GTech Pro Expandable Gauge System Install - New-School Functionality
Taking All The Guesswork Out Of The Equation
From the March, 2009 issue of Chevy High Performance
By Sean Haggai
Photography by Sean Haggai
This isn't just another ordinary tachometer with basic rev functions. It's much more advanced. GTech has found a nice niche to apply all of its latest technology into something we can put to good use in our street machines, and it's called the GTech Pro Expandable Gauge System (EGS).
No doubt, there's a surplus of options at your fingertips to keep an eye on engine stats. But what if you could get most of what you needed in one easy-to-read display? The GTech Pro EGS allows you to keep an eye on basic engine parameters such as battery voltage and of course rpm, but also provides you with plenty of cool added features to play with. Things like 0-60 and quarter-mile times, a skidpad g-meter, wideband air/fuel ratio monitoring, and even the ability to datalog days at the track with an easy recall function at the push of a button.
The GTech Pro EGS can be as elaborate or simple as you like and gives you an incredible number of options, many of which have never been available until now. This could be the last tachometer you ever buy. And since it's expandable, it means you can keep adding functions, including an eight-channel input module for driveshaft speeds, differential temperature, oil pressure, exhaust gas temperatures, and any other sensor you can think of. Should you need a 24-channel input upgrade, then GTech also offers a 2MB module upgrade. For '96 and newer vehicles, you have the option of an OBD-II interface module, which allows you to monitor a wide range of parameters such as speed, throttle position, fuel pressure, short- and long-term fuel trim, and everything else computer-related. There's also the wideband oxygen sensor to keep tabs on the air/fuel mixture and, lastly, an accelerometer module. If you're not looking to invest in the entire system just yet, then we do recommend at minimum the optional sequential shift light. These shift lights are fully programmable, starting the lighting sequence 500 rpm before the preset redline. Best of all, it can also be used as an adaptive alarm for any number of parameters.
All said, this is a great system that's completely digital with endless possibilities. The install wasn't difficult, requiring a few hours at best with basic handtools and a little wiring know-how. If you're looking for an affordable do-it-all system that can datalog while offering a multitude of functions that GTech is known for, then this is the system for you.
What We Did
Added GTech's newest technological bad-boy to our Nova
Finally something for the big kids to play with
Starting at $340
To kick things off, we applied...
To kick things off, we applied some antiseize to the wideband sensor to prepare it for its home in the bung we had previously welded on...
...We positioned the bung...
...We positioned the bung just after the collector in the exhaust pipe on the driver's side, which would give us plenty of room to run the wires.
For demonstration, we went...
For demonstration, we went ahead and plugged in the wideband sensor to the EGS controller underneath the car...
...We decided to keep the...
...We decided to keep the wire looms away from as much debris and water as possible, so routing the wires and connections through the front subframe was our best option.
We then placed the loom through...
We then placed the loom through a rubber grommet in the firewall and fed the wires into the cabin.
O2 Sensor Wiring Key
Our wideband wire loom consisted of six wires with an additional two terminal jacks. The two terminal jacks will be plugged into the back of the GTech tach later on.
Red For 12V power source...
|Red ||For 12V power source (with 5A fuse) |
|Blue ||Must be grounded |
|White ||Must be grounded |
|Yellow ||Will not be used |
|Brown ||Will not be used |
|Black ||Will not be used |
Following the wiring key,...
Following the wiring key, we went ahead and took a trip to the local auto parts store, where we picked up a 5A fuse. With the fuse, we connected the red power wire from the GTech to a 12V ignition power source we found under the dash.
The blue and white wires were...
The blue and white wires were grounded to an additional wire that had already been grounded to the chassis under the dash. We used a splicer connector to get the job done without damaging the original wiring. The splicer gives us the ability to tie two wires into one.
RPM Signal Wiring Key
Our rpm signal wiring consisted of five more wires. However, only four are used and the opposite end has a USB style connector which will connect to the back of the GTech tach.
|Black (thin) ||Must be grounded ||Red ||For 12V power source |
|Black ||Must be grounded ||Green ||For tach signal |
|Orange ||Only used for demo versions, so it must be grounded in normal operations |
We started with the green...
We started with the green wire and connected it to the coil. This wire communicates with the tachometer, telling us the rpm. We ran the wire across the firewall and again through the grommet and placed it underneath the dash.
The additional red wire must...
The additional red wire must be powered to another 12V power source under the dash. The rest of the wires (both black wires and the orange) must find another ground source. Obviously, we found the most solid ground we could under the dash with a bolt through the firewall.
We then plugged in the USB-style...
We then plugged in the USB-style connector into the back of the GTech tach.
What's left to plug in? In...
What's left to plug in? In order for the GTech to take advantage of its daisy-chain function, the remaining two black wires from the EGS wideband must be plugged in. Since we are only using one-sensor operation, we inserted the terminal jack in the plug with the "In" symbol. We took the other wire coming from the EGS ("Out" symbol) and plugged it into the serial bus port, completing the wiring.
Initial Setup Our controller...
Our controller module must be calibrated for proper use. This is called sensor heater calibration, and it should be performed every time there is a new sensor connected to the controller. In our case it is a new setup, so we had to unscrew the O2 sensor from the bung. This exposes the O2 sensor to free air. Following the instructions, we performed these steps.1. Leave the sensor disconnected from the controller.
2. Turn on the ignition; power on the controller for 20 seconds.
3. Turn off the ignition; power off the controller for 20 seconds.
4. Connect the sensor to the controller (while sensor is exposed to air, not in the exhaust system).
5. Turn on the ignition; keep the controller power on for at least two minutes.
Next, we could really dig...
Next, we could really dig into the system and begin programming alarms and view parameters for the datalogger. We performed all these functions through the main menu by scrolling and giving a positive click with the scroll wheel. It couldn't have been any easier to use and set up.
We also told the GTech that...
We also told the GTech that a wideband sensor had been installed.
Once the GTech had been wired...
Once the GTech had been wired and calibrated, we began tucking away any extra wire length to give it a neat finish and double-checked all the connections.
We decided the top of the...
We decided the top of the steering column would be the best spot for the tach. The tachometer is too large to fit under the dash, plus we already have our three-gauge pod installed there. Placed here, we can keep an eye on things and adjust various parameters on the fly much more easily--not to mention keeping our eyes on the road.
EGS Modes G-Meter The GTech...
The GTech Pro EGS also gives its users the ability to measure g-force values during acceleration, braking, and hard cornering. Once we plugged in our three-axis accelerometer module, we had the option of displaying those values and even recording them for playback. What's the benefit of the g-force function? We now have a solid indication of power gains or losses during tuning.
Datalog Saving our data is...
Saving our data is another thing the Pro EGS does. Plus, the addition of the 2MB memory module leaves 24 folders for logging data one hour at a time. The great feature about this is that the user has the ability to go back and view what the car was doing--whether under hard acceleration or braking. Got a spike in the air/fuel ratio and didn't realize it? This very function will let you know when and where it's occurring, giving you the ability to fix it.
Adaptive Alarms The adaptive...
The adaptive alarm function can be used to keep an eye on the engine temps (OBD-II), battery voltage, air/fuel ratio, and more. Once your specific parameters are set, as soon as any one function creeps out of the safe zone, an alarm sounds and displays itself by flashing on the screen.