Last update: Apr 10 2018
DIY upgrades for the 2006/2007 Subaru Impreza WRX.
The hood prop normally attaches to the left hand radiator bracket when in the stored position. Rather than install the radiator bracket, I installed the Redline Tuning struts. The kit included pop rivets for the hood brackets. I used rivet nuts instead, to allow removing the bracket. Some rattle can paint matched the brackets to the car.
Red rally stripe knob, by SickSpeed. Leather shift boot and e-brake boot with red stitching from Redline Automotive Accessories.
Subaru part number 83037FE030. This switch came stock only with the 2007 STI Limited. Subaru made just 800 of those cars.
Here is how to remove the intake resonator ("chamber" in Subaru speak).
Use Subaru part 46059FA000 to plug the input hole. Subaru leaves blocking the output hole as an exercise.
|H4510FE030||Fog Lamp Kit|
|H4518FE100WG||Fog Lamp Trim Kit, Aspen White|
|H4518FE100WU||Fog Lamp Trim Kit, Satin White Pearl|
|H4518FE100TG||Fog Lamp Trim Kit, Premium Silver Metallic|
|H4518FE100LR||Fog Lamp Trim Kit, Urban Grey Metallic|
|H4518FE100VW||Fog Lamp Trim Kit, Obsidian Black Pearl|
|H4518FE100DJ||Fog Lamp Trim Kit, Newport Blue Pearl|
|H4518FE100BW||Fog Lamp Trim Kit, Aqua Blue Metallic|
|H4518FE100PG||Fog Lamp Trim Kit, WR Blue Mica|
|H4518FE100RO||Fog Lamp Trim Kit, Garnet Red Pearl|
Yellow fog light covers from Lamin-x.
The Pioneer DEH-X5700HD keeps its memory when the power is removed which occurs frequently on a project car.
Mirror part number H501SAG100 fits Impreza 2002-2007. Mount adapter part number H501SSA040.
The 2006-2007 Impreza tail lights are mostly chrome. Tail lights should be red. The 2005 tail lights are red, and are a direct fit. The 2005 tail light part numbers are 84201FE241 and 84201FE251.
A hood from the non-turbo version of the car keeps rain off the electrics. The non-turbo car did not come in World Rally Blue, so this hood had to be painted.
Although my WRX came from the factory without a wing, here is some information relevant to 2002-2007 WRX that do have a wing. The wing contains a third brake light (Center High Mounted Stop Lamp). Impreza without a wing have a third brake light inside the cabin on the rear shelf. Many WRX left the factory without a wing, except WRX STI and yellow painted WRX. Dealers added wings to many WRX that did not already have them and they left the existing third brake light on the rear shelf in place and connected. Those cars were sold with two third brake lights.
To properly delete the redundant light, replace the rear shelf with part 65510FE100OE. This requires removing the:
Most lamps in the car were replaced with LEDs. The Philips Automotive Lighting Bulb Guide is helpful to identify the lamps. The headlamps were not replaced because significant modification of the fixtures would be needed to accommodate the LED headlights that are currently available.
In the image below, lamp A is a brake light, lamp B is a tail light and lamp C is a dual brightness lamp that is bright for braking and dim for tail light. The brightness of lamp A and C matches with brakes on, while lamp B and C match with brakes off. The designers used a trick to get the brightness levels to match. The incandescent lamp in location B is type 7443, which is a dual filament lamp even though this is a tail light only. The dim mode of lamp B is used to match the dim level of lamp C because they are exactly the same type of lamp. A dual brightness LED replacement is not required in position B.
Here are the specific LEDs used in each location of the car.
