The Acura TL Type S: A Performance Sedan Legacy

Introduced as the sporty variant of the third-generation Acura TL, the TL Type S combined luxury amenities with a 3.5-liter V6 producing 286 horsepower and 256 lb-ft of torque. It came equipped with stiffer springs, a quicker steering ratio, and firmer dampers compared to the standard TL. However, even the factory-tuned suspension leaves room for improvement when it comes to aggressive driving. Lowering the center of gravity and reducing unsprung weight can transform the chassis feel. Installing aftermarket springs like those from Eibach is one of the most effective handling upgrades for this platform. The result is a more responsive, planted sedan that retains daily-driver comfort.

Understanding Suspension Geometry and Spring Rates

Before diving into installation, it helps to understand what the springs actually do. The spring rate (measured in lbs/in) determines how much force is needed to compress the spring a given distance. A higher spring rate reduces body roll but can increase harshness over bumps. Eibach engineers their Pro-Kit springs to offer a progressive rate: softer over small imperfections and stiffer as the suspension loads up during cornering. This preserves ride quality while sharpening turn-in response. The typical drop for an Acura TL Type S on Eibach Pro-Kit is about 1.0 to 1.4 inches front and 1.2 to 1.5 inches rear, depending on the exact part number (commonly 8321.140). Lowering the car also reduces the roll center shift and lowers the centroid of lateral forces, effectively making the suspension more resistant to body lean. Pairing the springs with aftermarket dampers (such as Koni Sport or Bilstein B6) is recommended for optimal control, but the factory shocks can still work well if they are in good condition.

Why Eibach Springs Stand Out

Eibach has been a trusted name in suspension manufacturing for decades. Their springs are cold-wound from high-tensile steel, shot-peened for fatigue resistance, and powder-coated for corrosion protection. Unlike generic lowering springs, the Eibach Pro-Kit for the TL Type S is engineered to work with the factory damper valving, meaning you don't necessarily have to replace your shocks immediately. Field reports from enthusiast forums such as AcuraZine confirm that the Pro-Kit eliminates the floaty feel at highway speeds and substantially reduces dive under braking. For owners who want a more aggressive drop and higher spring rates, Eibach also offers the Sportline series, which provides a more radical lowering but requires upgraded dampers to avoid bottoming out. For a street-driven TL Type S, the Pro-Kit is generally the sweet spot between performance and civility.

Preparing for Installation: Tools and Safety

Installing springs on a front-strut, rear-multi-link suspension like the TL Type S is a job best done over a weekend. Proper preparation prevents damage and ensures safety. Here is a list of essential tools:

  • Floor jack (3-ton minimum) and four jack stands
  • 19mm and 21mm sockets for the strut bolts and lower control arm
  • Torque wrench capable of 150 lb-ft
  • Spring compressor (manual or hydraulic; avoid using the vehicle's weight as a compressor)
  • Breaker bar and impact wrench (optional but helpful)
  • Penetrating oil (e.g., PB Blaster) for rusted bolts
  • 8mm, 10mm, 12mm, 14mm, 17mm sockets for various fasteners
  • Safety glasses and mechanic's gloves

Before lifting the car, loosen the lug nuts on all four wheels while it is on the ground. Work on a level surface and always use jack stands; never rely solely on a hydraulic jack. It is wise to have a helper when aligning the spring into the upper strut mount.

Step-by-Step Installation Guide

Front Suspension Disassembly

  1. Raise the front of the vehicle and place jack stands under the frame rails or subframe. Remove both front wheels.
  2. Remove the brake line bracket from the strut housing (10mm bolt). Do not disconnect the brake lines.
  3. Remove the sway bar end link nut (17mm) and detach the end link from the strut. This allows the strut to swing free.
  4. Support the lower control arm with a jack to relieve tension on the lower strut bolt. Remove the two lower strut bolts (19mm) that secure the strut fork to the steering knuckle.
  5. Inside the engine bay, remove the three strut top mount nuts (14mm). Lower the entire strut assembly out from the wheel well.
  6. Place the strut assembly in a spring compressor. Compress the factory spring until it is free of the top mount. Disassemble and remove the stock spring.
  7. Install the Eibach spring onto the factory damper, ensuring the ends of the spring align with the lower perch and upper rubber isolator. Use a new bump stop if the old one is worn.
  8. Compress the new spring just enough to reinstall the top mount. Torque the center nut to 22 lb-ft (per service manual). Reattach the strut to the vehicle and torque all fasteners to factory specs: lower strut bolts to 116 lb-ft, top mount nuts to 28 lb-ft, and sway bar end link nut to 33 lb-ft.

