A boost gauge is an absolute must on any boosted vehicle. On a turbo charged car it will tell you not only how much boost is being developed but whether or not the boost is spiking, creeping or overrunning the wastegate. All of which are important to the longevity of the motor.
On a supercharged car however, boost is typically a fixed value dictated by the size of the pulley. Even so, a boost gauge will help you monitor the condition of the supercharger and give you a general idea of what your boost curve looks like. Both of which help when trying to troubleshoot or improve upon a supercharged system’s design. The following is a step by step guide to installing the Faze Electric Vacuum/Boost gauge onto the Comptech Supercharged Honda S2000.
The Faze Vacuum/Boost gauge is an electric, back lit gauge that is offered at a very reasonable price at your local Autozone.
Parts and Tools Needed
There are many ways to install a boost gauge but for this particular install you will need:
- Soldering iron, solder, electric tape and heat shrink.
- 2 small looped crimp ends for the 12v wire and the ground.
- 2 x 6ft lengths of 16-18 gauge electric wire.
- Crimp/stripping tool.
- Small vacuum T
- Zip ties
- Small vacuum tubing (to connect the vacuum source to the nylon line)
- Drill with various sized bits
- Some sort of sealing putty. (Automotive Goop)
- On/Off switch
Just a few things first. You can run the 12v power to the gauge from any power source in the car but make sure it is from a location that does not get power when the ignition is off. Otherwise the gauges will always stay on and drain the battery. In this install the power source for the gauge is run from the battery (+) terminal but it will eventually be tapped into the dimmer switch in the car’s dash. This will eliminate the need for the on/off switch that is currently used in the setup. This was done to ease the initial install and to allow for easy access to the power wires until all of the other gauges are installed.
To avoid removing the dash or the fenders, I decided to run the lines that need to pass through the firewall, over the top of the wall. I did this by drilling a hole just behind the firewall in the sheetmetal that lies just near the lower edge of the windshield in the area covered by the plastic. This area is accessed by removing the windshield washers and then removing the plastic trim covering this area. (Pry the trim from the edges and it will pop up. It is held in place by push rivets.)
Remove the two nuts at the arrows and pull the windshield wipers off. Then lift up on the trim and it will pop away from the body.
With the trim removed you will now have access to the area right next to the windshield’s edge. This will be a good place to conceal the wiring and allow for easy adjustment down the road.
With the trim removed, drill a large hole next to the driver’s side bracket of the trim. This will be almost inline with the driver’s side fender and hood seam as pictured.
Cut this grommet and this will become the pass through into the engine bay.
Run the Power Source
Before proceeding any further, go ahead and disconnect the battery by removing the (-) black terminal and then (+) red terminal. In this install the 12v power source for the electric gauge is going to run directly from the battery. So using one of the looped crimp ends, strip the end of the red wire and crimp the end onto the wire. Now fully remove the nut from the side of the (+) terminal on the battery cable. Slide the loop of the crimp end over the bolt end and secure the new wire to the terminal by reinstalling the nut. (Note: Once the crimp is made, tug the wire to make sure that it is secure. Also, wrap the edge of the connection with the electrical tape for extra fault tolerance) Finally, run the power wire along the back of the firewall, using zip ties to secure the line until it reaches the pass through where the grommet was removed. Pass the wire through and then snake it around the hood hinge and into the drilled hole. The wire will now be reachable from inside the car by reaching down into the area under the windshield where the pillar pod will sit. (Note: A long zip tie can be used to snake the lines a little easier. Simply pre-bend the end of the tie and then tie it to the end of the wire. Pass the tie through first and it will curl upward making the wire easier to pull though.)
The pillar pod install is covered here: Honda S2000 Gauge Pod Install (Pillar Pod)
This is the looped crimp end (the end of the new power wire) that will attach to the positive terminal on the battery.
The red line is the routing path along the firewall of the 12v power source for the gauge. Zip ties are used to secure the line so that it does not move.
Notice how the wires run around the hood hinge.
