Best Performance Upgrades for Subaru WRX and STI in Canada
The Subaru WRX and STI have one of the most active aftermarket communities in Canada — and for good reason. The FA20/FA24 engine (WRX) and EJ257 (STI) respond well to modifications, the AWD platform handles Canadian winter roads, and the aftermarket support is enormous. This guide covers the most effective bolt-on upgrades for WRX/STI owners, all available at MyPartsGuy.ca in CAD with no duties.
Stage 1: The Foundation Upgrades (Under $800)
These are the modifications that make sense before anything else — improving efficiency and responsiveness on an otherwise stock car.
Cold Air Intake
The FA20 and EJ257 both respond well to improved airflow. An aFe Power Momentum or Takeda intake removes the restrictive OEM airbox and replaces it with a high-flow system. On the WRX VA (2015–2021), expect 8–15 hp at the wheels with a proper intake — more when paired with an accessport tune. The K&N 63-Series AirCharger is a slightly more budget-friendly alternative that delivers comparable gains.
Canadian winter note: Position the filter away from the front bumper opening and monitor for water ingestion during heavy slush. Both aFe and K&N heat shields help with this.
Performance Brake Pads
The WRX and STI's OEM brakes are adequate but the stock pads fade quickly in spirited driving. Hawk HPS 5.0 pads are the most popular WRX/STI street upgrade — improved bite from cold, better fade resistance than OEM, and low dust for daily driving. STI owners who track their car regularly should step up to Hawk HP Plus front pads and keep HPS 5.0 on the rear.
Upgrade Cost:
- aFe Takeda Intake: ~$450–$550 CAD
- Hawk HPS 5.0 front pads: ~$165–$200 CAD
Stage 2: Handling and Driver Feel (Under $2,500)
Lowering Springs
Eibach Pro-Kit springs for the WRX/STI drop the car approximately 25–35mm — enough to noticeably fill the wheel wells and lower the centre of gravity without compromising daily driveability on Canadian roads. The progressive spring rate handles potholes and highway joints better than stiffer coilover springs would at the same ride height.
For more aggressive drop and better body control at the expense of daily comfort, H&R Sport Springs are the alternative — popular among STI track day drivers who want more from their suspension than the Eibach can provide.
Coilovers
For enthusiasts who want full adjustability, KW Variant 2 or Variant 3 coilovers are the premium choice for WRX/STI. KW's stainless steel construction handles Canadian winters well, and their damping tune for the WRX/STI platform is respected across the community. Bilstein B16 coilovers are the value-conscious alternative — reliable monotube damping with 16-position adjustment.
Upgrade Cost:
- Eibach Pro-Kit WRX/STI: ~$450–$550 CAD
- KW Variant 2 WRX: ~$2,200–$2,600 CAD
- Bilstein B16 WRX: ~$1,400–$1,800 CAD
Stage 3: Power (Under $5,000)
Cat-Back Exhaust
A cat-back exhaust is the most impactful sound upgrade and delivers meaningful power gains when paired with a tune. MBRP's downpipe-back system for the WRX/STI is one of the best-value options in Canada — T-304 stainless, properly tuned for the EJ257 and FA20 exhaust note, with significant flow improvement over stock. For a more refined sound with Borla's characteristic tone, Borla carries WRX and STI applications in S-Type and ATAK configurations.
Intercooler (WRX)
The WRX's front-mount intercooler is a restriction point under sustained boost — especially on hot summer days or during track use. Mishimoto's WRX performance intercooler is a direct-fit upgrade that significantly improves charge air cooling, reducing heat soak and maintaining power output under extended hard driving. Most WRX owners notice the biggest difference in summer track days and back-to-back hard pulls.
Build Order Recommendation
- Intake + brake pads — immediate feel improvement, works on stock tune
- Accessport tune — get the most from Stage 1 parts
- Suspension (springs or coilovers) — handling transformation
- Cat-back exhaust — sound and power
- Intercooler — supports sustained performance in heat
All of the above are available at MyPartsGuy.ca, priced in CAD with no duties or brokerage fees. Use our Shop by Car tool to find confirmed fitments for your specific WRX or STI year, or browse by category:
Intakes • Suspension • Brakes • Exhaust • Cooling