Rear Suspension Disassembly

  1. Raise the rear of the vehicle and remove the wheels. The rear spring is separate from the shock absorber.
  2. For the rear, you need to access the lower control arm. Remove the shock lower bolt (17mm) from the knuckle. Inside the trunk, remove the upper shock mount nuts (12mm) and pull the shock out.
  3. To remove the spring, lower the lower control arm using a jack until the spring can be pulled out by hand. On the TL Type S, the spring seats into a lower rubber isolator and an upper pocket in the chassis.
  4. Swap the isolator onto the new Eibach spring and position the spring. Raise the control arm back into place, ensuring the spring is seated correctly. Reinstall the shock and torque the lower bolt to 43 lb-ft, upper nuts to 16 lb-ft.
  5. It is critical to tighten all suspension bolts with the suspension loaded (weight of the car on the wheels) to prevent bushing preload. Reinstall wheels and lower the car to the ground before torquing the lower control arm pivot bolts (if loosened) to 119 lb-ft.

Post-Installation Alignment and Break-In

After the springs are installed, the ride height will settle slightly over the first 100–200 miles. It is common to see a further drop of ¼ inch. Do not drive aggressively until you get a professional alignment. The lowered ride height changes the toe and camber. A four-wheel alignment using the factory specifications will restore proper tire wear and steering feel. Many owners set the front camber to about -1.0° for improved cornering without excessive inner tire wear. Tire Rack’s suspension guide explains why alignment after lowering is crucial. The Eibach springs will eventually settle; after 500 miles, check all bolts for proper torque.

Real-World Performance Results

Drivers who have installed Eibach Pro-Kit springs on their Acura TL Type S consistently report several measurable improvements:

  • Reduced body roll: The car stays flatter through slalom-style maneuvers. Lateral acceleration improves from roughly 0.85g to over 0.90g on summer tires.
  • Sharper turn-in: The reduced weight transfer allows the front tires to bite sooner. Steering feel becomes more direct with less dead zone on center.
  • Improved braking stability: Nose dive under hard braking is reduced by about 40%, giving the driver more confidence in emergency stops.
  • Subtle drop in ride comfort: On rough pavement, the suspension transmits more vibration, but the progressive nature of the springs prevents harsh bottoming. Most owners find the trade-off worthwhile for the handling gain.
  • Aesthetic upgrade: The car sits with a purposeful rake, closing the wheel gap significantly. Many choose to complement the springs with 18-inch wheels and performance tires.

For context, on the Eibach official Pro-Kit page, the company claims a 30–40% reduction in body roll and improved steering response. These claims align with real-world experiences across the TL community.

Frequently Asked Questions

Do I need to replace my dampers with Eibach springs?

Eibach Pro-Kits are designed to work with factory dampers in good condition. However, if your TL Type S has high mileage (over 80,000 miles), the original shocks may be worn. Replacing them with KYB Excel-G or Koni Orange dampers at the same time will yield the best ride quality and longevity.

Will Eibach springs affect my vehicle warranty or insurance?

Suspension modifications may void the factory warranty on suspension components, but they do not void the entire vehicle warranty. Check your local regulations. Inform your insurance provider; some companies may increase the premium for modified suspensions.

How long does installation take?

A first-time installer with proper tools will need about 4–6 hours. Experienced mechanics can complete the job in 2–3 hours.

Can I install Eibach springs without a spring compressor?

No. Attempting to disassemble a strut without a spring compressor is extremely dangerous. The spring can eject with lethal force. Use a professional-grade spring compressor or have a shop perform the assembly.

Conclusion

The Acura TL Type S is a compelling platform for affordable performance. By installing Eibach Pro-Kit springs, you address the car’s main handling limitations: excessive body roll, soft turn-in, and a floaty highway feel. The installation is well within the reach of a competent DIY mechanic, and the results transform the car from a comfortable cruiser to a genuinely engaging sport sedan. Whether you are carving back roads or simply enjoying a more confident daily commute, the Eibach spring upgrade delivers a noticeable improvement in both dynamics and aesthetics. For further reading and owner experiences, the AcuraZine performance modifications forum is an excellent resource. As with any suspension modification, invest the time in a proper alignment and consider pairing the springs with upgraded dampers for the best possible results.