Many aftermarket performance products claim cheap, drastic horsepower gains but few live up to this claim. In the last few years there's been a rise in the popularity of "electric superchargers." Most of these are being sold by brands that are either unknown to the industry or downright unreputable. I personally know a few people that have considered purchasing one of these electric supercharger kits and I'm glad I was there to convince them otherwise.
Electric SuperChargers Myth Busted: Dyno Testing
Why don't they work?
The fact of the matter is that electric supercharger kits don't really offer much to boost horsepower. They're just a waste of money and time. The concept behind how electric superchargers are supposed to work is that compressed air is more dense with oxygen. The increased density of oxygen allows the car to burn more fuel while maintaining the same air-fuel ratio and producing a bigger bang, more horsepower. Electric supercharger kits are nothing more than a fan being powered by your car battery. Manufacturers claim that this fan is enough to compress air and boost the performance of your engine. The first problem with this claim is that most of these fans are rated at very low flow rates. They're typically very small fans originally designed for other purposes and, as a result, you're not really compressing any air at all. I've read review after review on forums where people have turned on their newly installed electric supercharger to notice absolutely no gain in performance. These kits do not improve horsepower or throttle response, if anything, they add weight and reduce the performance of your vehicle.
What about kits that do flow more air?
There are some electric supercharger kits that are rated for a significant amount of air flow, and though this is nowhere near the kind of flow rate you can see from a turbocharger or belt driven supercharger, you might be thinking that these kits are worth at least a few horsepower. Well, maybe not. The other problem with electric supercharger kits is that they only address one side of the equation when it comes to making power. A car doesn't just need more air to make more powerful combustion cycles, they also need more fuel. There isn't a single turbocharger or belt driven supercharger out there that doesn't come with a solution for increasing fuel delivery to the engine. These come in the forms of fuel pressure regulators, piggyback ECUs, standalone ECUs, ECU chipping, and the reflashing of OEM ECUs. If these electric supercharger kits intended to offer any performance gain based on the concept of forced induction, then they would need to offer some sort of alteration to the fuel system or risk running very dangerous air fuel ratios.
The reality of aftermarket parts
Every auto enthusiast is constantly searching for cheap modifications that they can install to increase the performance of their vehicle, but in reality these parts are few and far between. The first lesson I learned in engineering classes, and any mechanic can back this up, was this, "Parts can be cheap, fast, or reliable. Pick two." Of course there are exceptions to this rule, but you should always be skeptical about such wondrous claims. Without scientific data to backup their claims and with the awful reviews given around the web, electric superchargers are definitely something to stay away from. At the end of the day, everyone considering an electric supercharger is fully aware that they are buying a cheap knock off of a "real" forced induction system. Do yourself a favor, save up some money, and purchase the real deal. You'll be glad you did so in the end and come out with a much better end product.