I have been collecting parts and doing research on this for nearly 2 months. You would be absolutely AMAZED to discover how much bad, or incorrect information there is out there. I’ve found that most pictoral threads detailing I/C sprayer systems are either:
1. High $$$, elaborate, custom systems
2. Completely ghetto, non-properly functioning garbage
I’ve found that there is almost ZERO information on how to do an actual transplant of a 100% factory STI I/C sprayer system into a WRX… the RIGHT way. Not jimmy-rigged, not ghetto, with all correct parts, installed correctly, and functioning properly. Again… I researched EVERYTHING out there, and over 90% of it is completely wrong, or not worth doing.
So, before I begin, I thought I’d go ahead and clear up several misconceptions I managed to discover, usually the hard way.
1. The intercooler sprayer SWITCH should NOT be grounded. (trust me, it’s correct)
2. You need the STI spray timer relay to get the 2-3 second burst
3. Running pump power through the switch by “holding” the switch down will burn out the internal light
4. The Subaru schematics ARE correct, but they are MIRROR images of how the plugs actually look.
First things first, lets start with all the parts I used:
LEDs (I’ll explain why in the instructions)
STI I/C switch:
The switch prongs:
STI trunk carpet
STI I/C sprayer tank and pump:
Sprayer tank prongs
Various electrical supplies
STI spray timer relay (Subaru part # 88017FE040)
3/16 “L” tubes
Special female wire terminals (NAPA part # 725273)… be warned, they are $1.40 a piece. You need 9 of them, but you should get several extra
STI sprayer nozzle (Subaru part # 86636FA120)
3/16 ID tubing – 20 ft
STI sprayer check valve (Subaru part # 86634AG010)
Standard size insulated female wire terminals
A few other items were required that I had on hand – standard stuff, vampire clips, electrical tape, and LOTS of zip ties, etc.