2006 Subaru Impreza WRX Under the hood

Last update: Jul 6 2017

2006 Subaru Impreza WRX with Electric Drive

Primary Systems
12 Volt Power
Cabin Heat
Power Brakes
Power Steering
Nitty Gritty
Fuel Tank Removal
Power Cabling
Mods and Upgrades
Odds and Ends


Motor11in DC, makes about 160hp
Battery pack16kWh Lithium
Drive trainStock AWD transmission with clutch
Curb weightNear stock. 50/50 weight distribution
Charge time7 miles range per hour charging
Efficiency88 MPGe (77 city / 99 hwy)
CostCar $10K + Conversion $18K = $28K
Fun factor110%

What it's Like

Most everything in the car works like it did before the conversion, except there is no air condition or cruise control. The car has a short range and I originally intended to add more cells after I had the car working. A few months of use changed my mind. Forty miles is plenty for me. I routinely drive this car 60mi in a day, charging between trips.

Performance is good and driving the car is fun. I generally start off in third gear. The car takes off and pulls nicely all the way until 40mph, when I shift to fourth. Second gear works well for parking maneuvers but is too jerky for road starts. The overall power feels quite respectable although it is less than the 2.5L turbocharged engine. It is difficult to compare an electric motor with a gas engine. The noise of revving a gas engine greatly impacts your senses, and the torque curves are very different. The Subaru driveline has a lot of lash and flex, which leads to a harmonic surging effect on takeoff. To counter this, I hold the brake with my left foot for a moment while applying the throttle, to take up the slack.

There are all sorts of subtle sounds to hear such as the tires and drive line. When accelerating briskly, the Soliton1 controller goes into performance mode and whines. When stopped at a quiet location, you can just hear the hum of the motor cooling blower. Turning the ignition on or off makes all kinds of loud clicks from all the new relays.

The power steering and power brakes work smoothly and feel just like before the conversion. Traction balance front-to-rear seems unaffected by the major change in weight distribution. The car neither understeers nor oversteers.

Here is an instruction card I made up for occasions when I leave the car at the body shop after a fender bender, or such.

Electric vehicle operating instructions


13 Dec 2017Even stiffer rear diff bushings reduce bucking greatlyLink
22 Apr 2017Fuel gauge driver uses hall effect sensorLink
20 Nov 2016Motor temperature gauge microcontrollerLink
16 Nov 2016New DC-DCsLink
9 Oct 2016Heater temperature controlLink
20 Sep 2015Fuel gauge operating based on distanceLink
18 Aug 2015Replaced the used power steering pump with a brand new pump
2 Jul 2015Motor cooling blower delay moduleLink
30 May 2015Controller ready status by check engine lightLink
20 May 2015Replaced one bad cellLink
20 May 2015Reprogrammed charger status indicatorLink
3 May 2015Upgraded powertrain mountsLink
17 Apr 2015Cell measurements indicate BMS not neededLink
12 Apr 2015Second trunk exhaust fanLink
6 Apr 2015Inlet capLink
20 Mar 2015Charge warning light module redesignLink
8 Mar 2015Fuel door labelLink
24 Jan 2015Replaced failed solid state relay with Gigavac P105Link
4 Jan 2015Cabin heater connectedLink
30 Dec 2014Controller status indicatorLink
30 Dec 201412V system voltage displayLink
26 Dec 2014WRX pedalsLink
27 Nov 2014Fog lights as daytime running lightsLink
23 Nov 2014Added module to control charge warning light Link
8 Nov 2014Badges repainted & overlayed Link
9 Oct 2014Charger status LED relayed up to package shelf Link
5 Oct 2014Recovered seats Link
6 Sep 2014Ventilation fan rids trunk of heat from charger Link
16 Aug 2014Showed at the West Coast Subaru Show. Received Best Swap and People's Choice awards
7 Aug 2014JLD404 battery meter installed Link
4 Aug 2014Tachometer working Link
9 Jul 2014Motor temperature gauge complete Link
3 Jul 2014Added two additional straps to top of main battery box Link
25 Jun 2014Wireless access to controller Link
22 Jun 2014Cabin heater switch connected Link
18 Jun 2014Front ride height adjusted Link
8 Jun 2014Replaced some lamps with LEDs Link
6 Jun 2014Rear ride height adjusted Link
31 May 2014Sealed between battery box and body
24 May 2014Shortened aux shaft Link
24 May 2014Motor blower PWM speed controller Link
23 May 2014Added side spoilers Link
10 May 201412V battery charging monitor installed Link
4 May 2014Second DC-DC installed Link
26 Mar 2014Controller liquid cooling functional. Performance is noticeably better Link
18 Mar 2014Installed scoopless hood Link
14 Mar 2014Upper battery pack insulation panels Link
9 Mar 2014Installed motor blower speed control power resistor
8 Mar 2014Installed controller radiator Link
4 Mar 2014Connected ZEVA Fuel Gauge Driver. Appears incompatible with Subaru fuel gauge
2 Mar 2014First road test. No problems
23 Feb 2014Battery straps installed Link
16 Feb 2014Charger energized, power steering pump tested
2 Feb 2014Controller programmed Link
20 Jan 2014Rework mounting for 12V battery and DC-DC Link
4 Jan 2014Switch from Hella UP28 to UP30 vacuum pump Link
28 Dec 2013Aux 12V wiring harness installed Link
13 Dec 2013Aux fuse box mounted Link
16 Nov 2013Batteries bottom balanced Link
14 Nov 2013Vacuum pump reinstalled, relay moved to aux fuse box
17 Oct 2013Power cable installed Link
16 Jun 2013Vacuum pump, switch and relay mounted and connected
15 Jun 2013Moved shunt to engine bay
13 Jun 2013Charging inlet power wires connected Link
6 Jun 2013Custom power steering hoses installed. Motor cooling blower installed Link
2 Jun 2013High voltage fuse and shunt mounted
20 May 2013Power steering fluid drained and lines removed
13 May 2013DC-DC converter mounted
2 May 2013Charger mounted Link
27 Apr 2013Steering pump and vacuum pump mounted Link
24 Apr 2013Motor mount complete Link
16 Apr 2013Mounting for controller and steering pump fabricated Link
10 Mar 2013Motor bolted to transmission. Working on motor mount Link
3 Mar 2013Lower battery box installed Link
21 Feb 2013Starting over on upper battery rack design to orient cells upright and locate charger
29 Jan 2013Motor adapter complete Link
21 Jan 2013Trunk floor removed Link
1 Jan 2013Upper battery box complete Link
18 Dec 2012Got flywheel from machinist. Needs rework
5 Nov 2012Main battery box fabricated Link
16 Oct 2012Motor adapter housing completed Link
20 Sep 2012Batteries delivered Link
16 Sep 2012Charging inlet installed Link
29 Aug 2012Motor adapter redesign in progress
23 Jun 2012A/C wiring worked out
10 Jun 2012VSS and instrument panel grounded Link
2 Jun 2012A/C pulley designed
23 May 2012Adapter housing design finished
7 May 2012ECU removed
6 May 2012H49 brushes removed, H60 brushes installed
4 May 2012Electric heater core installed Link
4 May 2012Motor blower shroud complete Link
13 Apr 2012Adapter hub finished
12 Apr 2012Fuel tank and exhaust removed Link
5 Apr 2012Engine removed