SKU: 140233 IRS Category:

ExtReme Corvette 1968-1982 C3 Chassis With Independent Rear Suspension

$32,349.00$35,349.00

Independent Rear Suspension (IRS) is the ultimate expression Pro Touring to make your C3 Corvette drive like a modern super car.  Corvettes from the 60s were manufactured to perform well using design theory from the 1950s, but what about those who want more form their Corvette? Speedtech Performance offer our award winning cantilevered IRS to achieve you driving goals.

EXTREME CHASSIS WITH INDEPENDENT REAR SUSPENSION FEATURES AND BENEFITS:

  • Box welded construction with tabbed through frame gusseting for added torsional rigidity
  • Choice of two different IRS systems, Low Mount Shock and High Mount Cantilevered Shock
  • Significantly increased rear shock motion ratio allows for better rear grip with lower spring rate
  • Fully adjustable rear wheel alignment – Camber, Toe, Bump-Steer
  • Exclusively equipped with forged 7075 Aircraft Aluminum ExtReme spindle (more info below)
  • Up to 30 degrees of steering angle equal to or slightly more than O.E.
  • Corrected Ackerman for better grip while cornering up to 20% more inside tire grip when cornering
  • Corrected scrub radius for large diameter wheels in wider widths
  • Virtually zero bump steer – .005” standard over full travel (can be tuned)
  • Industry leading design for lower roll center optimized for each chassis
  • Excellent comfort on the street, durable for autocross & track days
  • Increased shock length providing more suspension travel
  • 78% motion ratio front for faster shock response and more precise control
  • 3-piece Chromoly tubular splined sway bar standard and a variety of spring rates available
  • Sway bar arms are 3 position adjustable for tuning without changing bar
  • Front and rear ride height adjustments accommodate your vision for styling of the finished truck
  • Rear Roll Center is adjustable over based on lower control arm mounting position
  • Dutchman 9” alluminum center housing
  • Half-shaft axles using 35 spline RCV-934 C.V. Joints rated to 1200 HP (option for 1800 HP rating)
  • Uses factory body mounts

EXTREME CHASSIS WITH INDEPENDENT REAR SUSPENSION INCLUDES:

  • Full ExtReme Chassis designed exclusively for Speedtech Performance Independent Rear Suspension
  • Custom designed upper and lower control arms with high clearance  to accommodate wide wheels
  • Durable Sweet Mfg. dual power rack and pinion steering
  • JRI Speedtech Performance custom valved single adjustable coil over shocks, spring rates of your choice included
  • Tuned, adjustable, splined front sway bar with spring rate options for street, pro-touring/auto cross and road course
  • Exclusive ExtReme forged spindles with C7 hubs and maintenance free sealed bearing
  • Fully adjustable transmission cross member that will accommodate all engine and transmission combinations
  • Billet aluminum High Mount actuating rocker arms (high mount system only)
  • Speedtech Performance exclusive ExtReme forged spindles
  • Outer C7 33 spline stub axles
  • 35 spline EMPI 934 CV Joints
  • Hy Tuff 1/2 Shaft Axles
  • Dutchman Aluminum Housing
  • Your choice of gear ratio
  • JRI single adjustable coil over shocks valved for Speedtech Performance,  JRi springs with your choice of spring rate
  • All IRS packages come standard with E Brake

SPEEDTECH PERFORMANCE FORGED SPINDLES FEATURES AND BENEFITS:

  • Included with all ExtReme front suspensions and only available from Speedtech Performance
  • We took the best forged aluminum spindle made and made it better
  • Forged from high quality, light weight 7075 aerospace aluminum
  • Optimized geometry unlike in any other Corvette style spindle in the industry
  • Significantly improved KPI/SAI angle
  • Scrub radius optimized for KPI/SAI changes and larger wheels
  • Requires less caster to achieves optimum tire contact patch
  • Billet steering arm provides increased Ackerman angle
  • Achieves optimum tire slip-angles to provide increased front tire grip
  • Maintains optimum tire grip with less backspaced wheels
  • Brakes caliper bolt pattern is carryover from C5 & C6 Corvette opening up many options
  • Comes standard with maintenance free factory GM C7 Corvette hubs & bearings
  • Excellent design attributes for street cars and race cars
  • Our Spindle provides a more refined and precise driving experience in all situations

ADD ONS TO HELP YOUR BUILD GO MORE SMOOTHLY: 

  • LS, LT, SBC, and BBC Engine and adapter plates
  • Urethane engine and transmission mounts
  • Stainless steel 1 7/8″ headers for most engines
  • Stainless-Steel double joint steering shaft kit
  • Splined adjustable 3 piece rear sway bar
  • Rear end center section with your choice of final drive ratio
  • Aluminum Third Member with your choice of gears
  • Brake packages from Baer or Wilwood with E Brake
  • Full Floater 9″ rear axle
  • Ididit tilt steering column*
  • Stainless-Steel Rick’s fuel tank with pump options
  • Wheels and Tires
  • Bespoke PRC Aluminum cross flow radiator with twin Spal fans, shroud, billet overflow, billet rad cap all wiring and relays custom built to fit the Tri5 ExtReme frame

 

Note: Oil pan compatibility with chassis is specific and the pan will need to fit around the steering rack. Ask your sale person for a recommendation.

Chassis orders will be confirmed over the phone. A sales person will call you for a no cost consultation to discuss the specific details of your project and ensure you are provided with the very best customer experience.

*Factory steering columns have the incorrect length and will not work with the ExtReme suspension components. We recommend an Ididit steering column for best results. Please speak to your salesperson to order from us or to obtain the correct part number.

Note: All chassis orders will have a $900 crating fee plus truck freight shipping added on at the time of processing. These chassis can only be delivered to a shipping terminal or a business with a loading dock and/or forklift access.

Be sure to ask your sales rep about these different options to customize your frame to meet the needs of your project.

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