I have a FWD car - presumably the type of vehicle this device is targetted towards.
If you look at the suspension in the front, it is quite a bit more substantial than that of the back. The reason - the force exerted by the drivetrain propelling the vehicle has to be transferred through that suspension, along with the force of braking. Those forces occur in both directions up front.
By contrast, the rear suspension is significantly lighter. It only has to deal with braking, and since braking is front-biased, the rear suspension doesn’t have to deal with as much braking force. The design offers very little provision for transmitting propulsive force via the rear suspension, which occurs in the opposite direction as braking forces.
Unless I misunderstand this device, it’s supposed to bolt onto a vehicle like mine and suddenly provide additional power to the vehicle on the currently undriven axle. If that’s the case, it’s likely going to rip the rear suspension right out of the car if it’s at all effective at that.
All good points.
The torque number mentioned for the electric motors are comparable to that of the existing gas motor. Not insignificant.
This system looks like it restricts air flow around the brakes, which can reduce their operating life and reduce their effectiveness. You would have to wonder how this system would interact with anti-lock braking systems.
From a physical standpoint, it looks like it is best suited to a drum brake system, in which the motor components can surround the existing drum. It might not be so easy (or even possible) to integrate this with existing disk brake components.
Installing this system would be in no way comparable to changing your brakes, as the inventor claims. Unless you happen to be a pretty competent mechanic, you will have to pay someone to install this system.
When mounted on the rear wheels of a FWD car, it effectively turns the car into a four wheel drive, which might be a good thing in some situations, but it might also upset the factory efforts to ensure stability (electronic stability control systems) and generally unbalance the handling of the car, which could result in a vehicle that is dangerous to drive in less that optimum conditions.
Lawyers would have a field day with systems like this, which fundamentally alter the overall mechanical design of a car once people start having accidents with it (even if the hybrid system isn’t the cause).
Properly done, the controller for the electric motors would have to be linked into the car’s computer as more and more cars are drive-by-wire designs. Generally speaking, car manufacturers are loath to give aftermarket companies access to their software designs.
A buyer of this system would have to be aware that it would have a serious impact on the factory drivetrain warranty, if that happens to still be in effect.
Last but not least, it also compromises the utility of a car by taking up a big chunk of the luggage space.