With the expertise that Porsche has baked a hybrid version into the product plan of the state-of-the-art 992-technology Porsche 911, the electrical whine and extra ahead thrust produced through this changed 991-generation 911 Carrera affords a tantalizing glimpse into the destiny. This is the Vonnen Shadow Drive (VSD) effect, an OEM hybrid conversion designed by using Vonnen Performance that, supplied you could justify the not-insignificant cost, integrates a battery and an electric powered motor into Zuffenhausen’s sports car years before the manufacturing facility gets around to it.
Insert Power Unit Here
The Shadow Drive is a smart setup that provides as much as 150 horsepower and 150 lb-toes of torque to the crankshaft of a 911’s internal-combustion engine, but without significantly tampering with Porsche’s engine laptop nor excessively adding to the auto’s slash weight. The device itself weighs 210 kilos and includes an electric motor-generator sandwiched among the engine and transaxle, electricity inverter installed on the engine’s pinnacle, and a control unit, and a small 1.Zero-kWh lithium-primarily based battery p.C. Inside the front trunk. However, the net gain is toward the simplest one hundred seventy pounds, thanks to the removal of the engine’s flywheel and starter motor, in addition to using a smaller auxiliary 12-volt battery to energy add-ons. Given the motor-generator unit’s location, the device can harvest strength and recharge the battery each from the gasoline engine and at some point of braking.
Vonne president Chuck Moreland says the machine’s relative simplicity is critical to retaining the automobile’s integrity and its riding experience—a key selling factor for Porsche owners. Unlike most hybrid structures, activating the Shadow Drive’s electric-powered enhance is purely up to the driver’s discretion. Accessing the gadget occurs thru a Bluetooth-connected telephone app, which on our check vehicle featured selectable Street, Track, and Overboost power modes, in addition to a switch to shut the machine down entirely, returning the auto to near-inventory form.
Also included are actual-time machine monitoring, statistics logging, and the potential to share information with the cloud. In a telling signal that the Santa Clara, California-primarily based Sonnen operates with the fast-moving attitude of a startup, we are instructed that the app’s Track mode will soon be renamed Sport and that the configuration of this early interface probable could be revamped in some months. Even now, the final tuning of the force system itself and how its electrons are introduced are nonetheless being tweaked.
Tuning the Thrust
When new, the 2013 911 Carrera used leveraged 350 horses and 287 lb-ft of torque from its three.4-liter flat-six, which in our checking out, became enough to get a similar 2014 version to 60 mph in 4.2 seconds with the usual seven-pace guide. Trim a few tenths from that parent with the elective seven-speed dual-take hold of PDK automated in our hybrid check automobile, the electronic brain of which Sonnen updates to use more potent grasp strain to higher manage the improved stage of torque.
Manual-prepared motors make do with most effective a mechanical adjustment to the clutch. The Porsche’s guidance and chassis stability are elegant as we pull off Pacific Coast Highway and head into the mountains above Malibu. Still, it’s the VSD’s more advantageous acceleration we actually need to gauge. We start in Street mode. Bill Davis—Vonnen’s VP of engineering and our co-pilot for the pressure—says video display units engine pace and driver inputs to feed in the electric-powered raise at element throttle smoothly. “It seems like you’re basically using a bigger-engined vehicle.”
Sport mode is a chunk extra aggressive in its power delivery, yet, as within the Street placing, it unleashes most effective 60 to 70 percent of the VSD’s ability juice. To begin with, launching this hybrid 911 feels and sounds similar to when it left the manufacturing facility. Still, soon a said electric whine engulfs the cabin as the electric motor kicks in, observed using the feeling of more thrust as if a pair of turbos have immediately spooled up. It’s here that we hit the device’s thermal restriction for the primary time.
Among the cellphone app’s presentations are a battery fee indicator and temperature readouts for the battery, e-motor, and inverter. The device has a thermal limit of 302 levels Fahrenheit, beyond which it briefly shuts down to cool. Depending on how tough you’re driving, this will appear regularly, but the cooling also takes place speedy, regularly in less than a minute or so. “We’re adjusting the cooling as well,” Davis says, “so a production model of this in just a couple of months will be capable of being pushed similarly and recover even greater fast.”
Switching to Overboost mode uncorks all the VSD’s power and “turns the dial up to 11,” according to Davis. And indeed, items in our mirrors disappear far greater unexpectedly than before as we’re driven into the 911’s seats with, particularly, more pressure. While we can not completely quantify how much faster the hybrid car is over inventory until we get one to the check song, our calculators say this example can probably eclipse 60 mph in about 3.6 seconds. We wrap up our drive by turning off the gadget, which enables us to recalibrate our senses. When active, the VSD constantly emits a low-frequency electrical whine, which receives louder and extra aggressive as acceleration intensifies. With it turned off, the 911 loses much of its newfound drama, the cabin is tremendously quieter, and its acceleration almost appears laggy without the near-instantaneous surge of electrical torque.
The Catch
The most massive number in the Sonnen Shadow Drive’s specifications is its charge—$75,000, including setting up at Sonnen’s shop—which, depending on what nook of the Porsche universe you’re coming from, can make a huge distinction within the conversion’s well worth. VSD is compatible with both guide and automatic transmissions, in addition to certainly aspirated and pressured-induction engines, each stock and modified. Initial applications are limited to the 991-collection 911 (2012 to 2019 model years), with fitments for the 981-generation Cayman and Boxster to be had in a couple of months. Compatibility with older 997- and 996-era 911s will observe rapidly thereafter, with applications for other Boxster and Cayman models and classic air-cooled 911s coming some months after that. It’s here where the VSD’s sticker rate can perhaps be most justified.
While the Shadow Drive may be visible as a novelty upload-on for nicely-heeled Porschephiles, it’s far a legitimate overall performance improvement ahead of the manufacturing unit’s own improvement curve. For newer 911 owners merely wanting a boost in energy, trading as much as a Turbo version might do the process in a significantly less difficult and much less steeply-priced manner.
But when considering the less-effective Boxster and Cayman models, especially the older 911 generations, the case will become stronger. “When those automobiles initially came out, they had been rapid for their time and had sufficient electricity,” says Sonnen’s Moreland. “But the ones figure appearance downright sluggish and weak with the aid of ultra-modern standards.” For an invested fanatic looking for modern-day energy levels from a conventional 911 without extensively altering the auto’s easy, air-cooled man or woman—and who is inclined to embody present-day generation—the price of the VSD upgrade would possibly really make the experience.
