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Discussion Starter #1
Hey everyone. I'm planning on buying a boost gauge but I have a few questions that need some answering before I pick one out. I've done the research and am pretty confident that I'll be able to install the gauge with minimal problems. The few questions I have are as follows:

<b>What is the difference between a mechanical boost gauge and an electrical boost gauge?</b>

<b>Is one more accurate than the other?</b>

<b>Is one more simple to install than the other?</b>

<b>Would I need to purchase any wiring/tubing/fuses/etc...?</b>

<b>If fuses were needed, where on the fuse box would I input these specific fuses?</b>

<b>I would like to install the gauge with minimal disconnections (gauge cluster/panels/dashboard) and with a clean result of minimal wire showing; where would you suggest I route and hide the wiring?</b>

Thanks for your time. Detailed input would be much appreciated ;D
 

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Long post ahead:

The main difference between a mechanical and electrical boost gauge is that electrical boost gauges don't require that you run tubing all the way to the gauge, but instead you run a tube from where you tap into the line near the bypass valve and you run that to an electronic sending unit that you can mount pretty much wherever you want in the engine bay, and then you run a wire from the sending unit to the gauge in your cabin. The electrical gauges then use a little electric motor in the gauge to move the needle. The needle won't move as smoothly and usually moves in small increments (depending on the gauge, think maybe in 1/16th psi increments or smaller), but this is a very minor drawback that you really won't notice unless you specifically look for it and pay attention to it.

Aesthetically, electrical gauges are a little prettier and easier to set up and configure the way you want. Many of them have a neat little needle sweep show that they do when they are turned on when you turn on your car. Also, you don't have to worry about getting kinks in the tubing like you would with a mechanical gauge, so you have a lot more flexibility in terms of mounting and routing of wires and stuff.

Accuracy will depend on the brand you get more than the type of gauge you get. I have an STRI electric gauge and it is not accurate. It reads about 1-2psi too low. However, this is a common issue with STRI gauges, but not with electrical gauges in general (so stay away from STRI till they fix this issue). Mechanical gauges have the potential to not read accurately as well. Mechanical gauges, due to the fact that they are analog, will be more precise, but the level of precision that mechanical gauges offer is really unnecessary and hardly offsets the drawbacks imo.

My personal preference is obviously for electrical because you don't have to worry nearly as much about kinking or breakages in the tubing to the sending unit as you would if you had a long tube that you had to run all the way to the gauge like you would in a mechanical gauge.

Prosport is a good brand, autometer is another.. Defi gauges are pretty much the main "bragging rights" gauges, and are pretty nice, but also expensive and require you to purchase more than you really need resulting in your spending about three times (or more) more than necessary. You can get a decent gauge for under $100, though some brands charge up to about $150. Fastwrx.com has a decent selection, though most other sites that offer WRX upgrades will have a selection of gauges as well.

Wiring is kind of up to you. I just wrapped the wires on the fuses that were already in use. Most electrical gauges use two or three wires, one for constant power, one for switched power (when you turn the key), and one for a ground. Some gauges use four wires where the fourth wire is for illumination if the gauge has a dimming feature. It should be pretty easy to figure it all out as long as you can do simple things like stripping wires and VERY basic common sense electrical stuff. Most should also come with some basic instructions. Just make sure you disconnect the negative side of the battery before you start messing with stuff so that you don't end up shorting anything out accidentally.

You shouldnt really need to buy anything extra as long as you have basic hand tools, though you can if you like. I got some little taps that I use for grounding (the circular ones that you can stick a bolt through), and I soldered the wire to it. I also ended up replacing the tubing that the gauge came with with a higher quality tube because the tubing that came with the gauge was cheap and ended up breaking, causing a leak. Fuel hoses and other tubes will work and any auto parts store should have a bunch of them, just make sure the size will work with whatever hardware your gauge comes with. I also didn't want to cut the stock hoses so I just used a small length of hose to extend them from the T. The "T" that I am referring to is basically just a splitter that most gauges will come with that allows you to tap into the tubing that is already on the car so you can connect the sending unit.

As far as mounting, my personal favorite place is the steering column as far to the side as you can go. I mounted my boost gauge on the right side, leaving just enough clearance for the wiper control arm to have full movement. It only obscures a VERY small portion of the upper range of the speedometer, and only from one eye. Take a look at my cardomain page for pictures if you want.

As far as wire routing, I routed the wire from the driver side of the engine bay, along the wiring already on the top of the firewall in the bay to the passenger side of the bay. There is a rubber gromet thinger about a foot down from the top of the firewall on the passenger side of the turbo that wiring is already routed to, I cut a small hole in this and pushed the wiring through. It will come out above the glovebox, and you should have pretty easy access to it (you'll have to reach up and feel around for the wire probably). I then routed the wiring from there across underneath the dash behind the hvac controls (there is a lot of room back there). The fuses that I used for power, illumination and there on the left side of the driver side footwell, and there are a lot of places (metal framing and supports for the dash) to ground over there as well. You can then route the wiring that connects directly to the gauge up along the steering colum. There is a lot of room to play with and there is no one best way to do it. There are other ways to route the wiring obviously, but I thought that was the simplest in terms of ease of install and removal.

If you've never done it before, installation should take you an hour or so. However, I'm super anal and I like everything to be absolutely perfect (quadruple checking and multiple reroutes and wire management eats time) so I'm not very good at gauging installation times. I actually just removed the gauge because it wasn't accurate and it took me about 10-15 minutes to take everything back out. I'm probably going to wait for the Subaru gauge to come out, or go with a prosport gauge if I get impatient.

Feel free to ask if you have any other questions. There are also a couple of other threads with pictures I believe that will show most of the things that I referred to. If you cannot find them then I could snap some if I can find my camera.

I hope that helped.
 

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Discussion Starter #4
Wow, thank you so much for that amazing input chanke and clamsjager. I really appreciate it; I feel way more confident now and I'm super eager to buy one and install it ASAP. I'll let you fellas know if I have any questions ortrouble during installation and I'll keep you updated. Thanks again ;D
 
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