Tuning the Toyota Celica GT4 – 350+ HP Road Car at Motorworx

At FC Tuning, we’re no strangers to the legendary Toyota Celica GT4 – a machine built to dominate rally stages but equally capable of delivering serious thrills on the road when mapped correctly. We’ve had the pleasure of working on numerous clients in the past, including this nice customer’s GT4 road car at Motorworx, with the goal of extracting reliable, usable performance without sacrificing drivability.

The Setup

This GT4 came in already boasting a healthy base of performance modifications. With a well-looked-after engine and supporting upgrades in place, the focus was on getting the most out of the setup while ensuring smooth delivery across the rev range.

On the Dyno

Once strapped down at Motorworx, we set to work calibrating the Apexi PowerFC ECU to balance power, torque, and safety. The Celica’s turbocharged 3S-GTE engine responded brilliantly to careful mapping. With optimised fuel and ignition adjustments, along with boost control refinement, the car produced over 350 horsepower with a strong torque curve that transforms the way it drives on the road.

The Result

The end result is exactly what the owner was looking for – a GT4 that feels alive yet predictable, pulling hard through the gears with minimal lag and excellent mid-range punch. It’s the kind of tune that makes the car not only faster but also far more enjoyable in everyday conditions.

At FC Tuning, we don’t just chase numbers – we tailor every calibration to the car’s intended use, whether that’s road, track, or competition. This Celica GT4 is now ready to deliver reliable performance on UK roads with all the character you’d expect from a rally-bred icon.