WR310 WRX STi Performance Package

wr310 wrx sti
WR310 WRX STi Performance package puts supercar lap times and high end reliability within reach in a superbly engineered and total package


With the focus of track day enthusiasts shifting strongly towards the Mitsubishi Evolution the engineers at Willall Racing took a good long look at the GRB Subaru platform and assessed what would be required to make it an not only an EVO competitive package, but and EVO beating package in club level motorsport events. The good news is that with the WR310 package in place the STi has already proven itself on the track posting both lap records and class wins against stiff competition.


Taking away some of the inherent imprecise turn-in and suspension behaviour of the Subaru platform with properly tuned coil-over suspension has led to razor sharp response from the GRB chassis that has both front and rear ends of the car working in synergy for natural balanced handling at the limit. Hundreds of laps of suspension tuning has delivered a chassis package that is unsurpassed on this type of vehicle, with the initial compliance and damper control of WR310 giving near perfect power down and drive in all conditions and surfaces.

Braking power has also been addressed with WR310, the standard GRB four piston STi brakes not being able to stop the vehicle effective in the heat of racing conditions. A unique Willall Racing 6 piston braking system complete with 360mm rotors (which fit behind the factory rims) fully floating on 'McLaren' springs combined with WR35WS brake water cooling gives literally awesome braking performance that simply does not fade. Quiet on the road, and working with devastating power at the track, both brakes and chassis of WR310 are beyond peer.

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WR310 comes in from a wet weather testing session at Mallala International Raceway after completing a 20 lap suspension tuning session


Tuning the EJ25 based engine in the STi for both power and reliability has proven challenging for many, with imprecise tuning methods gaining the Subaru Boxer a reputation for being fragile or at least 'non-durable' in track conditions. Once more the Willall Racing engineers stood a step back from these common thoughts and analysed the situation closely through a thorough dyno tuning and track testing program before declaring the 2.5 litre Subaru mill not only as reliable as its Mitsubishi counterparts, but also more power productive due to its additional base capacity.

Careful attention has not only been paid to a strong and reliable state of tune in the Subaru engine management system, but also vital engine support systems such as the oil control and breather arrangement, which if left un-touched from the factory can cause issues in competition environments. Engine calibration can be carried out on either conventional 98 octane unleaded fuel or E85 per customer requirement.


Willall Racing offer a one-on-one product familiarity session included in the cost of WR310, held at Willall Racing headquarters in South Australia. In this two hour module our technicians will explain in depth every single part of the WR310 conversion, its advantages, and how you should best operate the vehicle to ensure both total performance and durability. This training can also be expanded further to include driver development and track testing should it be required.


As a window into the performance advantage that WR310 offers we can add track data from a number of different disciplines that give you a basic guideline as to the potential of the WR310 package.

MALLALA RACEWAY: South Australia - 1:14.70

EASTERN CREEK RACEWAY: New South Wales - 1:46.54
0 - 100km/h : 4.3 seconds
0 - 400m : 12.11 seconds

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WR310 Parked up ready for either a trip to the track for a Time Attack session, a trip up a long and punishing hill-climb, or simply a journey down the shops. One package can and does do it all!



Power: 315kw @ 5950rpm
Torque: 499Nm @ 3780rpm


98 Octane Unleaded OR E85 Ethanol compatible*
* WR310 fuel calibration needs to be specified at time of order

WR310 has proven to be a winning combination out of the box, unbeaten in Time Attack class series in 2011/2012


Engine Upgrades:

  • WR35EXX Series Full Titanium Exhaust Assembly

  • WR35DP Front Pipe Assembly

  • WR35TU Engine Management recalibration

  • 98/E85 Compatible Fuel System (including Surge tank/injectors)

  • WR35MO 10w-60 Engine Oil

  • WR35BR Engine Oil Control System

  • PRICING (Fitted): $4,550 AUD

Transmission Upgrades:

  • OS-Giken Twin Plate Clutch Assembly

  • PRICING (Fitted): $2880

Suspension Upgrades::

  • HSD Coilover suspension System

  • Willall Racing Springs

  • PRICING: (Fitted): $2015

Braking Upgrades::

  • WR Series High Performance Brake Pads

  • WR Series 6 piston 360mm fully float front brake assy

  • WR35WS Brake Cooling System

  • PRICING: (Fitted): $4400 AUD


Willall Racing cars
Willall Racing state of the art and modern installation and engineering facility that is second to none


A complete WR310 system will take 10 days for our technicians to professionally install and calibrate on your vehicle. Secure transport can be arranged Australia wide ensuring your Subaru can be engineered in the state of the art Willall Racing facility.