C2 & C3 Corvette

The C2 and C3 Corvette are among the most iconic American sports cars ever built. Their styling remains timeless, but suspension, chassis rigidity, and overall vehicle dynamics are rooted in technology that is now more than 60 years old. The Speedtech Performance ExtReme IRS Chassis was developed to bridge that gap, preserving the character of the original Corvette while delivering the precision, confidence, and capability expected from a modern high-performance sports car.

Built from the ground up as a complete performance chassis, the ExtReme IRS platform is designed for enthusiasts who demand more than just a comfortable cruiser. Whether your goal is canyon carving, autocross, track days, or simply enjoying a world-class driving experience on the street, the ExtReme chassis transforms a vintage Corvette into a car with handling characteristics of a modern performance car.

Modern Corvette Performance Without Losing Corvette Character

The true appeal of the Speedtech ExtReme IRS Chassis is its ability to blend modern performance with classic Corvette styling. The car retains the timeless lines and unmistakable personality of a C2 or C3 while gaining the capability of a contemporary high-performance sports car.

The lowered stance, increased tire capacity, advanced suspension geometry, and modern chassis engineering work together to create a driving experience that feels generations ahead of the original platform. Wide tire fitment, increased grip, improved ride quality, and confidence-inspiring handling transform the car into a true dual-purpose performer equally at home on a road course or a weekend cruise.

ExtReme Front Suspension Geometry

A great rear suspension is only part of the equation. The Speedtech ExtReme chassis incorporates completely modern front suspension geometry engineered to eliminate many of the compromises found in the factory Corvette design.

The front suspension features optimized control arm geometry, improved camber curves, enhanced roll center characteristics, and modern steering design. The result is sharper turn-in response, increased front-end grip, improved stability during braking, and significantly more predictable handling at the limit. Speedtech pairs the system with modern steering technology that delivers connected feedback and confidence-inspiring precision.

Compared to a stock C2 or C3 Corvette, the difference is dramatic. Body roll is reduced, steering response is quicker, and the car remains composed during aggressive transitions. Drivers gain confidence because the chassis communicates clearly and responds consistently.

Independent Rear Suspension: Modern Performance, Vintage Corvette

At the heart of the ExtReme chassis is Speedtech's fully engineered Independent Rear Suspension (IRS) system. Unlike traditional solid axle designs, the IRS allows each rear wheel to react independently to road conditions, improving traction, ride quality, cornering stability, and overall vehicle control

The result is a Corvette that feels planted and predictable in every situation. Rough pavement no longer upsets the chassis, high-speed stability is dramatically improved, and corner exit traction is significantly enhanced. Whether you're driving aggressively on a road course or cruising on the highway, the IRS delivers a level of refinement and confidence that simply wasn't possible with the original suspension architecture.

Multiple Rear Suspension Options:

Traditional Coilover IRS

The traditional IRS package utilizes a direct-mount coilover arrangement that provides exceptional performance while maintaining a straightforward and proven design. This configuration offers excellent responsiveness, simplified setup, and easy serviceability.

For many enthusiasts, the traditional coilover system provides the ideal balance between track capability and street comfort. It delivers predictable handling, precise suspension control, and extensive tuning capability while keeping the chassis package simple and effective.

Overhead Cantilever IRS

For builders seeking the ultimate in suspension technology and packaging, Speedtech also offers its Overhead Cantilever IRS system. This advanced design relocates the shocks and springs into the chassis structure through a cantilever mechanism, reducing unsprung weight and improving suspension efficiency.

The overhead system also provides increased packaging flexibility, enhanced suspension motion control, and a unique appearance that showcases the engineering beneath the car. The design allows for rapid tuning changes while maximizing performance potential for serious track and competition use. Speedtech's cantilever IRS architecture was specifically developed to provide the benefits of a modern race-inspired suspension system while remaining fully streetable.

Total Suspension Adjustability

One of the biggest advantages of the ExtReme IRS Chassis is the extensive adjustability built into the front and rear suspension systems. Rather than forcing the owner to live with factory compromises, the chassis can be tailored to suit virtually any driving style or performance objective.

-Caster Adjustment

Caster plays a major role in steering feel and high-speed stability. The ExtReme chassis allows precise caster tuning to increase steering feedback, improve straight-line tracking, and enhance cornering confidence.

-Camber Adjustment

Proper camber settings maximize tire contact patch during aggressive cornering. Whether you're setting the car up for comfortable street driving or maximum track grip, camber can be dialed in to match the intended use.

-Toe Adjustment

Toe settings have a significant impact on vehicle stability and turn-in response. The ExtReme front and IRS systems provide precise toe adjustment, allowing owners to fine-tune handling balance and predictability.

-Ride Height Adjustment

Ride height can be adjusted to achieve the perfect combination of appearance, suspension travel, and performance. Whether you prefer a slammed Pro Touring stance or a more practical street-oriented setup, the chassis provides the flexibility to achieve the desired look and handling characteristics.

-Corner Weighting and Chassis Balance

The coilover-based suspension allows for accurate corner balancing, enabling experienced tuners to optimize weight distribution and chassis response. This level of adjustability is a major advantage for enthusiasts seeking maximum performance from their Corvette.

The result is a suspension system that can evolve with the owner. Street cruiser today, autocross car tomorrow, track-day weapon next season, the chassis is capable of adapting as your goals change.

Is the ExtReme IRS Chassis Right for You?

If your goal is to build the ultimate C2 or C3 Corvette - one that delivers modern handling, superior ride quality, extensive adjustability, and proven track capability, the Speedtech ExtReme IRS Chassis represents one of the most advanced solutions available.

This isn't simply a replacement frame. It's a complete performance foundation engineered to unlock the full potential of a vintage Corvette. For enthusiasts who want modern Corvette-like handling while preserving the style and heritage of America's sports car, the ExtReme IRS Chassis delivers exactly that.

Product Links:
1963-1967
 1968-1973
1974-1982

Video Links

Big Kids - https://www.youtube.com/watch?v=IqZB7flrOtk&t=74s

Part 1  - https://www.youtube.com/watch?v=VdaMAnhpcg0&t=21s

Sean Brinkley https://youtu.be/O4yg8EZqYeU?si=t6mCxhfZepj7WI4j