway

(I put "real" in quotes because I don't know for sure if the aero, gearing, weight, tires, etc are equivalent between the two different model years, all of which can impact the EPA ratings... and all of the 3-series BMWs have turbos in 2012 while none did (in the USA at least) in the 2010 year... but the the comparison should be relatively close... 1 liter less but with turbo gives more HP and better FE for the newer model vs the older model with the larger NA engine)

Of course, as with most things, 'it depends' ... a large car with a turbo engine that is sized too small could cost FE since the driver would be inclined to floor it more often just to get going.

Wow! Only $10 for the construction plans. That thing wouldn't make any useable boost pressure, even for a weed eater.

Ahem...a while back hot rod magazine took 2 leaf blowers and hooked them up to a car.

Google "leaf blower supercharger hotrod magazine"

I haven't posted enough to toss you the link but its a pretty fun read :thumbup:

I think the electric supercharger offers some advantages, especially if it can be adapted without influencing manifold airflow when not in use. The percentage of time when you need the ability to boost engine power is very small, while the much smaller engine can run at lighter vehicle loads with higher BSFC. Addtitional energy could be recovered when deceleration of braking events are needed.

Since vehicles are evolving into greater percentages of electrical driven steering and cooling systems, then larger alternators with greater charging capacity will be used anyway, as engines go beltless for everything but the alternator, and even beltless altogether if the alternator was driven off the timing chain or balance chain.

I know many here think they are a farce, but for me I just don't feel that way. In fact I think, since engines are almost always operating with some throttle restriction, maybe that same restriction could be utilized to create a small amount of energy that could provide the power for the very low percentage of time when boost was necessary.

regards
Mech

I like the concept of an "electric throttle" too, but this thing is so unicorny it ain't even funny. Well... I guess it is, I laughed and smirked when I opened the link.

http://image.turbomagazine.com/f/885...percharger.jpg450cfm at 8 psi, required 18 to 22 hp,

Read more: Thomas Knight Turbo Electric Supercharger - Tech Review - Turbo Magazine

little squirrel cage heater blower will not cut it.
however ..

little

I am going to stick with my exhaust driven supercharger thingy.

With my car when driving at a steady speed the turbo puts out a steady 2-3 lbs of boost, a electric leaf blower could provide 2-3 lbs with out to much draw.
I bet they have some cheap battery powered leaf blowers, that may suffice, i would test the output in lbs before i went to far with the idea.
It should be possible to measure a leaf blowers force, in lbs.

Realistically 10 lbs of boost or more should be the goal.
Although 5 lbs would be helpful, but barely.

...reminds me of the childrens' Three Little Piggies line "...and he huffed and puffed and blew..." the air down the carburetor!

How much volume? Versus what the engine needs?

I think I'm with Old Mechanic on this. The idea could be useful to help downsize an engine, and you would only need to power the compressor at need. Don't know if this application of the idea could really work or not, though.

There's been one somewhat-popular "electric supercharger" a few years ago that was total bunk. Testing showed about what you would think: A little more torque off-idle, and then flow got choked at higher loads and RPMs.

-soD

For fun i looked at some leaf blowers.
Most battery powered blowers were only 60-90 cfm
most electrics around 150cfm
Gas blowers can go as high as 600cfm

1 tiny turbo like the ones put on the tdi's run at 15 lbs boost under load.
I suggest a used Turbo and a rebuild kit for it for anyone considering the electric supercharger.

while i like the idea of electric forced induction. about the only one i like is the e-ram; most of you will call it a bilge pump fan.

e-Racing :: OFFICIAL SITE :: The e-RAM Electric Supercharger from e-Racing Motorsports

i don't think so; if it's designed and built properly multiple sets of an axial compressor will produce a pressure increase of 1.4:1 at max per set of rotor and stator.

each set would weight way less than any other form of forced induction, and could be spun up with a 12volt hobby r/c motor; making it light weight and capable of producing some boost.

i think that thing that thomas knight made is a retarded design, and weights more than twice(not including the batteries needed to run the thing) what that m62(or is it an m90) would weight otherwise. along with less boost than it should be capable of producing.

if it was me, i still like mad max's supercharged car; electro magnetic clutch just like your average automotive a/c unit(mercedes and acouple of other manufactures have used them in the past).

oh and for squirrel cage fans, not fast enough; and aren't a centrifugal compressor. about as much as a ducted fan is not an axial compressor.

+1 on the use of A/C "electro-mechanical" clutch for ON/OFF control!

Electric superchargers are a horrible idea, especially if you're thinking about efficiency. Lets quickly review what you're thinking about doing. You're using electricity generated from the gas engine through the alternator to now put more air and fuel into the engine. Count up the conversion losses! If you're going to use electricity for anything, it should be for direct propulsion, not shoving air into an engine.

...agree, 100%:

Id considered something like this for my Insight. Any psi will make a seat of the pants feel increase. Hopefully the few psi that could be generated would not require preminum fuel either. Since I have a plug in kit, I could easily power it with that and use a switch under the gas peter for WOT operation only.

I had a supercharged tacoma with the trd supercharger. It can be driven when the super charges is not belted. Either way I got the same mpg. I got 18 mpg regardless of how I drove and 16 when towing a car. THis was basic driving, not FASing or anything beyond sidewall psi on the tires, sticking to roads with 45 mph and running 33 inch off road tires. :eek:

The other option is a chemical intercooler. I saw one on the power block a few weeks ago. I believe it was like 300 bucks, it could use windshield washer fluid and a qt of fluid would last for a few miles at a good spray pattern for some monster v8 engine.

The trouble with this super-spiffy eRam Electric Supercharger is... it doesn't work.

Dynamometer Runs conducted on 07 February 2004 - Base vs. Electric Supercharger Comparison

The trouble with this super-spiffy eRam Electric Supercharger is... it doesn't work.

