The PX1 came with two engines: the 3.2L five-cylinder P5AT making a factory 147kW/470Nm, and the 2.2L four-cylinder P4AT at 118kW. Both run a single variable-geometry turbo rather than a sequential setup, so the factory tune is noticeably soft off idle to protect that turbo; there’s real torque sitting below 2000rpm that the stock file just doesn’t release.
Unlike the PX2 onward, the PX1 largely left the factory without a DPF, so there’s no particulate filter regen cycle to work around, which actually makes it a cleaner platform to tune. A custom calibration opens up that low-end torque and cleans up the flat spot these single-turbo five-cylinders are known for, without pushing the factory turbo or injectors past what they’re rated for.
The PX1’s single VGT turbo is a known limiting factor once you’re chasing power beyond the stock 147kW, and it’s a genuinely good platform to upgrade; without the DPF that later models have to work around, there’s less to compromise when fitting bigger hardware.
A custom calibration built around your specific upgraded turbo is what actually unlocks it; a stock-style file won’t understand the new turbo’s boost curve or spool characteristics, so you end up with mismatched fuelling, boost spikes or a turbo that never gets to do its job properly. We build the tune around the exact hardware fitted, whether that’s a bigger single unit or a full supporting package.
Where supported, transmission tuning on the PX1’s 6R80 6-speed auto isn’t about adding gears, it’s about how the existing ones are used; adjusting shift firmness and shift point RPM, tightening up the torque converter lock-up schedule so it locks earlier and holds longer, and easing off the factory torque management that dulls the shift under load.
Locking the converter sooner cuts down on slip, which is where a lot of heat gets generated under tow, so it’s as much a durability upgrade as a feel one. As with our engine tuning, this is a custom calibration matched to your specific vehicle and modifications rather than a generic file.
