Toyota GR Yaris Stage 1 ECU Remap

Toyota GR Yaris 1.6T GR-FOUR

The Toyota GR Yaris is already a serious bit of kit straight from the factory. A turbocharged 1.6-litre three-cylinder pushing 280 bhp and 390 Nm in a car that weighs next to nothing. But Toyota, like every manufacturer, builds in headroom. There's more in there. So when this GR Yaris came into BRS Remapping for a Stage 1 remap, we were confident we'd find it

The Toyota GR Yaris Remap


The GR Yaris is built around the G16E-GTS engine, a bespoke 1.6T unit developed specifically for this car. Toyota didn't take an off-the-shelf engine and put it in a hot hatch. They built a turbocharged three-cylinder from scratch with rally-spec architecture, then homologated the road car around it.


That matters for remapping. The GR Yaris ECU responds well to tuning because the hardware is already built to handle more. The block, internals, and turbo all have tolerance beyond the factory map. A Stage 1 GR Yaris remap works with that headroom rather than pushing against it.


Stock figures are 280 bhp and 390 Nm. On 99 RON pump fuel, a well-executed Stage 1 remap consistently finds more.


Why This GR Yaris Came to BRS Remapping


The owner wanted more performance from the car without adding hardware. No upgraded intercooler, no turbo swap, no intake. Just a clean Stage 1 toyota gr yaris remap on the existing setup, done right.


That's a sensible approach. A Stage 1 ECU remap on the GR Yaris unlocks gains that are already available in the engine. It doesn't ask the hardware to do something it wasn't built for. It just removes the manufacturer's conservative limits and replaces them with a calibration that suits the car properly.


The brief to BRS Remapping was straightforward: get more from what's already there.


The Stage 1 remap we carried out


Stage 1 on the GR Yaris means a fully custom file, written specifically for this engine and this car. We took the original Toyota map off the ECU, set up our software, and rewrote the fuelling, ignition timing, and boost control for the G16E-GTS. The hardware stayed factory throughout, which is the whole point of a Stage 1.


Here's what we adjusted:


  • Boost pressure across the rev range, lifted within safe turbo and engine limits
  • Ignition timing, advanced where the engine can take it on UK premium fuel
  • Air to fuel ratios, leaned where appropriate, richened under load for safety
  • Throttle response and pedal mapping, sharpened so the car feels more alert off-throttle
  • Speed limiter, lifted (with the customer's explicit consent for track use)

The whole job, from initial diagnostics to final road test, took the best part of a working day. Every BRS Remapping Stage 1 starts with a full health check on the engine. We don't put a custom file on a car that isn't ready for it.

Stage 1 Tuning Figures


The gains are consistent with what the G16E-GTS platform delivers when the map is properly calibrated. The power comes in cleaner, the mid-range pull is stronger, and the car responds to the throttle the way the hardware always suggested it could.


A properly done Stage 1 remap on the GR Yaris is safe for the engine, the gearbox, and the GR-Four AWD system, provided the map is custom and the limits are respected. The 1.6 G16E-GTS is a strong unit with serious motorsport pedigree (it shares architecture with Toyota's WRC programme), and 310 bhp sits well within what the standard turbo, internals, and clutch are designed to handle.


Get a Quote on Your GR Yaris Remap


If you've got a GR Yaris and you want to know what a Stage 1 ECU remap can do for it, get in touch with BRS Remapping. We'll talk you through what's realistic for your specific car and setup before you commit to anything. BRS Remapping writes every Stage 1 file in-house and tests it on the car before you drive away.


Call BRS Remapping on 0161 350 0181 or request a quote. We cover Manchester and the surrounding area, mobile and in-person.