How our AV2CAN took the WRX from the showroom to the rally stage!

Transforming a showroom-spec Subaru WRX into a competitive rally car isn’t easy - especially when the goal is to keep costs down, retain OEM reliability, and pass homologation. But that’s exactly what the team at Maximum Motorsport set out to do.

The WRX Challenge cars, developed for the Subaru Australia WRX Challenge, are designed as a stepping stone into the world of rallying - a chance to experience Subaru performance in its natural habitat. The challenge? Build something safe, competitive, and cost-effective for entry-level motorsport.

 

Laying the Groundwork: Testing First, Tuning Second

Maximum Motorsport reached out to us early in the project to discuss options. Our advice in these situations is always the same: test the systems before making assumptions - and test they did.

Modern vehicles are packed with safety systems designed for road use: stability control, collision avoidance, traction control - all aiming to keep occupants safe. But on a rally stage, when you’re sliding sideways, jumping crests, and driving on loose surfaces, even the best-intentioned electronics can become a liability.

 

 

When Factory Electronics Fight the Driver

Initial testing showed the WRX was a solid base for competition. But the electronics didn’t like being pushed outside their comfort zone.

Factory systems are tuned for months to handle road conditions. Rally-specific tyres on gravel? That’s way outside their calibration window. The result was constant electronic intervention - fighting the driver and hindering performance.

Disabling the systems wasn’t simple either. In older cars, you might pull a fuse or two. But on modern platforms like the WRX, that approach backfires. Subaru’s safety protocols detect faults, triggering limp modes that cut engine power and limit braking.

 

From Proof-of-Concept to Plug-and-Play

The team initially verified the concept using an aftermarket MoTeC ECU to control the engine. It worked — but wasn’t financially viable for a budget-limited, entry-level rally series.

This is where our systems integration expertise came into play.

By studying the OEM systems, we developed a solution using our AV2CAN board and custom firmware. This allowed us to work with (or integrate with) the factory CAN-Bus network - the internal “nervous system” of the car — to unlock full performance from both the OEM ECU and braking systems without compromising factory diagnostics or safety features.

The final result was a plug-and-play package: complete with a mounting solution, documentation, and homologation-ready specs - tailored specifically to the WRX Challenge platform.

 

Rally-Ready, Road-Smart

Thanks to this work, the WRX Challenge cars now compete using full OEM electronics. Fault finding, diagnostics, and factory programming are all retained - ensuring reliability, maintainability, and technical transparency into the future.

By making the cars accessible both financially and technically, this solution lowers the barrier to national rallying and helps continue Subaru’s proud motorsport legacy in Australia.

 

The Takeaway

This project showcases what’s possible when modern engineering meets clever integration. If you're planning to build a competition vehicle from a modern platform - whether it's for rally, tarmac, or track - reach out to us.

We can help you avoid months of troubleshooting and accelerate your program with a bespoke AV2CAN integration. From ECU tuning to CAN-Bus firmware, we bring the tools and experience to unlock performance - without compromising the systems your car depends on.


Photography by: Jack Martin Photography