Our 750 Horsepower Electric Hybrid GT Racecar
Kels is our beloved 2003 Nissan 350z racecar that we have been racing for over a decade. The car has seen years of continuous development, has set and re-set lap records a number of times and has won a fair number of races – from endurance races to sprint and more recently Time Attack. In terms of speed, it now rivals IMSA GTD cars in terms of lap time.
The car has all of the professional motorsport features you might expect of a modern GT3 Car: traction control, 12″ wide racing slicks, motorsport ABS, 4-way adjustable dampers, and nothing but motorsport electronics throughout.
In 2019 we finally achieved the lifelong dream of doing a 1:18 at Mosport – our local international racing circuit. A famous track, known to some as a mini Nurburgring for its massive elevation changes and high-speed corners, it is one of the fastest tracks in North America and has been our home since we started racing. A 1:18 is the equivalent lap time to what GT2 cars would run in the heyday of ALMS.
After achieving our goal, we made the decision to turn Kels into a mobile development platform where we could develop and test ideas we had for motorsport electrification. The plan was to add 200 horsepower through a small motor and battery while adding less than 200lbs.
This goal is relatively conservative when compared to the current state of the art in Formula 1 and prototypes, but is a very large challenge when working with a budget ~1/100th that of professional outfits.
As of March 2020, our hybrid system is operational and has been tested on the dyno, and has advanced features that will be explained below. With the foundation now in place, we look forward to developing this car and perhaps one day, having more than 1000 horsepower from the combined VQ and hybrid powertrain.
2003 - The Original Build
2008 - We Purchase Kels - 1:33.7
After going through multiple owners and getting it’s fair share of abuse, Kels is purchased by SG-Motorsport in an effort to bring it back to Koni Challenge.
Unfortunately, the car proves to be underpowered and uncompetitive, although the team learn a lot by running two Koni Challenge races. Both races are finished, finishing 13th in the second race and beating a number of extremely well-funded teams.
2009 - Aerodynamic Development
2010 - Endurance Racing Win
Kels runs a 3hr Endurance Race with Sasha Anis and Yukinouri Taniguchi behind the wheel. We win our class and are very close to catching the 1st place overall Dodge Viper.
You can read the entire story here:
Kels then goes on to set a new RWD Lap Record at CSCS later in the season, along with some wins in regional racing. Further development is done to the car, with the addition of 18″ wheels and used racing slicks.
We then build a high compression engine aspiring for more power.
2011 - Minor Updates
Mosport Lap Time: 1:27.02
2012 - Individual Throttle Bodies, Blue
2013 - 3.7L Engine Upgrade
We change to an upgraded engine, and with fairly factory internals it produces the same power as the previous engine. There is now significantly more potential, but the results haven’t shown on the track yet.
2014 - Global Time Attack
We add a dry-sump oiling system to the car, along with some weight reduction upgrades and head to Road Atlanta, a track we’ve dreamed of visiting for a long time to compete in Global Time Attack.
We place 2nd in Unlimited RWD beaten only by an insane Corvette, and are one of the fastest cars at the event despite having half of the horsepower and far less aero than many of the other cars. Kels has the highest cornering speed at the event.
Watch a video from that event here:
2015 - Wind Tunnel Testing
2016 - Widebody And Green
We do a major race at Mont Tremblant and crash on oil in qualifying. After repairing the car and starting from the back, we hang with most factory-built racecars but eventually have an incident with a clown in a Porsche GT3 Cup Car. Watch that very exciting action here.
We also set a new lap record at CSCS in Unlimited RWD.
Kels never runs at Mosport with a proper setup but does a 1:25 with ease during testing. The car proves that it has the pace to keep up with GT3 Cup cars, however, it is seriously underpowered.
2017 - Kels Blows Up
We finally get back to Mosport to test the speed of the car with the widebody. Unfortunately, the tires we use aren’t that great, and the car only does a 1:21.9 – that’s only about 1 second faster than we had done without the widebody and sequential gearbox.
Kels’ engine throws a connecting rod late in the season, and the engine is destroyed. You can watch a video about that sad day here.
2018 - 4.2L Engine Development
2019 - Flat Floor, 500whp, 1:18.1, Hybrid build.
Our new 4.2L engine is incredible and makes over 100 horsepower to the wheels more than our previous engine. We design and build a full carbon fibre flat floor and diffuser.
