Why Upgrade the S2000 AP2 Suspension After Adding Power

The Honda S2000 AP2 is already a chassis that thrives on balance: a front-midship engine, near-perfect 50/50 weight distribution, and a double-wishbone suspension that delivers incredible feedback. But when you add forced induction, a turbo kit, or even a simple bolt-on tune that pushes the F22C past 250 wheel horsepower, the stock suspension’s limitations become glaring. The extra power overwhelms the factory dampers and springs, leading to squat under acceleration, excessive body roll, and a loss of traction that undermines every mod you’ve bolted on. Upgrading the suspension isn’t just an option—it’s a necessity to turn that extra power into usable speed on track or on the street.

A common misconception is that only coilovers matter. In reality, the entire system—springs, dampers, anti-roll bars, bushings, and even alignment—must work together. This article will walk you through why suspension matters, what components to prioritize, and how to choose parts that match your driving goals. We’ll also cover installation tips, tuning basics, and real-world testing so you can maximize your AP2’s potential without wasting money on flashy parts that don’t deliver.

The Critical Role of Suspension After Power Mods

When you increase horsepower, you change the vehicle’s dynamic envelope. The stock AP2 suspension was tuned for roughly 237–247 horsepower from the factory. Adding 50–100 more horsepower without upgrading dampers and springs results in:

  • Uncontrolled weight transfer – Hard acceleration lifts the front end and squats the rear, reducing steering precision and causing wheel spin.
  • Delayed cornering response – Softer factory dampers allow more body roll before the tires reach their optimal contact patch.
  • Increased tire wear – Poor control over camber and toe under load leads to uneven wear patterns.
  • Reduced driver confidence – Inconsistent feedback makes it harder to push the car to its limit.

Upgraded suspension re-establishes control. Stiffer springs reduce body roll, higher-rate dampers manage weight transfer, and adjustable components let you dial in alignment for the specific tire and track conditions you run. The result is a car that hooks up better on exit, turns in more sharply, and gives you the confidence to use every bit of that added power.

Understanding the AP2’s Unique Geometry

Unlike the AP1, the AP2 received revised suspension geometry: softer springs but a larger front anti-roll bar, more aggressive rear toe control, and revised damper valving. These changes make the AP2 more stable but also more prone to understeer under power if not corrected. After adding power, the rear end can become loose under braking and acceleration if the suspension isn’t stiffened and balanced. Knowing this helps you choose parts that address the AP2’s specific weaknesses rather than blind recommendations from forums.

Key Suspension Upgrades for Your S2000 AP2

Below is a breakdown of the most impactful upgrades, ranked by how much they improve handling for a modified power build. Always decide based on your primary use case—street, track, autox, or weekend canyon carving.

1. Coilovers – The Foundation

Coilovers replace the entire spring-and-shock assembly with a single unit that allows independent adjustment of ride height and, on higher-end units, damping (rebound and compression). For a power-modded S2000, coilovers are the single best investment because they let you:

  • Lower the center of gravity by up to 1.5 inches.
  • Increase spring rates to match your power level (common range: 8–12 kg/mm front, 10–14 kg/mm rear for street/track).
  • Tune rebound to control pitch under acceleration and braking.

Popular options include Öhlins Road & Track (best balance), KW V3 (great on-road compliance), and BC Racing ER series (budget but functional). Avoid ultra-cheap coilovers that use single-adjustment damping—you need separate rebound and compression for fine-tuning.

2. Anti-Roll Bars (Sway Bars)

Upgraded sway bars reduce body roll without increasing spring rates dramatically. This is important because after adding power, you want to keep the car flat for consistent aero and tire loading. A typical upgrade is a 32–35 mm front bar (stock is ~31 mm) and a 24–26 mm rear bar (stock is ~24 mm). The rear bar is especially important on the AP2 to balance the inherent understeer. Brands like Swift, Eibach, and Carbing offer adjustable bars that let you fine-tune roll stiffness front to rear.

3. Lowering Springs vs. Full Coilovers

Lowering springs (e.g., Eibach Pro-Kit, Swift Spec-R) are a lower-cost option that drops the car around 1 inch while using stock dampers. However, stock AP2 dampers are not valved for higher spring rates, so you’ll often get a bouncy ride and poor control. For a power-modded car, lowering springs are a compromise. They work for a mild bolt-on car (intake, headers, tune) but not for turbo or supercharged builds. Save the money and step up to coilovers if you exceed 300 whp.

4. Strut Braces and Chassis Reinforcement

The S2000 chassis is already stiff for its era, but adding power can flex the front strut towers under hard cornering. A front strut brace (upper or lower) reduces flex and improves steering precision. Rear lower braces (like the Carbing rear strut bar) also help. Don’t expect a night-and-day difference, but they are cheap and easy to install. Combine with polyurethane bushings for maximum effect.

5. Bushings and Alignment Components

Stock rubber bushings degrade over time and allow unwanted movement under load. Replacing control arm bushings with polyurethane or spherical bearings tightens up the suspension. Additionally, the AP2’s rear alignment is non-adjustable from the factory (only toe via eccentric bolts). After lowering, you’ll need adjustable camber arms or toe links to achieve correct geometry. Without them, you’ll wear tires prematurely and lose traction. SPC and Hardrace make good adjustment kits.

Choosing the Right Parts for Your Power Level

Here’s a practical guide based on common S2000 power ranges:

Power Level Recommended Upgrades Approx. Budget
Up to 280 whp Coilovers (entry-level), lowering springs, sway bars, alignment kit $1,500–$2,500
300–350 whp High-end coilovers (Öhlins, KW), adjustable sway bars, poly bushings $3,000–$4,500
400+ whp Race-oriented coilovers, spherical bearings, full adjustable suspension, wider wheels $5,000+

Note: These budgets include parts only. Installation and alignment will add $500–$1,000 unless you DIY.

