What Are Electric Superchargers, And Do They Actually Work?

Superchargers have been around for decades and have provided a valid alternative to turbocharging. Instead of the conventional mechanical turbocharger, is it preferable to have electronically controlled forced-induction?
What Are Electric Superchargers, And Do They Actually Work?

There’s nothing quite like a supercharger whine. That high-pitched shriek from the belt-driven mesh as it compresses air into the cylinders is one of our most loved sounds as petrolheads. Almost seen as a ‘bolt on’ application, some of the greatest powertrains ever made have been supercharged, be it Jaguar’s V8, the 5.4-litre engine from the Mustang GT500 or the 638bhp motor from the Corvette ZR1. Although Formula One has come along and used electric motors for turbocharging purposes, electric superchargers have also been floating around the internet as a possible modification in the last few years. So how do they work?

There are two types of electric supercharger. The first is more of a fan than specifically a supercharger. Attached directly to the inlet manifold, the cylindrical component acts basically as a desk fan, sucking air into the intake and then forcing it into the cylinders. You can find plenty of these contraptions on the Internet but it is essentially a big scam. These ‘superchargers’ are in fact only bilge pumps, designed to help pump unwanted water from the deck of a small boat.

Don't go near any of these 'bolt-on' components
Don't go near any of these 'bolt-on' components

Due to the small fins and relatively low speed of these pumps, they struggle to create any real form of compression. This lack of compression means that the inlet air gains little to no pressure and therefore the air entering the cylinders barely gains any energy, resulting in no real power increase.

The second type of electric supercharger uses a donor turbocharger with an electric motor attached, otherwise known as an E-supercharger. The electric power is converted to torque from the electric motor to the spinning impeller within the turbocharger which will be forced to spool up at the rate of the increase of electrical current flowing through it. Due to the purpose-built fins within the turbo, the incoming air will be compressed to a level that will pressurise the air supply to the cylinders enough to see genuine power gains.

This is the real deal. It also has a decent-sized motor attached which always helps.
This is the real deal. It also has a decent-sized motor attached which…

The electronics come in the shape of an electric motor connected to the throttle either at the throttle body in the engine bay or at the throttle pedal. This allows for the electric motor to spin the fan at a rate in proportion to the amount of throttle being applied, simulating the belt-driven action of a conventional mechanical supercharger. This motor is powered by an attachment to the car’s battery which brings up an inherent problem with electric supercharging.

Compressing air takes a whole load of energy; around 6-7bhp for every psi of boost is sapped from an engine to drive a mechanical supercharger. Applying that to electronics, a 12-volt battery will barely be capable of providing the energy needed to perform anywhere near the same capabilities of an engine’s crank. Therefore, electronic supercharger kits from eBay or any other website will generally provide little to no increase in power and may even cause a net decrease in power by sapping the charge from the battery. Although an E-supercharger can create the required boost, it still needs a large electrical supply to function to its full potential.

A 12V battery is really going to struggle to keep up with an E-Supercharger after dealing with this lot
A 12V battery is really going to struggle to keep up with an E…

Therefore, to power all of a car’s electrical equipment as well as an additional E-supercharger, a 48-volt battery would really be needed. Although, considering the sheer amount of electrical tech on cars these days, it probably won’t be long until a 48-volt unit becomes standard.

The benefits of an electric supercharger come in the form of a minimal lag time and a high rotational speed. While turbochargers can take a couple of seconds to spool up and mechanical superchargers still having some inherent lag, an electric supercharger can spool fully in as little as 0.5 seconds through the direct connection with the throttle, giving virtually instant maximum boost. Mechanical superchargers max out at around 60,000rpm whereas the electrical equivalent can reach a speed of up to 120,000rpm, even higher than most turbochargers.

A proper E-Supercharger, with the electric motor combining with the turbocharger housing
A proper E-Supercharger, with the electric motor combining with the…

If electric superchargers can be fully engineered and combined with the relevant electrical supply, they could start a new mini revolution within the current obsession of downsizing. With manufacturers having to fully address turbo lag as they create more and more forced-induction engines, electric supercharging could be an instant fix if mass produced. However due to the costs involved with the research and development of such a component - plus the impending change in power supply that would be needed to make it function effectively - it will probably be a while before we see electric supercharging properly taking off.

