By far the best upgrade you can do to your Mazda3 MPS is to install a device able to retune the ECU. The most common option here in New Zealand is the Cobb Accessport. This allows custom performance maps to be uploaded, which you can first download online for varying modification levels from a range of e-tuners all over the world, including Purple Drank and Freak Tune. They will take your data-logged information and, within the hour, send back a suitable tune.
Cobb has five different performance packages available online, with tunes to suit. Stage one, for example, is a simple re-flash with an upgraded panel filter. As you upgrade your car, you can simply add the upgrades into your Accessport, and it will adjust the tune to suit, then self-learn to ensure it’s perfect. The Cobb Accessport also reads your engine parameters in real time and displays them as gauges on the LCD screen. This eliminates the need for bulky gauges, as you’re able to cycle through several gauge combinations on screen. If you’re into racing, the Accessport allows you to set up flat-shift shifting and launch control, so you’re best able to build boost pressure on the line at the drag strip or maintain boost pressure between gear changes. In factory trim, the ECU closes the throttle electronically near redline by as much as 80 per cent. This was done to reduce wear on driveline components, but, if you look at a dyno sheet for a factory example, you can clearly see the powerband drop off. Once the Cobb is fitted, that will be remedied, and you’ll have 100-per-cent throttle right until redline. Note that in factory form, the MPS has a boost-control limit in first and second gear.
Another benefit of the Accessport is the ability to load ‘valet’ and ‘antitheft’ maps.