LEADING THE CHARGE
With 637hp, instant torque and less weight than Porsche’s modern 935 revival, Bisimoto Engineering’s latest EV project is aimed at redefining expectations of electric motoring – and the plus points are becoming increasingly difficult to argue against…
Love it or loathe it, the electric era is well and truly upon us. Escalating sensitivity over air pollution and related climate change is pushing governments to call time on the combustion engine, leading OEMS to pump billions into research and development programmes for what comes next. Don’t worry, the sun setting on the fossil fuel era doesn’t sound the death knell for car culture — as we’ve demonstrated across recent issues of 911 & Porsche World, there are many exciting reasons to embrace the next chapter in automotive history.
Porsche, of course, knows this. The all-electric Taycan shows its fondness for advanced technologies and intricate engineering, delivering familiar dailydriveable, high-performance motoring without gasoline. And while it seems as though we’re at least a generation away from a viable electric 911 in production form, California-based Bisimoto Engineering believes today’s hardware can live up to some of Porsche’s most enduring silhouettes. Even the manufacturer’s own recently revived 935 would have its work cut out keeping up with this one.
“We launched this 911 on the Toyo Tires stand at SEMA in 2019,” beams
Bisimoto’s founder and CEO, Bisi Ezerioha. “At first, show attendees were so enthralled by the car’s 935-inspired looks, they didn’t notice it was packing an electric powertrain.” He recognises housing battery packs and an electric motor where air-cooled hardware usually sits doesn’t always bring a warm welcome from Porsche enthusiasts. Indeed, we’ve lost count of the number of purists who have frowned at a classic 911 EV conversion, though most complainants mistakenly work on the assumption a perfectly good air-cooled flat-six has been ditched, which is very rarely the case. Ordinarily, converted cars are either those with failed mechanical
hardware beyond economical repair, or they’re donor cars already lacking their air-cooled underpinnings. By fitting EV architecture, these classic Porsches are being afforded a new lease of life, as opposed to being sent to the great scrapyard in the sky.
PEOPLE POWER
Thankfully, the tide is turning, not least thanks to Porsche embracing (and heavily investing in) its all-electric future, but Bisi has rarely been concerned about the reaction to his builds. With an infectious enthusiasm for highperformance engineering, he’s spent the last twenty-five years testing the limits of forced-induction engines (Hondas initially, but with a more recent move into over-boosted, fire-breathing Porsches). The quiet whine of electric driving seems almost at odds with a raucous back catalogue featuring numerous massive-output air-cooled 911s, but what better way to showcase what he claims is a bolt-in EV conversion than wrapping it in some of the wildest bodywork the 911 ever wore?! In fact, the car on these pages is a prototype of a conversion Bisimoto is planning to offer its customers. “If you want to grab a Porsche enthusiast’s attention, then aping a Kremer K3 is the way to do it!” Bisi laughs. “K3 bodywork is gorgeous and we knew our car was going to be ridiculously fast, which is why Kremer looks were perfect for the project.”
It’s been some time since this striking 911 last burned any fossil fuel — originally a late 911 SC coupe, a previous owner attempted to turn it into a dedicated track car, but the build never got off the ground, resulting in the project being mothballed in a Palm
Springs lockup from the early 2000s until Bisi’s name appeared on the car’s logbook almost twenty years later. Like so many of the classic 911 EV conversions we come across, the car’s disassembled state and subsequent electric revival probably saved it from being cannibalised and scrapped. Not that much of the abandoned bodywork has been retained, of course.
The visual side of the build was planned out in advance. Bisi called in the help of British-born designer, Andy Blackmore, to create a completely new look for the coupe, inspired by the pink-on-silver livery of 1980s Japanese motorsport outfit, Gozzy Kremer Porsche. The body panels are made using genuine K3 moulds, painted Slate Grey at Dreamworks Auto Center in Los Angeles and decorated with a contrasting Illustrious Auto Styling wrap
and an APR Performance GT-1000 dualelement carbon-fibre wing. With Raven LED headlights and Bisimoto Gurney flaps, this is every bit the modern revival.
Beneath the swollen bodywork, SC structure remains largely intact. The end goal of the project was to demonstrate an easily reversible electric conversion — bolt on, bolt off — which is why the powertrain fits within a modified EV West cradle utilising the original mounting points. Loosely related to the large drive unit powering the Tesla Model S P110D, the motor is a 403-volt liquid-cooled single-drive custom AC three-phase induction system, providing 637hp and paired with a single 9.73:1 reduction gear. A Quaife limited-slip differential helps the car to remain planted when pulling aggressively from standstill all the way to a whopping 18,000rpm redline, with both gear oil and coolant treatment courtesy of advanced Purol products.
The controller and inverter are bespoke, not only enabling the power to be dialled up, but for customers to choose the kind of driving experience they’d like their converted classic 911 to produce. To this end, delivery of torque can be altered, idle creep can be increased or reduced (much like an automatic gearbox), changes can be made to the strength of the 76kw regenerative braking system, as well as traction control and failsafes to protect the drivetrain from overheating. A CSF GT3 heat exchanger, complemented by a Tractuff filler reservoir and Vibrant Performance coolant lines running to where the factory oil cooler would have been, keeps the inverter and stator temperatures in check, but, for all that technology and the level of personalisation available, one thing remains true to the original 911 concept — the driving experience is designed to feel familiar.