Dynamometer Runs conducted on 07 February 2004 - Base vs. Electric Supercharger Comparison

I did a set of dyno runs back about 8 years ago, and this pile of junk was tested, as delivered and hooked up per instructions. While the eRam did in fact deliver increased output levels over baseline, the increases ( +0.42 HP and +1.78 ft-lbf of torque) are so small as to be meaningless.

The Thomas Knight electric supercharger is an example of just how much power is required to make real levels of boost. This shiny bilge fan that eRam sells does not deliver. The supposed gains on the eRam website can be attributed to removing restrictions present on the factory induction system.

And notice the products at eRAM are sold out and available 3-15-11.They need to update their website. :D

Green Car Congress: CPT developing 48-volt electric supercharger for micro-mild hybrids

regards
Mech

never said it worked or that it was worth what they were asking for it, but those numbers could be attributed to operator error(did you do more then one run for each variable?).

actually thomas knights(he made that around 2003-04 i think) is more a handy man's special; considering you can now a days get a 5-7kw r/c motor that can no load spin up to 10k rpms.

got any pictures of the inside of the e-ram?

Doesn't matter how fast they spin. It's how much positive pressure they can generate. Thomas Knight's motors had a 15 hp draw. That's about what it would take to make positive pressure on a modest four-banger. (Indeed, their dynos showed that boost petered out at higher rpms on the 2.4 liter Altima they used as a test car.

5-7 kW might just cut it... probably enough to give your Jeep around... 5-6 psi of boost... :p ...the question is how much weight in capacitors or batteries you're willing to carry around? :D

yes it does, force= mass * velocity

mr. knights device was powered by 1 or 2 extra batteries required to power the 3 starter motors; and i think in the end the car was hauling around 200lbs more then it would have with a normal m62 or m90, completely making 5-6lbs of boost, negated by the additional weight.

ps. 15hp=12kW

F=ma not mv, thats linear momentum....

I read about that Altima. How many of us try to run 10 second quarter miles on our daily drive? Another point. they did not try to put a 1.6 liter direct injection Nissan engine in the Altima and then use the supercharger for the less than 1% of the time when you would need more than the 1.6 would provide.

With the advent of smaller engines ,aka Ford ecoboost, driving much larger cars, and better battery technology. I see a place for an electric supercharger as a means of lowering the fuel consumption of a naturally aspirated engine without a turbo or mechanically driven supercharger.

Having driven two cars with mechanical superchargers, a Buick Rivera and a Mercedes 230 SLK, maybe my experience means a different attitude to mechanical supercharging versus turbocharging.

I really don't think this topic belongs in the Unicorn section, but that does not change it's significance to me.

regards
Mech

That was the one I was speaking of earlier. Tested and debunked.

I still like OldMechanic's idea of using a (functional!) switchable power-adder on a small engine. The electric clutch (but still belt-driven) S/C might be a better idea than a bilge pump fan, though I do wonder how much power even the disengaged pulley takes to spin? I don't remember it being something I could turn by hand.

Due to the horrible environment that turbochargers live in, I can't see a good way of making one of those switchable. Well, maybe if "cut-outs" have come a long way since last I looked into them. But the heat, moisture, and chemicals in the exhaust are not very kind to most diverter valves that I know of.

-soD

You never want to "turn off" a turbocharger on a diesel.
It will hurt fuel economy by up to 20%.

by who; most of what i've read on the web leads to mixed results

E-Ram Electric Supercharger Testing

this guy thinks it produces additional power. Not much and it's still in the realm of error for both dyno and operators.

t vago's page suggests that it's about as useful as a cold air intake or larger/different throttle body.

ps. if you don't test something more than once; the subject of error over takes what might be good data. case in point the fuel logs

Sorry, I don't have the information any more. I found a link to it through one of the CRX-related BBSes, either the crxresource one or the crxcommunity one. This was quite a few years ago, though.

-soD

Hey, if you want to spend $300 to get a shiny new bilge fan, and test it over and over and over and over and over again, be my guest.

Post results when you do! :)

As said, F=MA. 10,000 rpm free-spinning is not quite the same as 10,000 rpm under load. A regular turbocharger will be spinning at 60-80,000 rpm under load... accelerating... shovelling air into the engine.

I have no doubt that 7 kW of motor is enough to net some positive pressure, but again, I doubt you'll get more than 5-6 psi on your 4 liter motor... looking back... maybe just 4-5 psi. Would be an interesting project... attach it to a supercharger... see how much boost it makes compared to hooking the same charger up to the belts, and how much power that boost will make.

I remember the e-charger! Bilge pumps, too! I used to search for stuff for my Prelude and I laughed at everything but OEM parts. I do not know about now, but the e-charger said that it removed 0.5 PSI of vacuum losses (or something) and provided the same amount of actual boost.

I remember someone doing the math of how much air an engine pulls in on its own and linked the manufacturer's specifications on the bilge pumps, not the fantastically unrealistic numbers on eBay. eRacing may make a bilge pump, but at least their claim that it would not fall apart and fly into your engine sounded credible.

Okay, I am going to find that leaf blower engine. :D

How bout you find a gas leaf blower, put on some wheels and a seat, steer by leaning and make a thread showing the complete build,lol.

No, what you need to do is build a special go-kart with a two-inch steel shield behind you and then drop live grenades!

Probably would be wise to install some sort of shock absorbing mechanism between the go-kart and the shield. One could carry a bunch of grenades in the cart, too, and have a ejecting mechanism to shoot them, one at a time, at a spot right behind the shield. Timing the grenade explosions could be tricky, though.

You'd always want an SUV or pickup behind you otherwise much of the blast energy will be wasted to the rear and not propel you forward as much as you want.