Installation Basics for AP2 Suspension Upgrades

Installing suspension components on an S2000 is straightforward for anyone with moderate mechanical skills. However, there are a few AP2-specific tips:

Tools Needed

  • Floor jack and two jack stands (or a lift).
  • Impact wrench or breaker bar for stubborn bolts.
  • Spring compressor (for coilover removal if reusing top hats).
  • Torque wrench (critical for all suspension bolts).
  • Pry bar or ball joint separator (for sway bar end links).

Step-by-Step Overview

  1. Safety first: Chock the wheels, secure the car on stands.
  2. Remove wheels and inspect old components for rust or damage.
  3. Disconnect sway bar links and drop the sway bar if needed (for front coilover removal).
  4. Remove dampers/springs – On the front, unbolt the three top-hat nuts and the lower clevis bolt. On the rear, remove the lower shock bolt and the upper mount bolts inside the trunk side panels.
  5. Install new parts – For coilovers, pre-set ride height roughly to a safe starting point (about 1–1.5 inches lower than stock). Use the manufacturer’s recommended spring preload but avoid over-preloading.
  6. Reassemble – Torque all bolts to factory specs (front lower clevis: 47 lb-ft, rear lower: 60 lb-ft, top hats: 29 lb-ft).
  7. Align the car – This is non-negotiable. Set camber to about -2.0° to -2.5° front, -2.5° to -3.0° rear for street/track; caster around 6.0°; toe near zero front and slight toe-in rear (1/16" total).

Common Pitfalls

  • Over-tightening – Bolts on the S2000 are easy to strip. Use a torque wrench.
  • Not adjusting damping – Many people install coilovers and leave damping at factory settings (often too stiff). Start at 50% of full stiffness from soft and adjust based on feel.
  • Ignoring bump steer – If you lower the car a lot, the tie rod angles change. Consider aftermarket bump steer correction kits (e.g., from Ballade Sports) to maintain linear steering.
  • Driving immediately without settling – After lowering, drive the car gently for 20–30 miles to let the suspension settle, then re-check ride height and alignment.

Fine-Tuning Your Suspension Setup

Once installed, the real work begins: dialing in the setup to match your driving style and power delivery. Here’s how to approach it:

Ride Height

Aim for a drop of 1.2–1.5 inches front and rear (measured from center of wheel to fender lip). Lower than that will risk bottoming out on curbs or causing oil pan damage. Measure all four corners to ensure the car sits level. The AP2 has a slight forward rake from the factory; keep about ¼” higher in the front to maintain proper weight transfer under braking.

Damping Settings

Start with rebound (usually the adjuster at the top of the damper) set to 10–15 clicks from full soft for street driving. Compression (often at the bottom) can be set softer (15–20 clicks from soft). For track use, tighten both by 5–8 clicks but avoid going too stiff—otherwise the car will skip over bumps rather than gripping. Use the “one click at a time” method until you find the sweet spot.

Alignment – The Secret Sauce

A proper alignment tailored to power mods transforms the car. For a turbo S2000 that puts down 350+ whp, consider these baseline settings (on 245/40R17 or 255/40R17 tires):

  • Front camber: -2.8° to -3.2° (more if you want turn-in bite, but watch tire wear).
  • Rear camber: -2.5° to -3.0° (matching the rear helps with power-on traction).
  • Front toe: 0 to 1/16” toe-out (for sharper turn-in).
  • Rear toe: 1/8” toe-in (to prevent oversteer on throttle).

If you’re running a staggered setup, adjust rear camber to be slightly less aggressive than the front to promote stability.

Testing and Data Logging

Don’t rely solely on seat-of-the-pants. Use an accelerometer app (like Harry’s Lap Timer) or a simple G-meter to compare lateral grip before and after adjustments. A good target for a well-sorted AP2 on street tires is 1.0–1.1 g of lateral acceleration. If you’re under 0.9 g, you’ve got alignment or damping issues. Also log tire temperatures across the tread to confirm even contact patch.

External Resources and Community Knowledge

The S2000 community is rich with data. When building your suspension, consult these authoritative sources:

Also, consider joining local S2000 track days where you can ride along with experienced drivers to feel the difference a well-tuned suspension makes. Nothing beats real-world feedback.

Maintaining Your Upgraded Suspension

After upgrading, maintenance changes. Coilovers require periodic cleaning of the damper shafts to prevent debris from scratching the seals. Every 10,000 miles, check for leaks, looseness in bolts, and wear in bushing links. If you track the car, inspect after each event. A small leak in a damper can lead to a dangerous loss of control mid-corner. Also, rotate/adjust alignment every 5,000 miles or after any significant change in ride height.

Final Thoughts: Balancing Power and Handling

Upgrading the suspension on your S2000 AP2 after power mods is not a one-size-fits-all project. It requires careful selection of components that work together, proper installation, and ongoing tuning. The reward is a car that not only accelerates harder but also turns in with precision, holds a line through corners, and puts power down without drama. With the right setup, your AP2 will feel like a completely new machine—one that rewards your investment with every twist of the steering wheel.

Whether you choose a street-oriented coilover kit, sway bars, or a full race setup, the key is to match the upgrades to your power level and driving style. Start with a solid foundation (coilovers and alignment), then layer on bushings and anti-roll bars as your skills and budget allow. And remember: the best suspension upgrade is the one you actually tune and test. Don’t just bolt it on and assume it’s perfect—dial it in, hit the road, and enjoy the transformation.