Image : All Photos By Bradley Brownell

This weekend’s Rennsport Reunion VI at Laguna Seca is the world’s biggest Porsche motorsport collection, but there are a ton of cool things to be seen off of the race track as well. The vendor area seemed like a much smaller and Porsche-only version of the SEMA show, with a lot of companies debuting new product and showing off their coolest stuff there. One prime example of that was Vonnen Performance and their new aftermarket add-on performance hybrid modules for 991 and 981-generation Porsche models.


By replacing the stock flywheel and starter with a 175-horsepower flywheel electric motor, Vonnen can add a ton of horsepower without affecting engine emissions. This extra boost in power can take your base Boxster from a boulevard cruiser to a speed demon, or your GT3 from a speed demon to a supercar.


According to the above graphic found on Vonnen’s website the extra boost in power comes with a minimal weight penalty, like under 200 pounds minimal. Crucially, the electric motor is only 38 pounds, and the battery stack is just 80. Now, obviously, this extra power comes in short bursts with such a small battery pack. It’s not going to be the kind of hybrid that you can drive on full electric for your commute to work, but it can be set up in a number of ways to change how the car performs, including an economy mode for better fuel consumption.

Some of the front trunk space is taken up by the battery module, which is one of only two downsides I can see to having something like this built. The 991 and 981 Porsches share a characteristically deep front trunk, so you still retain more space up front than a more traditional supercar might. There is still plenty of space for a couple of overnight bags up there.


That other downside? A $75,000 price tag for the full base system, inclusive of installation. Vonnen says their current system is compatible with all 2012-2016 Porsche 911 (including Turbo and GT3), Cayman, and Boxster models. Now, imagine for a moment that you’ve added 175 horsepower to a 991.1 Porsche 911 Turbo S. Depending on where the electric power is deployed in the car’s power curve, you could have an all-wheel-drive hybrid hypercar with 727 horsepower on tap. And with Turbo S models trading hands for around $120,000, you’d have all that performance for less than two Woodrow Wilsons.


According to the folks I spoke to about this system, the Vonnen electric motor essentially does not communicate with the standard internal combustion engine at all. The system taps into the factory CAN BUS to “listen in” on what you’re doing with throttle position and gear changes, but it doesn’t actually tell the car anything. Effectively, when the electric power adder kicks on to provide more thrust, as far as the car is concerned, it just thinks it is being assisted by an outside force, like gravity when going downhill, for example. In other words, the engine doesn’t care what the EV motor is doing. It’s a relatively simple way to implement a complex system.

Allegedly they also have a 350-horsepower “Stage 2” hybrid in the works, which sounds like a riot. Even more interesting, Vonnen is working on a similar system for aircooled Porsches. I volunteer my 88 horsepower Porsche 912E for a 175 horsepower hybrid booster pack, if they need a test subject.