|Location||Type||Lamps||Product||Cost||Amps Before||Amps After||Amps Reduction|
|Fog||H3||2||Calais H3-CAWDC||$20||4.20 x 2||0.312 x 2||7.776|
|Brake (A)||7440||2||JLC 7440 7443 T20 Plasma||$27||1.710 x 2||0.194 x 2||3.232|
|Tail (B)||7443||2||JDM ASTAR-7443-2835-33RED||$15||0.425 x 2||0.126 x 2||0.598|
|Tail/Brake (C)||7443||2||JDM ASTAR-7443-3035-21R||$20||1.710 x 2||0.328 x 2||2.764|
|License||2825||2||Zone Tech 8-SMD T10 W5W||$10||0.322 x 2||0.040 x 2||0.564|
|Trunk||168||1||Sylvania 168/194/2825 LEDriving||$11||0.357||0.055||0.302|
|HVAC backlight||74||2||Generic eBay White||$5||0.200 x 2||0.023 x 2||0.354|
|Glove box||74||1||SuperBrightLEDs 74-WWHP3||$2||0.200||0.012||0.188|
|Power socket||74||1||SuperBrightLEDs 74-RHP3||$2||0.139||0.012||0.127|
|Key switch||74||1||SuperBrightLEDs 74-RHP3||$2||0.139||0.012||0.127|
|Turn signal||7440||4||JDM ASTAR-7443-5730-24Y||$36||1.690 x 2||0.390 x 2||2.600|
|Front parking||168||2||SuperBrightLEDs WLED-W-120||$2||0.360 x 2||0.012 x 2||0.696|
|Front side marker||168||2||JDM ASTAR-T10-5730-6Y||$10||0.360 x 2||0.106 x 2||0.508|
|Reverse||7440||2||JDM ASTAR-7443-5730-24W||$18||1.750 x 2||0.262 x 2||3.238|
The total current reduction with the fog lights on is about 11A.
The electronic flasher module is a JIYE SG252B purchased on eBay. The SG252B flashes at a sluggish rate of 74 per minute. The OE electromechanical flasher rate is 84/m. I modified the SG252B by replacing the 10µF capacitor with an 8.2µF which increased the rate to 90/m.
The Custom Accessories 37000 steering wheel cover gives you the feeling of driving a Ferrari for just $6.
In its earlier days, this WRX was an unrefined, bare bones TR (Tuner Ready) without any fluff such as side spoilers. With a fancy new power plant, the car has graduated from knickerbockers to big boy trousers. Installing these items required drilling 10 holes along the sides of the sills. To figure those hole locations, I removed the side spoilers from a similar WRX and measured. The 12 holes underneath the sills existed already. They contained plastic plugs covered with undercoat. The side spoilers come in either the new curvy style or old straight style and in body color or black. I choose old black.
The front and rear badges got decal overlays from Auto City Imports.
The steering wheel got one too.
The badges next to the key lock were repainted with red accents instead of black and blue. To remove the badges, I heated them with a heat gun, then ran nylon line behind them with a sawing motion. To reapply, I used 3M heavy duty mounting tape.
The wiring is modified so that the fog lights can be turned on even when the headlights are turned off. This allows saving some power by using the LED fog lights as daytime running lights instead of the incandescent headlights. Normally when the headlight switch is off, the headlights are not off but merely dimmed by routing power through a power resistor (the DRL resistor). The resistor simply wastes some power so that the total used is the same as if the headlights were on at full brightness.
The first step is to unplug the DRL resistor. Now the headlights are either fully on or fully off. Then, reroute the wiring as shown in the diagram below. The basic idea is for power to come to the fog light relay coil from the parking switch instead of the high-beam relay. This way, the fog lights can be turned on when the headlight switch is in the first position. You can find detailed instructions on several Subaru forums. I did not ground the yellow-blue wire from the fog light switch. Grounding that wire allows the fog lights to remain on when the high beams are on.
This 2006-2007 WRX TR came with plain black pedals. Upgrading the clutch, brake and dead pedals to the WRX style is easy. The accelerator is a bit more difficult.
The clutch and brake pedals have covers with a hard rubber lip. They can be pulled off and replaced with the WRX covers, part 36024FA010. These pedal covers are often sold in a set of three, along with the accelerator pad, part 36024FA001. This accelerator pad is intended for earlier model years and does not fit the 2006-2007 Impreza accelerator assembly.
The 2006-2007 WRX STI accelerator assembly (part 36010FE040) fits the bill, almost. It is physically compatible and has the same electrical connector, but the connector pinout differs among the turbo, STI, and normally aspirated cars. The WRX TR stock accelerator assembly part number is 36010SA060.
To get around the wiring mismatch, the connector and sensor can be moved from the old assembly to the new assembly. Thus, the original connector and sensor remain in the car. Note that the service manual advises "Accelerator pedal cannot be disassembled." It is held together by Torx head screws to discourage you. Nevertheless, disassembly is simple and the internals are straightforward.
