Upgrading or replacing suspension components on your 2004-2007 Subaru Impreza can significantly enhance its handling and performance. However, ensuring that the parts you choose are compatible with your specific model is crucial. Whether you own a WRX, WRX Wagon, 2.5RS, 2.5 RS Wagon, or Outback Sport, understanding suspension fitment is key to a successful modification or repair. This guide breaks down the compatibility of various suspension parts for these Impreza models, helping you answer the vital question: “Will This Part Fit My Car?”
Struts: Finding the Right Fit for Your Impreza
When it comes to struts, the 2004-2007 Impreza WRX and RS models share specific fitments. This means certain aftermarket and OEM options are directly compatible with these models, simplifying your upgrade process. For these models, the spring and strut top fitment remains consistent with the stock struts.
Specifically designed struts for 2004-2007 WRX and RS models include:
- Koni Inserts: These are not complete struts but inserts, requiring installation into your existing strut housings. (For detailed install instructions, refer to resources like the NASIOC forum).
- Ohlins Fixed Perch Struts: Known for their performance and quality, these struts are designed for direct fitment.
- STi Version 8 OEM Struts (2004 USDM STi): Genuine Subaru STi parts from the 2004 USDM STi model are compatible.
- STi Version 8 Arai Pink Struts: Another performance-oriented OEM option from Subaru’s STi line.
For owners considering struts designed for the 2002-2003 Impreza, there are workable solutions, although they require additional considerations. These struts, including popular options like KYB AGX, KYB GR2, Tokico HP, Tokico D-SPEC, and STi/SPT Version 7, can be made to fit in two ways:
- Using 2002-2003 Springs and Rear Strut Top Mounts: This method involves swapping to the older style springs and rear strut mounts to match the 2002-2003 strut design.
- Using 2004+ Style Components with a Spacer: Alternatively, you can retain your 2004+ style springs and rear strut top mounts by incorporating a Scooby921 strut spacer. This spacer compensates for the difference in strut length. It’s crucial to understand why this spacer is needed; detailed explanations are available on Subaru enthusiast forums.
It’s important to note that 05+ STi struts are not compatible with the 2004-2007 WRX and RS models. Furthermore, wagon models have specific strut considerations, which will be addressed in a later section.
Springs: Compatibility Across Impreza Models
Good news for Impreza owners: springs designed for the 2004-2007 RS or WRX models are generally interchangeable. This broad compatibility simplifies finding aftermarket spring options to achieve your desired ride height and handling characteristics.
However, there are nuances to consider. Aftermarket springs specifically engineered for the Impreza STi models are often too stiff for the standard WRX or RS struts. If you’re aiming for a balanced setup with stock struts, OEM STi springs can be a viable upgrade, offering a firmer ride without compromising strut performance.
If you are considering using springs designed for the 2002-2003 Impreza, remember that this necessitates using 2002-2003 Impreza struts and rear strut top mounts to ensure proper fitment. Refer back to the strut section for a comprehensive understanding of spring compatibility when using 2002-2003 struts.
Strut Tops and Camber Plates: Front and Rear Considerations
When addressing strut tops and camber plates, the 2002+ RS, WRX, and STi models exhibit good front-end compatibility. All front strut top mounts and front camber plates from these models are interchangeable.
For the rear, compatibility is slightly more nuanced. 2002-2003 rear strut tops are only compatible with 2002-2003 springs. Conversely, 2004+ style rear strut top mounts require the use of 2004+ style springs. Maintaining matching spring and strut top styles is essential for correct assembly and performance.
It’s also worth noting that 2002-2007 2.5RS, TS, and 2.5i strut tops are designed to be softer than both WRX and STi strut tops. WRX and STi strut tops, on the other hand, share the same stiffness level. It’s a common misconception that STi strut tops are Group N strut top mounts, which are even stiffer, but this is not the case.
Camber Bolts: Universal Fitment
Camber bolts offer a simple way to adjust your Impreza’s camber settings. The good news is that all 2002-2007 Impreza RS, WRX, and STi camber bolts are interchangeable and utilize a 14mm size. This standardization simplifies the process of finding and installing camber bolts for these models.
Strut Bars: Enhancing Chassis Stiffness
Strut bars are designed to improve chassis rigidity and handling. Front and rear strut bars from any 2002-2006 RS, WRX, and STi models will fit the 2004-2007 Impreza range.
However, front strut bar fitment for 2006-2007 WRX models can present a minor challenge. While 2002-2005 Impreza front strut bars will physically fit the 2006-2007 WRX, there may be clearance issues with the AC lines. For a hassle-free installation on 2006-2007 WRX models, considering strut bars specifically designed for these years is advisable.
