GReddy EGT Gauge/Probe Install

Ludachris · 11-21-2003, 06:10 PM

We all know an EGT gauge is necessary when you start changing boost levels and fuel trims. It's one of the cheapest forms of insurance we've got. This little gauge allows us to measure the temperature of the exhaust gases leaving the engine via the exhaust manifold.

Installation is pretty straight forward. You need to tap the exhaust manifold, screw in the probe, run the wiring inside the car, and wire up your gauge. I took some pics of the process below:

Here's a shot of the exhaust manifold before we got started. We removed the heat shield and got marked our number 1 runner.

Ludachris · 11-21-2003, 06:27 PM

Next, we used a center punch and lightly tapped the manifold to make a small indention. This way, the drill wouldn't slide all over when we started drilling.

We started out with a smaller bit in order to make it easier. Then once we got the pilot hole done, we jumped up to the larger bit. As we drilled, we sprayed the drill bit with WD40 in order to lubricate it a bit. This will help the bit from dulling up prematurely.

Ludachris · 11-21-2003, 06:31 PM

Once the drilling was done, I used a small magnetic tip screwdriver to get as much of the small shavings out of the manifold as I could.

Ludachris · 11-21-2003, 06:51 PM

It's time to tap the threads. We picked up a 1/4" tap at the local hardware store. We dipped it in some white grease and slowly turned it into the new hole in the exhaust manifold using the tap handle. We'd turn it a couple times, then back it out and dip it in the grease again to keep it lubricated. We ended up going down about just over half way on the tap's threads.

Ludachris · 11-21-2003, 06:56 PM

Once the hole is tapped, you can then screw in the probe fitting. I used a little bit of thread tape, even though it's not a water connection.

Ludachris · 11-21-2003, 07:02 PM

Next, we'll drill a hole in the heatshield. Once the hole was drilled, you can use a dremel and widen it up. We eyeballed the spot on the heatshield, but it wasn't easy. Make sure you triple-check it. Here's the finished product under the hood:

Ludachris · 11-21-2003, 07:08 PM

Now, on to the fun part... we ran the wire through the firewall at the steering column. It helps to use a wire hanger. You'll likely have some extra wire to coil up under the dash. Not a very good photo, but you can see the steel-braided EGT wire coming through the firewall with the clutch master cylinder rod just above it.

Ludachris · 11-21-2003, 07:16 PM

We're mounting our gauge in the center vent, so we ran the wire up behind the dash following the heater duct. We took apart the console and removed the center vents. Using a hanger (once again), we pulled the wire up through the dash - it wasn't as bad as we thought it would be.

Ludachris · 11-21-2003, 07:27 PM

The last step is to tap the power supply. Now, it's been a while since I did this install, so I don't remember what the wiring colors were, but I know I used the Chiltons manual and the Greddy instructions to get it right. You should be able to as well. I know, I know, I should have soldered my connections instead of the tacky connectors.... when I finally get my Defi's, I'll do it the right way.

Also, I had to do some filing work and a little bit of cutting with a utility knife to make room for the gauges. Greddy gauges are deeper than mechanical Autometers, so it took me a little longer to make them fit. However, since it was such a tight fit, I actually didn't have to use any glue to keep the center vent pod on. Just pressed the guages in, and they stay.

Ludachris · 11-21-2003, 07:32 PM

Well, that's it. Now have fun putting everything back together. Before you do, turn on the car and make sure you tapped into all the correct wires. Make sure the headlight switch turns on the light to the gauge, etc. Let the car warm up, and watch the needle move. :)

Here's our finished shot - EGT gauge on the left, fuel pressure on the right.

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