Mazda Performance: NZ’s best all-round GTR

Mazda performance Gtr

The Legendary GTR represents the pinnacle of Mazda Performance. Matt’s Mazda GTR started life in 1992 as a rally-ready weapon and has just been turned into rocket by todays standards.

Many years ago, DOHC turbo Mazdas were a staple in the New Zealand car scene. A combination of age, glass gearboxes, theft and the destructive nature of kiwi’s and modified vehicles has seen them become a rarity.

The GTR is the holy grail of the DOHC turbo era, and piston-powered Mazda performance in general. Matt has owned this one since they were a far more common sight.

Matt had the objective of modernising and improving the performance, whilst keeping it true to roots and maintaining a standard look. We’re pretty sure this has not only been achieved, but well and truely blown out of the water.


To piece together a strong engine that can handle far more than factory intended, the little 1800 has had the full catalogue of parts thrown at it. The combination of piston and head gasket have also been used to increase the compression ratio, making the car much more lively off-boost.

Mazda #wrc323 dyno sheet

BP 1.8L

  • PBMS prepped block
  • Factory Crankshaft
  • Eagle Forged rods
  • CP Stroker Forged Pistons
  • Balanced Rotating Assembly
  • ACL Race Bearing
  • ARP Main Studs
  • Boundary Engineering Oil Pump


The cylinder head is where power is made, so we focused on improving the flow to aid response and power goals. Our PBMS Stage 2 port and polish is the go-to for most modest builds, where the focus is to deburr, enlarge and smooth the factory ports whilst keeping the factory shape. This represents the best value for money cylinder head improvements whilst giving a great result. To promote reliability, a set of ARP headstands clamp the high flowing head to the block.

From factory these engines have hydraulic lifters that severely limit performance, which were replaced with solid units for more boost and more RPM.


High flow BP Road spec

  • PBMS stage 2 port and polish
  • Auckland Cams reground camshafts
  • Upgraded valve springs
  • ARP Head studs
  • Mazdaspeed Motorsports Developments solid lifter kit
  • Toda adjustable cam gears

Turbo upgrade

After initially running the fresh engine with the previously upgraded T04B turbo, it was obvious something wasn’t right. Rather than persevere with this outdated turbo, Matt opted to go with a high-tech GTX2867R Gen II offering from Garrett. The factory GTR exhaust manifold was modified to accomodate this turbo to keep everything looking stock. We absolutely love this touch!

ECU and EFI components

The little Mazda has received a simple and effective setup to control the engine and supply fuel.

  • Link ECU G3 with G4 software upgrade
  • Bosch 750cc Injectors
  • Walbro fuel pump


Matt’s GTR is amazing to drive on the road. In the light and iconic chassis the engine feels blisteringly quick, yet controllable. The turbo starts to whistle from around 2k RPM, just to remind you it’s responsive and ready to strike. Compared to anything else built in 1992, it feels like it has enough power and torque to win the WRC!

Screen Shot 2018-10-25 at 11.57.50 AM

On the dyno it made 227kw on pump 98 at 22psi. The future will likely see an increase in boost level, once the transmission has been upgraded to suit. We’re pretty sure that even in its current state, Matt will love driving his legendary car – we know we would!

About the author, Julius

Julius provides technical support and expertise to Possum Bourne Motorsport. He's been involved with the industry since 2009 and has stamped his mark as an industry leader.

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