Coilovers: Complete Adjustable Suspension Systems
For those seeking a fully adjustable suspension system, coilovers are a popular choice. Any complete coilover kit designed for the 2002-2007 RS, WRX, and 2004 STi models will fit.
Similar to struts, 05+ STi coilovers are not compatible with the 2004-2007 WRX and RS models. Always verify the model year compatibility when purchasing coilovers to ensure proper fitment.
Sway Bars and Sway Bar Mounts/Bushings: Fine-Tuning Handling
Sway bars play a crucial role in controlling body roll and improving handling. All rear sway bars designed for any 2002-2007 RS and WRX models are compatible. While STi rear sway bars will mount, their effectiveness is reduced due to mounting on the outside of the end links.
When it comes to sway bar bushings and mounts, there are model year specific considerations. 2004+ RS, WRX, and STi rear sway bar bushings are not compatible with 2002-2003 sway bar mounts. However, 2004+ RS, WRX, and STi rear sway bar mounts are an upgrade option for earlier models but necessitate using 2004+ sway bar bushings.
Front sway bar compatibility is more model-specific. Front sway bars for 2002-2007 WRX models will fit WRX models but are not compatible with RS models. The 2002-2007 Impreza RS requires a specific sway bar to clear the non-turbo headers. WRX and STi front sway bars will not fit an RS. Wagon models also have different front sway bar requirements, discussed later.
Endlinks: Connecting Sway Bars
Endlinks connect the sway bars to the suspension components. Front endlinks from any sedan 2002-2007 RS, WRX, or STi will fit sedan models. Wagon models have different front endlink requirements.
Rear endlinks for any 2002-2007 RS and WRX will fit both sedan and wagon models. However, STi rear endlinks are not compatible.
Other Suspension Components: Lateral Links, Control Arms, and More
Beyond the major suspension components, other parts also play a role in handling and alignment. All rear lateral links and trailing arms for 2002-2007 RS and WRX, and 2004 STi models are compatible with sedans, excluding wagon models. STi rear lateral links require STi rear endlinks and an STi rear sway bar for proper integration.
Front control arms for all 2002-2007 RS, WRX, and STi models are interchangeable. While 2006 WRX models feature aluminum control arms, the fitment remains the same. Wagon models again have different front control arm considerations.
Anti-lift kits designed for 2002-2007 WRX and STi models are universally compatible within these models. Fender braces, however, are not compatible with non-turbo models.
Steering rack bushings have a more specific fitment. 2006 Impreza and 2005-2007 Impreza STi models use the same steering rack bushings, which are not compatible with other applications.
WRX Wagon, OBS, and 2.5 RS Wagon Differences: Wagon-Specific Considerations
Wagon models within the 2004-2007 Impreza range have unique suspension requirements compared to their sedan counterparts.
Struts: Struts are wagon-specific. While sedan OEM and aftermarket struts and coilovers can be fitted to wagons, it will result in a loss of negative camber. This can be corrected using camber bolts and/or camber plates. The KYB GR2s and Koni inserts (when installed in gutted wagon struts) are notable exceptions as upgraded struts that retain stock camber on wagons.
Springs: Using sedan springs on a wagon often leads to a saggy rear end due to the wagon’s increased rear weight. Prodrive WRX springs are an exception. Wagon-specific spring versions are available from various manufacturers and are recommended for optimal wagon suspension setup.
Sway Bars: Wagon front sway bars are shorter than sedan versions and necessitate a wagon-specific fitment. While sedan front bars have been used in some cases with specific endlinks, wagon-specific bars are generally recommended.
Endlinks: Wagons require wagon-specific front endlinks unless you convert to sedan front control arms.
Other: Front control arms are different on wagons. Upgrading to sedan control arms provides a wider track, allowing the use of sedan front sway bars (offering more choices), and sedan struts without negative camber loss. Alternatively, you can retain wagon struts and gain negative camber with sedan control arms. This conversion to sedan control arms requires using sedan front sway bars and sedan front endlinks. While not strictly required, using sedan front axles is also recommended for this conversion. Rear lateral links also differ in wagons, and switching to sedan lateral links necessitates switching to sedan rear axles.
Conclusion:
Navigating suspension compatibility for your 2004-2007 Subaru Impreza requires attention to detail and understanding model-specific differences, particularly between sedans and wagons. By carefully considering the part type, model year, and specific Impreza variant (WRX, RS, STi, Wagon), you can confidently determine “will this part fit my car?” and ensure successful suspension upgrades or repairs. Always double-check part numbers and consult with automotive professionals when in doubt to guarantee correct fitment and optimal performance.
