2002 Chrysler Sebring Convertible GTC
Performance Projects

As you know, I am interested in performance modifications. Since there are practically no companies out there (including Ma Mopar) that will support 2.7L V-6 performance, I've decided to go ahead with my own projects.

Here is a list of projects I'm working on:

• Manifold Tuning Valve Controller
• Indiglo Instrument Cluster Gauges
• True Head-Up Display

Manifold Tuning Valve Controller

This project will be based off the Freescale 68HC11 (what else?) and will allow me to control the manifold tuning valve and short runner valve found in the 3.5L engine that I have installed into my car. I might even include a section that will control the variable displacement clutchless A/C compressor. We'll see...

Indiglo Instrument Cluster Gauges

I wanted indiglo instrument cluster gauges, since my old Limited had them, and I thought they were pretty cool. I went ahead and ordered a electroluminescent (EL) sheet from an electronics supplier, and set about the project.

I discovered that, in order for the gauge itself to light up properly with no dim spots, at least 1/2 of one side of the gauge face must receive power from the inverter that actually powers the EL backing. I have not yet installed the gauges into my car, because I am looking into a way to interface the inverter into the car's interior lighting circuit. This is somewhat harder than it sounds, since the interior lighting circuit is actually a pulse-width modulated 80 Hz square wave, with its duty cycle corresponding to the desired light intensity. The inverter, on the other hand, expects a constant DC voltage. Therefore, some sort of low pass filter is necessary to power the inverter from the interior lighting circuit.

Oil Pressure Gauge Installation Mounted on A-Pillar

True Head-Up Display

I wanted a head-up display, such as can be found in both fighter aircraft and in the newer high-end GM cars. To this end, I researched ways into reading the car's internal data network.

I found out that the car uses a standard SAE J1850 VPW network, which has a defined timing protocol and a defined electrical waveform. The standard itself is pretty easy to find at the SAE website. The car uses this network to pass messages between the PCM, BCM, CMTC, factory radio, and instrument cluster in a standard SAE J2178 data format. Again, this is pretty easy to find on the SAE website. ELM Electronics sells a little PIC-based SAE J1850 interface chip, that uses a 20 MHz crystal, and that acts as a bridge between the J1850 network and a standard serial interface. This is what I'm using.

I decided to use a Noritake-Itron 64x128 pixel vacuum fluorescent display (VFD) for the actual HUD display. This unit is kind of tricky to program, but I was able to get it to display some text after figuring out the VFD's quirks.

Homebrew Head-Up Display, with a "Hello, 2GSS!" message

I currently am looking for a decent 5 VDC power supply to power the VFD. A normal linear supply, such as would be made from a 7805 voltage regulator, is not sufficent to provide the approximate 1 A requirement for the VFD, without having to resort to a noisy forced air cooler. Other than that, the unit is almost ready for in-car testing.