Mechanical supercharging on the other hand is turning into a thing of the past due to its power-sapping nature and the sheer heat created by such systems. With electronics beginning to dominate in almost every aspect of motoring however, supercharging may well be about to make a comeback. RIP natural aspiration…

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Comments

Anonymous

I can imagine a highly tuned car in the future… electric motors stripped, electric superchargers stripped… a V8 swapped NA e-car which has “f*ck environment” sticker on.

08/13/2016 - 17:33 |
0 | 6
Anonymous

In reply to by Anonymous (not verified)

I can imagine us all driving a Tesla in the future, when the prices have fallen to the point where the great and unwashed (me)can afford one.
After watching current ones spank Ferraris, Lambos and the like, who would want a turbo charged V8 anything?

12/17/2016 - 13:48 |
0 | 0
BlackD3vil

this could be used with another turbo to provide the low end power, and than stop working at certain rpm so the mechanical turbo can do its job. just to ask how much do these turbos cost?

08/13/2016 - 18:04 |
6 | 2

Like a twin-charged setup but with a supercharger with like 5 psi or something like that?

08/13/2016 - 23:28 |
2 | 0
Tasdeeq R34

👍

08/13/2016 - 18:25 |
0 | 0
Anonymous

If Im guessing it right, with the Eturbo you wont need an inteecooler, right? Since there is no exhaust gas involved to heat up the turbo housing….

08/13/2016 - 18:32 |
4 | 2
LordFokas

In reply to by Anonymous (not verified)

Well, actually the turbine housing heating up isn’t the main issue there, although it would heat up the air. The thing is the colder it is the denser it becomes, thus the more air you can fit into one cylinder, so even though it isn’t heating up you probably still want to cool it down as much as you can…

08/13/2016 - 19:10 |
6 | 0
Anonymous

In reply to by Anonymous (not verified)

Not exactly, for a situation like this, you would have a (simplified) equation like this: T1/P1 = T2/P2, so for a given change in P, you will have a change in T. Say T1 = 25C and P1 = 14.7PSI, then you boost to 10PSI, that means P2 = 24.7PSI, you then solve for T2. T2=(P2*T1)/P1 So T2 = 42C. That is why you need an intercooler, to bring that increased temp, due to the compression, back down to a reasonable temperature to have denser air, and better combustion.

08/13/2016 - 21:08 |
6 | 0
Anonymous

In reply to by Anonymous (not verified)

Compressed air is still heating up in the process, and you need to cool it down you want to have the maximum benefit. Therefore intercooler are still needed

08/14/2016 - 08:05 |
2 | 0
Stubaru

Non car guys be like: dude thats a small turbo

08/13/2016 - 19:24 |
8 | 0
Black Phillip

No.

08/13/2016 - 19:29 |
0 | 0
Anonymous

Actually those cheap bilge pumps are for pumping fresh air into the hull of a boat to air out any gas fumes that could explode. The more you know

08/13/2016 - 20:17 |
16 | 0
Anonymous

You could have an alternator running of the crank to supply power directly to the e-supercharger. Guess it mainly depends on whether or not that’s more efficient than running a mechanical supercharger, but at least it’s a whole lot easier to install than a non bolt-on regular supercharger .

08/13/2016 - 21:13 |
2 | 0
Anonymous

I think an interesting way to make an E-Supercharger system for the existing 12V electrical system on vehicles would be to have a Supercap bank and a boost converter. Under low load when the boost isn’t needed the boost converter keeps the supercap bank charged and ready to go, then when the boost is needed, the HV supercap bank is used to power the motor on the e-supercharger. Also, under cruising conditions, the natural vacuum would be causing the impeller to spin, that energy could be recouped to charge the supercap bank as well.

08/13/2016 - 21:14 |
8 | 2
Anonymous

In reply to by Anonymous (not verified)

I agree with everything except the vacuum bit, that would effectively reduce the speed of the air charge and increase vacuum to the cylinders therefore lowering the efficiency of the engine.

08/15/2016 - 01:22 |
2 | 0
Jerry De Souza

In reply to by Anonymous (not verified)

Hey man I just have a question. Agreed the supercap would power the motor but how would the motor speed be proportional to engine rpm. Like how would the motor know how much it has to spin if you understand what Im saying thanks.

11/14/2017 - 03:27 |
0 | 0
Marc Steenekamp

So that’s how the new 2017 Toyota 86 got it’s “+5 horsepower” or however much it is.

08/13/2016 - 21:19 |
0 | 0