The new hybrid accelerator assembly produces slightly different voltages at the minimum and maximum positions. The difference is enough to require recalibrating the motor controller throttle input. If I were modifying the pedal in a gas car, I would recalibrate the ECU. Alteratively, the pedal stops could be trimmed or shimmed until the voltage range matches exactly.
|Position||Before||After||Difference||% of range|
Subaru does not make a fancy dead pedal. There is an aftermarket dead pedal that looks very similar to the WRX pedals available from FastWRX. The rubber pads are attached with weak double stick tape. The small pads come off easily. The remedy is to pull them out, remove the tape, and glue them. The metal is very smooth. Scoring with an awl helps the glue adhere. Acetone removes residue left from the tape.
A pouch inside the trunk liner stows items that were previously in the spare tire well. The pouch is attached over the jack access cover with a snap kit.
Although this car does not currently have air conditioning, someday it might. When that day comes, the mod below will allow better control of the A/C compressor.
As with many cars, when you select a defrost setting, the A/C is engaged just as if you had pressed the A/C button (except the button is not illuminated). The reasoning behind this is that A/C not only cools but dehumidifies, providing maximum defogging. The mod below allows moderate defogging with heat alone. If dehumification is also needed, you can turn on the A/C by pressing the button.
Pop the shift lever cover loose to expose two screws at the base of the center bezel. Remove the two screws, then pop out the center bezel.
Remove the radio. Unscrew the heater control assembly and tip it up to expose a limit switch at the bottom right.
Unscrew the switch, pull it out and disconnect the wires with a soldering iron.
Insulate the ends of the wires with electrical tape and reverse the removal process.
The stock drivetrain mounts and bushings are very soft and occasionally cause the car to buck upon takeoff. The problem was reduced with stiffer engine, transmission and differential mounts. I recorded video of the various parts of the drivetrain in action before and after each upgrade to determine the effect of each.
The pitch stop was upgraded to an aftermarket model, the NYPPD NY-SU-011. The video shows a modest reduction in the movement of the motor and transmission. There was no noticeable increase in noise.
The transmission mount was swapped for the STI mount, Subaru part D1010FE020. This upgrade made a big reduction in the motor/transmission movement with little or no increase in noise.
The transmission crossmember bushings were upgraded to the STI Bushing Kit, Subaru part B4100FG000. These bushings transmit a lot of transmission noise into the cabin. The noise level was a deal breaker. The original bushings went back.
The differential carrier was steadied with the addition of the aftermarket Kartboy Rear Subframe Outrigger Bushings Comfort, part 1002-01-KBU-053-COMFY. These are not replacements but additions to the existing bushings. No instructions are included, leaving you with a puzzle. I found instructions here. Very good reduction in movement with little or no increase in noise.
The engine mounts were replaced with STI engine mounts, parts D1010FE110 and D1010FE120. The video shows reduced motor movement. These mounts added very little noise.
The rear differential bushings were replaced with the Powerflex PFR69-122 black/race. With these bushings, the inside diameter of the center metal sleeve is too small and does not provide enough clearance for installation of the M12 bolts. The ID is 12.1mm (0.475in). The sleeves were replaced by headless drill bushings, increasing the hole to 14.3mm (9/16in). These Powerflex racing bushings provide excellent reduction in movement with little or no increase in noise.
The rims are from a 2004 Impreza WRX STi. The rim size is 17x7.5, which is wider than the original 17x7. The tires are a quiet running summer tire, the Continental ExtremeContact DW XL 215/45ZR-17.
STI floor mats are a nice upgrade to the 2002-2007 Impreza carpet mats. The driver's mat has a reinforced pad at the wear spot. There is an extra bracket with a snap to hold the mat in position more securely. Part SCI440B202.
The STI mats are a bit larger. This is evident when laying the WRX mats on top of the STI mats. The STI mats have a more precise shape that fits the contours of the car better, particularly in the rear.
The base trim level front seats were swapped out for the high-end sport seats. All the seats got new black covers from LeatherSeats.com. The door panels were also recovered, with red accents. The factory cloth is removed to install these seat covers. These covers are not leather, but vinyl. Replacing the seat covers was easy enough to do myself. The door panels were a bit trickier; I had an automotive upholstery shop do them.