Author: Mark Modaressi

The Evo is a great car out of the box… amazing steering, stiff suspension, monster Brembo® Brakes, AWD, and a powerful turbocharged engine is always a nice combination. So what could the Evo be lacking?  Well, the Evo doesn’t require anything for performance, but after driving for a few weeks you may start to wonder what boost levels you are running. That’s when you notice the lack of a quality boost gauge!  Mitsubishi does offer an overly expensive accessory gauge pack that includes a very small boost gauge, but it’s located in the bottom cubby making it nearly impossible to monitor while driving.

We decided to use the aftermarket to find a quality boost gauge to fit to the Evo for montoring purposes.  It’s always nice to know your running correct boost levels. After searching for the best gauges to use, we finally found it… Defi.  We purchased a Defi boost gauge (Black face, 60mm, metric units) and Defi control unit I from SPI Power Excel, the US distributor for Defi gauges.

Defi Link gauges are unique electrical gauges in that they are all controlled by a special control unit (required). With the control unit, the Defi gauges can perform a powerful list of actions:

In addition to the above features, Defi Link gauges use, what is called the “Daisy Chain” system. With this system, all you need to do is connect one Defi gauge to the other… no need for additional wiring or splicing. Once the new gauge is connected the control unit can begin controlling it immediately. You can daisy chain up to 7 gauges onto one control unit.

One word best describes the Defi boost gauge… quality. All Defi gauges come with the required parts to install the unit into your vehicle.  The only splicing needed was for the control unit (4 wires total – constant power, ignition on, lighting, and ground), but after that, it’s a plug and play affair. The boost gauge came with all fittings, harnesses, hoses, and the sender to make for a clean install.  The installation instructions were in Japanese, but SPI Power Excel has a set in English that you can print off their site.

We chose to install the boost gauge on the steering column for easier reading while driving. It’s important to place the gauge in a location where you can still view the stock instrumentation.

Once the gauge was installed, it was apparent how easy it was to read from the driver’s seat. The numbers are very large and clear and the warning system notifies you if you exceed the max boost level (pre set by you). At night, the gauge lights up a bight green and while it doesn’t match the stock amber gauges, the green illumination offsets just right… almost like having an Apline unit in the car.  To view the gauges lit up running the start up sequence please cick here.

We installed the Defi control unit on the driver’s side of the center console for easy access. Our first order of business was to setup the warning level to help catch our attention in case of a spike in boost, etc. Using the control unit is a breeze, just click the select button to bring up the warning set feature for the gauge, then use the up and down buttons to adjust the warning value. The gauge that’s rapidly blinking is the one that’s being modified, so it’s always easy to know what gauge your setting even with multiple gauges installed. Pressing select again will iterate through the rest of the gauges (if available).

With a large feature list including data recording, warning levels, and more, the Defi system has proven to become even more of an asset then we ever expected… and we thought gauges were just for fun

Stay tuned for part 2, when we relocate the stock head unit in order to fit a set of 3 Defi gauges and also add a turbo timer to help cool the turbo.

Installing the Defi Control Unit:

There are 4 wires that need to be spliced. We used the cigarette lighter and radio harness to splice into. You need to make sure to use a constant power wire for the Defi control unit in order for it to save information into memory after the car is turned off. Here’s a table describing the wire connections:

Installing the Sender Unit:

Once the control unit is wired, you need to install the sender and run the wire through the firewall.

1. Use the existing bolt located in the picture below to mount the Defi sender.
2. Locate the fuel pump, which can be found on the passenger side. You will now be using the supplied t-connector to allow the sender unit to receive boost readings. The hose connecting to the fuel pressure regulator pis too small for the supplied t-connector, so remove the entire hose and cut up the supplied hose to replace the stock hose and connect the sender unit using the t-connector.
3. Once you’ve connected the hoses using the t-connector, make sure to zip tie the connection points in order to prevent the hose from popping off by accident.
4. Now that the sender unit is connected, you need to run the wire through the firewall and to the control unit. There is a hole available on the passenger side of the Evo. Remove the plasic cover and run the sender wire harness through there.  You should find it come right through where the stock glove box is located.  You should not need to remove the stock glove box to get to the wire once you’ve run it through a little.

Now that you’ve installed the sender and control unit, it’s just a matter of installing the gauge in the location of your choice (we chose the stock steering column.  Use the provided connections to connect the sender to the control unit and the control unit to the boost gauge.  We ran the wires along the inside of the center console and behind the steering column so that they are hidden from view.

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