This image shows the lines passing through the drilled hole. This passes directly to the cabin where the lines can hook up to the gauge. (Note: Boost line, power and grounding lines shown in this image)
Run the Grounding Wire
The grounding wire is made just like the 12v wire but it needs to connect to somewhere on the chassis. On the S2000, I connected this wire to one of the bolts holding the FMU in place and then ran the wire into the cabin just like the 12v wire.
The grounding wire is connected to the chassis (circled) and will then pass through to the cabin along the same route (arrow) as the other wires.
Run the Vacuum/Boost Line
(Note: From this point on, make sure that all wires and vacuum lines run through the hole in the pillar pod before connecting them to the backside of the gauge. If you forget to do this the gauges will not slide into the pod because the wires will be on the outside instead of the inside.)
The vacuum/boost gauge needs to T into a vacuum source from the intake manifold. On this install, the boost line (nylon line) is run from the gauge to the engine compartment in the same manner that the (-) and (+) wires are run. The line is then T’ed into the vacuum reference for the blow off valve using a plastic T and a new length of vacuum line that connects to the nylon line by an adapter. (Note: The following images will clarify this process but suffice to say, the nylon line is hard to work with and kinks easily. In the end, a simple nipple end was attached directly to the back of the boost gauge and a rubber vacuum line was run in place of the nylon one. This line is not only easier to work with but eliminates one of the connections for added simplicity.)
If you are using the nylon line, you the included lock ring and cap to secure the line to the vacuum port on the gauge as shown. Using teflon tape on the threads, tighten the cap while taking care not to over tighten or the line will get kinked. Alternately, a small brass nipple can be attached to this port and a standard vacuum line can be used.
The boost line (arrow) will T into the an existing vacuum line from the manifold. In this case, the line for the BOV (circled) is used.
Hook Up the Power Source
(Note: The Faze gauges use a power connector that plugs into the back of the gauge. The following is a general guideline for installing these gauges with the plug already connected.)
With all of the lines now run, it is time to begin hooking then up to the gauge. First, using solder or a crimp connection, connect the 12v power line to the power input on the gauge. Depending on the gauge, this will be the red wire or the one with a (+) at the base. I used solder for this connection and heat shrink. If you use a crimp connector, make sure the connection is secure and then wrap it in electrical tape.
Strip the ends of the two wires before joining them. (Note: This image shows two wires going to 1. The 1 wire is the power from the battery and the 2 form a split, one powering the boost gauge and the other powers another gauge, covered in a future tutorial. If you are just installing the one gauge then you will have just one wire.)
The wires are then twisted together and soldered. Notice on the left the red heat shrink. It needs to be installed on the wire before they are joined.
Once soldered, the heat shrink is slid over the joint. A heat gun should then be used to shrink the wrap, making a very secure and clean connection.
(Note: I will not discuss soldering or crimping throughout the rest of this guide as the joining of all wires should follow one of these routes.)
Install the Switch (and Ground)
Since this gauge is running off of a static power source (the battery), a switch must be installed in line with the ground wire (between the chassis ground and the gauge input) so that the power can be manually interrupted when the car is shut down. In this scenario, a hole was drilled into the top of the pillar pod just large enough for the front of the switch to slide through from the back. The switch is then secured with its nut and then it is wired inline between the ground, with one of its wires going to the gauge ground and the other one to the chassis ground.
This switch is wired inline on the ground wire and is used to toggle the gauges on and off regardless of whether or not the car is on.
This is what the back side of the gauge pod looks like. 1 is the switch, 2 is the oil pressure gauge and 3 is boost. Use zip ties to secure any excess wiring and then install the gauge pod as mentioned here: Honda S2000 Gauge Pod Install (Pillar Pod)
With a flip of the switch, gauges light up and become operational.
Before reinstalling the trim around the windshield, use a dab of the automotive goop to seal the hole where the wires pass. This will prevent any leaks and will also protect the wires from vibration. Additionally, the automotive goop dries to a clear silicone and can be removed if adjustments are required later.
Seal this hole with automotive goop (a hardening sealant compound) to secure the wires and prevent leaks.
Once the trim is reinstalled, the wires are completely unnoticeable except near the hood hinge with the hood raised. I prefer this routing as it offers excellent access in the event of troubleshooting.