ENERGY CRISIS
“Many 911 EV conversions feature hugely ugly information screens,”
Bisi frowns. “They boot up linked to a Raspberry Pi or similar. Some even command the driver to hit a series of switches in quick succession to engage start-up. Let’s be honest — nobody wants any of this. I took myself out of engineer mode and thought about how my mother might approach driving the car. She’d simply want to turn the ignition and go. With this in mind, an onboard Racepak power distribution module does all the clever stuff for you. It turns on the contactors, checks the failsafes, turns on the Bosch water pumps and makes sure everything is operating as intended. All you have to do is put the key in the ignition, turn it to position two, push the
HEAVY COMPONENTS ARE CONSIDERATELY PACKAGED TO SPREAD MASS AS EVENLY AND AS LOW AS POSSIBLE WITHIN THE CHASSIS
shifter forward to go forward, or pull it back to go backward. Everything else happens in the background. It’s all really intuitive.” He admits, however, there are bottlenecks. For a start, there’s been an almost tenfold decrease in battery costs over the last decade, but they’re the heaviest, most expensive part of the build. A balance has to be achieved between weight, cost and, arguably most important of all, range. The cells are supplied by LG Chem, as they are in the Taycan, but have roughly two
thirds less energy capacity — 32kwh, as opposed to 93.4kwh — while liquid cooling and a custom-built Dithium battery management system, which dials down the power, ensure the pack doesn’t overheat under prolonged heavy use. The Ac-only J1772 charging port (paired with an Elcon charger) is mounted front and centre, hidden beneath a 917-style polished filler cap. An Odyssey 925 twelve-volt battery takes care of the car’s auxiliary systems.
“My goal was 180 miles of range, but I’m hovering around 140,” Bisi continues. “I can’t keep my foot off the power, it’s so addictive! Reduced range is, therefore, my own fault, but it’s still better than that of my Dodge Viper, which only manages 130 miles to a tank. Battery technology is improving tremendously, and the cells are modular, meaning I’m not tied to a particular configuration. If I find something more energy dense, I can go to version two or three and improve range while keeping everything else as it is. I’m looking forward to the day when EV batteries can provide us with less weight, four or five hundred miles of range and fast charging times.” Even with current-generation battery technology, this radically overhauled 911 SC is anything but a heavy car. Tipping scales at just over 1,200kg, it’s almost 200kg lighter than Porsche’s petrol-powered revival 935, while heavy components are considerately packaged to spread mass as evenly and as low as possible within the chassis. While an original K3 would have been lighter, Bisimoto’s creation has the advantage that, having passed
California’s strict roadworthiness and (ironically) smog inspection tests, it’s a race-inspired machine that’s also fiftystate road legal. Who says going electric is a compromise?
AMPED UP
In keeping with the user-first driving experience, the cabin strikes a balance between road and track. Within the Bisimoto-built multi-point roll cage lives a pair of MOMO Supercup fixed bucket seats either side of the Quaife tip-shifter, while the dashboard has been stripped of all unnecessary instruments using a Rasant Products delete kit. Where the five-pod instrument cluster once was, Bisi has fitted an AEM CD5 digital datalogger (showing vehicle speed, system voltage and motor rpm), while
a MOMO Prototipo steering wheel, Wilwood floor pedals, an SOS Customz RS carpet kit and a matching headliner bring a surprising amount of civility to proceedings.
With a technological detour Porsche’s engineers couldn’t have imagined in the early 1980s, the chassis setup is equally bespoke, pairing Eibach anti-roll bars and specially configured KW Variant 3 coilovers with an HLS2 front-end lift kit to avoid damage being inflicted upon the APR Performance splitter. The 10x17-inch (front) and 12.5x19-inch (rear) Brixton Forged BM01 wheels scale up the K3’s staggered fitment and are wrapped in Toyo Proxes RR 274/40/17 and 35/30/19 semi-slicks, nose and tail respectively. Superb period-style turbofans keep the Stoptech Level 3 brake kit (featuring 322mm and 328mm rotors, as well as G&J hard lines) cool during punishing operating conditions, and regenerative braking from the motor means they’re not working as hard as they might when slowing the car. Otherwise-wasted energy is pumped back into the battery when doing so.
The project provided Bisi with a steep learning curve. “I’m passionate about this 911 and the potential it has for future development in parallel with Bisimoto Engineering customer 911 EV builds,” he tells us. “For all the technology packed onto this car, I love going fast, period. The point, for me, is to get from A to B in the shortest time possible. Put simply, electric motors give me the immediate torque that I need. As I’ve got older, I’ve become more aware of the impact the fumes my high-output petrol engines create. An EV conversion of this scale means I can continue to have fun with an old Porsche, but can do so without the guilt.” It’ll take a while longer to win over the sceptics, but it’s worth remembering modern powertrains and step changes in control technology have long enabled enthusiasts to push the performance of Porsche’s older machinery, and the traditional compromises for going electric are gradually declining. In our book, arming an otherwise redundant classic Porsche with modern high-output performance technology, ensuring the car’s survival long into the future, is a hard concept to loathe.