It’s been a long time since a modern car has entered the realms of affordability for tuning enthusiasts. The clean early-model Evos, GTXs and WRXs of the ’90s are long gone, but what replaced them?
There are still a few options that fit the bill, so we decided to look into some now affordable tuning platforms, starting with the Mazda3 MPS, which was released in 2007. It feels as though it was only recently that this model sold for well over $20,000, but we’ve seen them go for just over $10,000, which leaves more money in the bank for upgrades. After speaking with a wide range of enthusiasts, and a handful of tuning shops, we confirmed that there is an almost set-in-stone tuning route for these cars, so we took a closer look at the upgrades available for Mazda’s 2300cc L3-VDT engine.
The Mazda3 MPS will do 0–100kph in 5.4 seconds in stock form, and the turbocharged 2.3-litre is backed by an LSD-equipped six-speed manual gearbox.
In factory form, the L3-VDT produces 194kW (260hp) at the flywheel, has an all-aluminum block with iron cylinder sleeves, and a top-mounted intercooler. The factory turbo — although a weak point — produces around 13–14psi of boost pressure, and has been known to be efficient up to around 17.5psi, providing the correct supporting modifications are in place. So, what modifications should be done to the L3-VDT?
Before you begin adding a bleed valve, or boost controller, there are a few maintenance tasks you’ll ideally complete first. According to the experts, start off by switching over to a high-quality fully synthetic 5W-40 or 5W-30 oil, change your spark plugs to either a seven or eight heat-range plug, and install a higher-flowing panel filter. If you plan to use the car at weekends only, or at the track, the added gain from an open-pod filter will be beneficial. However, it is advised to use the factory airbox with the high-flow filter if you do a lot of around-town driving.
Another common part to fail with an increase in power is the rear lower engine mount. Several club members have had failures at the track, which just ruins the fun. Replacing this engine mount with an uprated stiffer unit is the best option. While you’re there, replacing the shifter bush in the gearbox is advised. Another recommendation is to get a base tune, which will ensure your Mazda is healthy enough to modify, and make sure your oxygen sensor is working correctly should you decide to tune your engine with maps available online.
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 reflash 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 that 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 of a factory example, you can clearly see the power band 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 ‘anti theft’ maps.
Before you go any further, we’d advise that you upgrade your factory fuel pump to keep up. A mechanical component inside the fuel pump — which physically lets through more fuel — will need replacing. This is definitely a job for a trusted mechanic.
Now that your Mazda MPS has some sort of tuning software installed, such as the Accessport by Cobb, it’s time to start upgrading. Instead of doing an exhaust system straight away, as you would have for the turbo cars of the ’90s, start by replacing the downpipe and midpipe off the turbo. These are by far the most restrictive component on the engine thanks to the cats, and will net you the most gains. Most aftermarket downpipes replace the factory downpipe and front pipe as one unit, and flow much better. People have seen around 20 to 25kW from just stepping up these components.
Once you’ve upgraded the fuel pump and front pipe, it’s time to install a full exhaust system. Again, there are plenty of aftermarket options available from the likes of Cobb, Mazda3Mods, CPE, and Corksport. At this point the new map from Cobb should mean the car is making some fairly decent power, and running more boost. Another area that provides an additional meaty gain is replacing the small top-mounted intercooler with a much larger top-mount unit or a front-mount kit. Either will net around 14 or 15kW and decrease intake-air temperatures considerably. Another beneficial upgrade for the serious enthusiast is the addition of a water/methanol injection kit, installed just before the throttle body — gains of up to 10 to 12kW have been seen.
Chassis and handling
The Mazda3 MPS is an impressive-handling and -braking machine right out of the box thanks to a rigid chassis design — which has more bracing than the lower-spec models — and sizable 320mm front rotors, apparently sourced from a Volvo. To get better handling out of your Mazda3, it’s just the same as most other front-wheel-drive platforms. Installing coilovers, and front and rear sway bars, will ensure your Mazda handles at its best. Don’t forget a set of good-quality tyres too.
Mazda3 MPS results
Just recently we’ve had the pleasure of following the Prowear NZ Superlap Series, in which a very potent Mazda3 contests each round. With the above modifications, Khan Mackesy’s example is a seriously quick piece of kit, putting several GT-Rs, Evos and WRXs to shame. The best part of this tuning path is the reliability. Khan is able to beat on the Mazda3 all day, then drive home in comfort and in style afterwards.
We can only see Mazda3s increasing in popularity at this rate, especially since they’re getting cheaper!
Photos: Rene Vermeer, Jacky Tse
This article was originally published in NZ Performance Car Issue No. 230. You can pick up a print copy or a digital copy of the magazine below: