The BMW E30 and E36 chassis, while both iconic in their own right, possess distinct suspension geometries. Swapping components between them, particularly the rear suspension, requires careful consideration and modification. This guide delves into the intricacies of adapting E30 compact trailing arms for use in an E36 chassis, exploring the challenges, benefits, and necessary modifications. We'll address common questions and concerns surrounding this conversion.
Why Swap E30 Compact Trailing Arms onto an E36?
The primary motivation for this swap often centers around cost-effectiveness and availability. E30 compact trailing arms are generally cheaper and more readily available than E36 components, making them an attractive option for budget-conscious builders. Furthermore, some enthusiasts appreciate the characteristics of the E30's rear suspension, potentially offering different handling dynamics compared to the E36 setup. However, it's crucial to understand that this isn't a straightforward bolt-on affair.
What are the Challenges of this Conversion?
This isn't a simple plug-and-play modification. Significant fabrication and welding are typically required. The mounting points on the E36 chassis differ substantially from those on the E30, necessitating custom fabrication of brackets and potentially modification to the trailing arms themselves. Furthermore, ensuring proper alignment and suspension geometry is critical for safe and effective operation. Improper installation can lead to handling issues, premature wear, and even potential safety hazards.
What Modifications are Necessary?
The necessary modifications extend beyond simply bolting on the arms. Key areas requiring attention include:
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Custom Fabrication of Mounting Brackets: This is arguably the most significant challenge. You'll need to fabricate brackets that securely attach the E30 trailing arms to the E36 subframe. This requires welding skills and precise measurements.
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Adjusting the Trailing Arm Length: The E30 and E36 trailing arms have different lengths. You might need to adjust the length of the E30 arms or modify the suspension mounting points to achieve correct geometry.
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Brake Line and Hardware Modifications: The brake lines and associated hardware will need to be adapted to fit the new configuration.
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Shock Absorber and Spring Compatibility: While you might be able to utilize existing E36 shocks and springs, careful consideration and possibly modifications are needed to ensure proper fitment and function.
Will this Affect my E36's Handling?
Yes, this modification will almost certainly affect the E36's handling characteristics. The altered suspension geometry will change the car's weight distribution, camber, and toe. The result could be improved handling in certain aspects, or it might introduce undesirable characteristics like oversteer or understeer. Proper alignment and suspension tuning after the installation are crucial to optimize handling.
What about Wheel Alignment and Geometry?
Precise wheel alignment and suspension geometry are paramount after this conversion. The changes introduced by the E30 trailing arms necessitate a professional alignment to ensure proper handling, tire wear, and overall safety. Improper alignment can lead to uneven tire wear, unpredictable handling, and a compromised driving experience.
Are there any alternatives to this conversion?
While this conversion might seem appealing due to cost, consider exploring alternative solutions. Repairing or replacing the original E36 components might be more straightforward and less prone to unforeseen issues. Furthermore, upgrading to aftermarket E36 suspension components might offer a more effective and safer path to improved performance.
This conversion is a significant undertaking requiring advanced mechanical skills, welding experience, and a thorough understanding of suspension geometry. It's not a project for beginners. Consult with experienced mechanics and enthusiasts before attempting this modification. Always prioritize safety and proper alignment for a safe and enjoyable driving experience.
