Vonnen 2019 Porsche 911 hybrid: full details and first drive

The electronic control of the flat-six is completely unchanged, too, the Vonnen Shadow Drive’s control unit only reading CAN bus data regarding the throttle position, to allow it to add its electric boost when required. The PDK here gets a re-flash, to counter the slippage from the clutches would otherwise occur but otherwise the car doesn’t know the Vonnen Shadow Drive is there. 

The system can be entirely off, with no electrical assistance at all, while the Street mode adds 90lb.ft of torgue when the accelerator is between 40-60%. Sport mode adds 80lb.ft between 65-95% throttle and an Overboost mode adds the full 150lb.ft at the same rate as in Sport mode.

The system is hugely flexible, too, Moreland says that it can conceivably be fitted to any 911, manual or PDK, standard or tuned, naturally aspirated or turbocharged right back to 1965, though earlier cars would need some additional microswitches and sensors to monitor inputs. 

It’ll fit in the Boxster and Cayman, too. Along with the 991 PDK 3.4 Carrera it’s fitted in here, Vonnen is currently applying it to a GT3 for further development. The cost presently is $75,000, which is huge, but it’s pioneering tech, which adds big performance without having any detrimental effect on emissions. Here, in California, and, increasingly, worldwide, that’s hugely significant.   

Driving Vonnen’s Porsche 911 hybrid

Forget hybrid tech for economy or brief electric-only urban motoring, the Vonnen Shadow Drive is for performance. There’s nothing inside to highlight it’s fitted - if you ignore the power inverter located under the rear window, Vonnen saying it could be positioned out of sight if customers prefer. 

There’s a smartphone attached to the dash, too, which is nothing unusual today, only it’s running an app showing the status of the batteries, motor and the boost it’s delivering. 

Switched to off the system does almost nothing, save starting the standard 350hp 3.4-litre flat-six engine and operating the stop-start system in traffic. Switch to Street and the changes are subtle at first, the need for the 40% and above throttle meaning you can drive around it. Where it really aids is flexibility in bigger gears, allowing you to be lazy with the gearbox, the motor generator unit adding that 90lb.ft at low revs, increasing tractability in traffic. On faster roads it’s more apparent, yet the electrically charged performance seems subtly applied. That is, until you glance at the speedometer. 

It’s deceptively quick, it so linear and progressive in its delivery that you’ll find yourself carrying way more speed than you think. Near silent, too; there’s only a slight, not unwelcome, electronic pitch audible above the ordinary sounds you’d associate with the 911’s boxer engine. In Sport and Overboost modes the greater performance is more obvious, though there remains subtlety to the way it operates that’s counter to usual performance upgrade compromises.