View Full Version : HPSI Boost Retaining Valve Installation instructions for those w/o Meth Injection

06-05-2014, 02:21 PM
Installed yesterday. HPSI will likely revise install instructions soon as those included were cribbed from sheet for those running their Water/Methanol injection. HPSI sent me the following instructions regarding the switch for those of us not running injected meth. (as if there were any other way to get your meth efficiently!) Their instructions in black. My notes in blue.

Tools: 12 or 13mm socket with extension for battery anchor. 8mm socket for ram air. 10mm socket for battery and firewall bolts. Wire trimmer/crimper tool. Pliers and/or flat blade screwdriver. Flashlight. Dish soap. Razor blade or some sort of cutter for hoses.

DISCONNECT THE BATTERY. Remove the airbox/engine cover/right side of your aftermarket Cold Air Intake.
HPSI's instructions for installing the valve are clear enough: Mount the silver bracket on the nut on top of the valve. Attach to battery anchor 13mm bolt. Point direction of valve toward motor. Route wires to firewall behind motor. Route large silicone hoses before cutting to ensure proper lengths. I called HPSI for clarification after the valve was installed but before I cut the hoses.

The bracket included for mounting the valve to the battery clamp was a touch long so the end of it abutted the battery preventing a good purchase of thread when mounting. Cut a little off the bracket or bend the end next to the battery to shorten the clamp. The large hole on this clamp is for the brass nut on the TOP of the valve. The valve will be inverted when installed so this brass nut will be at the bottom once installed. The picture in HPSI's instructions show this in the 'valve mounting' section.

-1.If the valve is installed, that's great! You're about a third of the way already. There's an arrow on the valve showing which way air flow is going. Make sure that when the valve is installed, that arrow is pointed towards the engine or passenger side of the car. (My valve did not have an arrow on it but I gleaned from pics which way to install it. In profile, the small end of valve's 'wedge' towards engine, tall end towards driver's fender.)

-2.Pressure switch (has a brass fitting on it with a black wheel and gold cover) needs to be zip tied to the back firewall. There are some black lines running along the back of the engine bay. You can mount it there.(I had a bike reflector bracket that was perfect to attach the switch too when mounting on one of the two 10mm bolts at the back firewall. This is where HPSI suggests attaching the ground wire.)

-3.Wiring: This can be confusing. Wiring is already attached to valve for you. It's long, and you'll want to trim it down and use the trimming elsewhere for installation. (HPSI means you will use about a foot of the length you cut off the red wire to attach switch to battery positive).

-First we'll start with the valve mounted by the battery. It has two wires (red and black). (Run the wires before you cut them or attach ends seemed easier for me). I ran them along the perimeter between the battery and the fender--under the ECU (where the UniChip will be installed shortly!)The black wire needs a ring connector (included in your kit) crimped onto the end using an electrical hand tool. This one ring connector is the ground wire for the whole system. It needs to attach to something metal. There are two metal bolts (10mm) near where you mount the pressure switch, located on the back wall of the engine bay. Undo the bolt there, put your ring connector on it, and tighten the bolt back down. You can route your wire around the battery however you'd like, and if you measure out the distance before hand you can trim the wire or use wire loom to make it look nicer, whatever is your preference. Next, the red wire on the valve. You'll need to route it to your pressure switch that you attached via zip-tie at the back of the engine bay, then trim this wire saving the cut out length for connection from switch to battery positive. Use a female electrical connector that's included in the kit and using your electrical hand tool crimp it to the red wire. (You just made the third wire NOT mentioned in the included instructions.)Now you're ready to connect it to something. You'll connect it to the pressure switch. The pressure switch has little electrical terminals on it. There are three total: top "COM", middle "NO", and bottom "NC". The red wire coming from the valve will connect to the top terminal on your pressure switch labeled "COM". You just connect your female connector with the male prong on the switch.

-Next, use the left over wire and attach a female connector on one end, and a ring connector on the other. The female connector goes to the middle terminal on the pressure switch labeled "NO". The other connects to the positive side of your battery. You'll loosen a nut on the battery, slide on the one ring connector, and tighten it back down. (This is the third wire NOT mentioned in the included instructions.)

Below is a diagram. In summary, you've got one wire going from the valve to a bolt at the back of the engine bay(#1), another wire going from the valve to the pressure switch(#2), and another wire going from the pressure switch to the battery(#3).

By now your valve is mounted at the front of your battery and the switch is mounted at the firewall with wires connected. Black ground wire from valve connected to firewall; Red wire from valve connected to "COM" on switch; Third wire you cut and put ends on running from "NO" on switch to battery positive.

Time for finishing the hoses.
On the top of the engine intake manifold, below the newly mounted switch, to the left of the throttle body, you find a capped off "boost port". Carefully remove this so you don't drop it in the engine bay. Pry it off with a flat blade or pliers.

I was afraid of cutting the wrong hose. No worries. Deep breath. You're gonna cut the kinda hard plastic hose running across top of engine that's connected with a little plastic clip to the throttle body.
Cut it maybe two inches to the left of the throttle body. Exhale. Now you have an end going across the engine and another end that runs under the battery out of eyesight.

Connecting the Valve:
Make sure the Valve nozzles are tight. Rub a little dish soap inside one end of the large silicone hose and attach it to the valve nozzle pointing toward your fender. Wrap this around your battery or wherever you want it. I put it in the gap below ECU between battery and fender. You are going to attach this to the kinda hard plastic hose that disappears behind your battery. Decide how much length you want and cut the large silicone hose. Smear some dish soap in the end and push it onto the kinda hard plastic hose that goes behind the battery.
Dish soap an end of the large silicone hose and push onto the valve nozzle pointing toward the engine. This hose makes a smooth "S" bend along the left of the battery and pushes onto the remaining small hard plastic hose running over the top of the engine. 90% complete!

There's an included small silicone hose with a two inch section of bigger silicone hose on it. This hose connects from the switch nozzle to the newly uncapped 'boost port' on the intake manifold. You may want to trim this for length. Rub some dish soap into each end. Small end goes to switch nozzle; large end onto the 'boost port' on the intake manifold.

Reconnect your battery. Your clock will need to be reset, etc. Time to drive.

Boost Retention Valve Instructions: