Project Lexus SC300 Road Racer: Part 4 – Beginning the Epic Rewire


The AiM Sports MXL Strada.

Power and engine management, check. What about keeping tabs on what’s going on from the driver’s seat? I love Defi gauges. I have loved them for a long time. I had them on my 240SX and the SC300 came with them. But out they are going, in favor of this cool digital and programmable dashboard from AiM Sportline. This is an MXL Strada, which is actually kind of an old dash at this point. I had purchased it very inexpensively from Robertson Racing several years ago, before I even started writing for MotoIQ. It can display all the critical information I need, including lap times, and the price was right. No complaints.


The RaceCapture/Pro 2 data logger – open source!

One thing that my older dash does not offer is data logging. The Autosport Labs Racecapture/Pro will take care of that for me. Since the SC300 is being built into a real race car that I intend to use competitively in the future, I need to know how the car is performing so that I can make reasonable changes and measure their effect. The data logger is the key to being able to accomplish that. It will also tell me how much I stink at driving. I can hear it silently mocking me already.

As some of you may know, for my day job I work in the IT industry for the largest open-source software company in the world, Red Hat. I’m also hobbyist hack-job of a programmer, but am a fan of any and all things open source, and have been using open source software for over a decade. The best part of the RaceCapture/Pro is that it is fully open source. That’s right, both the hardware AND the firmware are available for free. Autosport Labs makes money selling built units and providing support. This is similar to the Megasquirt project.


The RaceCapture Bluetooth transceiver.

Another unique feature of the RaceCapture/Pro is that it is capable of remote telemetry. Using a direct cellular connection or, in my case, paired via Bluetooth to a mobile device, the RaceCapture/Pro can send live telemetry from the car up to Podium, RaceCapture’s website for live event data. If you want to watch me drive like a bonehead in real time, soon you’ll be able to!

The Bluetooth transceiver also allows you to use the same telemetry-transmitting mobile device as a customizable dashboard. An inexpensive tablet could be used to display everything the RaceCapture/Pro 2 knows about.

Lastly, one of the extremely powerful things about the RaceCapture/Pro is that it is fully programmable. And I don’t just mean that I can tell it when to start and stop capturing data. It supports the use of a scripting language, Lua. What does that mean? It means that I can write programs to control the operation of the logger. Back to this in a moment.


Components locked and loaded. Ready, set, wire!

With all of the main components selected — battery, engine control, power distribution, dashboard, wideband, and data logging — you might be wondering how all of this stuff is going to work together. This is where the magic of modern technology really shines and helps makes our lives easier. Some of you may be familiar with CAN bus. This vehicle communications standard was developed in the early ‘80s and has been around for quite some time. Almost every modern vehicle uses some devices that communicate with one another via CAN. And, fortunately for me, almost all of the devices that I have chosen are capable of sharing information with one another via CAN. Doubly fortunately for me, Haltech makes this an even simpler plug-and-play affair with their CAN hub!

The RaceCapture/Pro data logger can be programmed with a Lua script to read all of the information out of the Haltech ECU. The Haltech ECU and the Haltech WBC1 communicate with one another by simply checking a box in the Haltech Elite Software Programmer (ESP). The AiM Strada can read all of the vehicle status (speed, pressures, temperatures, and more) from the Haltech ECU. All of this is possible via two little wires that make up the CAN bus. There are also some other tricks I have planned for making some of these devices inter-operate a little better.

Component selection done. Car gutted. What next? You’ll find out soon enough!

XS Power

Haltech Engine Management Systems

Racepak Smartwire

Autosport Labs

AiM Sports


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