We achieve our 14-year goal of doing a 1:18 at Mosport. There are tears. Watch the video here.
The hybrid development is started and before the end of the year we have the hybrid system on the dyno. Unfortunately a shaft breaks, but luckily we have ample time before the 2020 season starts.
Watch the overview of the hybrid system here.
2020 - Hybrid Build First Season, 1:15.9
Mosport Lap Time: 1:15.9
The hybrid system is working, and we finished off the season beating our 2019 Time by 1.3 seconds at Mosport, an impressive feat considering the car was far from optimized!
In 2020 a paddle-shift system was added, in addition to the Hybrid system. In late 2020 the motor was also rebuilt in-house at MPP with reduced turn stators to improve the power output at high RPM. The motor now gives the engine over 150 horsepower.
Kels also turns Silver.
Dyno video HERE
First Track test video HERE
Final Mosport video HERE
HYBRID SYSTEM OVERVIEW
We’re using an axial flux Phi-Power motor that has been custom designed for our application. Using a custom mounting plate we’ve designed in house, the motor directly couples to the engine inside the transmission’s bellhousing.
The battery was one of the largest challenges for the design of this build, because we needed something that was capable of extremely high power, with a quality cooling interface, and while being as light as possible. After a lot of research, we’ve run out of time, and have settled on a BMW i8 battery. In the future a custom liquid-cooled battery will likely be desirable but the i8 battery has great power density and the OEM reliability is hard to argue with.
We have designed some heatsinks that are bonded to the bottom of the modules to aid in heat transfer, and the battery is currently air cooled through a duct behind the driver door.
The battery is 160lbs modules only, and 175lbs including our bracketry, fuse and all high voltage cabling. The battery energy is 7.5kWh.
The Power Electronics
Kels uses a Cascadia Motion PM100DXR inverter to convert the 400 volts coming out of the battery to the AC voltage the motor needs to party. The inverter is capable of outputting 450A RMS which is capable of supporting 150kW of power.
We have an air-cooled DCDC converter installed in the trunk to convert the high voltage from the 400V battery to power the low voltage systems. This has allowed us to remove the alternator which both saved weight, and moved it rearwards.
We have designed our own power distribution box which houses the contactor and fuses for the off-board charger and DCDC, along with isolation measurement. This module communicates with our MoTeC M150EV via CAN to let the system know if high voltage is leaking into the chassis of the vehicle, so that appropriate steps may be taken.
We have used a MoTeC M150EV as the main control unit and ECU for Kels. Using the M1 Build environment, we were able to develop our own software that runs on the same unit as the main engine control. So one controller runs the engine, the traction control, paddle shift – and also manages the battery, inverter and high voltages systems.
The ECU is programmed with a number of different strategies to limit power into and out of the battery, based on things you’d expect such as state of charge, motor/inverter/battery temperature, and coolant temperature.
There are multiple different drive maps and driving modes, allowing the vehicle to operate in a full gasoline mode, hybrid mode, or EV mode. In hybrid mode, there are driver-controlled trim knobs that adjust the power output of the motor, as well as the charging and regen strategies for the motor.
The main design goals for this project were to get as much weight moved back as possible and to add as little weight as possible. We didn’t want to cheat and hang too much behind the rear wheels, as excessive polar-moment is never fun.
The heat exchanger, water pump, swirl pot, DCDC, 12V battery, high voltage battery, and power distribution box are all located behind the driver over or just behind the drive tires. The inverter and air shift compressor are mounted just beside the driver, close to the transmission tunnel.
The removal of the clutch, flywheel, starter, alternator, and clutch pedal hydraulics along with the switch to a magnesium cased X-trac gearbox has resulted in a net weight gain of just under 200lbs, keeping within our goals there. That is a big achievement considering the battery itself is 175lbs, which is significantly heavier than a Formula 1 battery for example, which supports 160 horsepower and weighs only 44lbs!
VIDEOS AND CONTENT
Here are our most popular videos of Kels in her pre-hybrid state. They are worth a watch as we’ve had our years of excitement with this car, and you get an appreciation for just how much has gone into this platform before we decided to turn it into a hybrid development platform. You can find even more on our YouTube page, as well as from our friends at Speed Academy.
And finally, here are some videos that explain the hybrid system and show it in action. We’ll continue to update this section with more videos as we produce them. Let us know if there is anything specific you’d like to see and we’ll do our best to cover it in future videos.